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The expression of barnase in tobacco is under the control of sulfhydryl endopeptidase medicine 0552 500mg meldonium with mastercard. Recovery from the barnase effect is managed by barnstar under the control of a heatshock promoter treatment emergent adverse event order meldonium 500 mg without a prescription. It is assumed that this autosomal locus was retrotransposed in an early ancestor to the Y chromosome medicine ok to take during pregnancy buy cheap meldonium 500mg. It appears that the chromosome 6p12 sequence is a processed pseudogene of the Xq26 sequence and there are similar sequences in chromosomes 1 medications to treat anxiety generic meldonium 250mg with visa, 4 symptoms pneumonia purchase 500 mg meldonium amex, 9 and 11 symptoms 7 dpo bfp meldonium 500 mg without prescription, all retrotransposed from Xq26. In concert with RcsC/B and DnaK and GrpE, it induces the cps capsule polysaccharide operon of E. The sequences which do not match fail to hybridize and are believed to cause the disease. The relatively rapid mass screenings were expected to identify individuals predisposed to particular hereditary differences (diseases). Reaction Norm: this denotes the range of phenotypic potentials of expression of a gene or genotype. Usually, the genes do not absolutely determine the phenotype but they permit a range of expressions, depending on the genetic background, developmental and tissue-specificity conditions and the environment. Reaction norm or water lily (farnwort): above water the leaves are different from below water (Goebel, K. Reading Disability: dyslexia Reading Frame: the triplet codons can be read in three different registers, starting with the first, second or third, however, only one may spell the correct protein. On an average human hereditary disease is due to the inability to readthrough translation-termination nonsense mutation. Unfortunately, it is not useful for clinical purposes because the effective dose produces serious side effects. The hemagglutinin coding-segment assists in preventing the neutralization of antibodies of humans not previously exposed to the avian flu virus. In vertebrates cohesin is removed during prophase but Scc1 remains associated with the centromeres when separin cleaves this protein and thus facilitates the metaphase-anaphase transition. Inside this cavity projecting toward the axis of the helix are mobile loops L1 and L2 representing the binding sites. RecA appears to play a role in the segregation of the bacterial chromosomes (Ben-Yehuda S et al 2003 Science 299:532). The RecA prokaryotic gene when equipped with the nuclear localization signal and transformed into tobacco cells increases sister chromatid exchange by $two-threefold. Structural and functional homologs of the bacterial RecA are UvsX (phage), Rad51 (eukaryotes) and RadA (archaea). RecA-Independent Recombination (illegitimate recombination): this may use three pathways (i) simple replication slippage, (ii) sister chromatid-associated replication misalignment, and (iii) single-strand annealing. Single-strand annealing takes place after palindromic sequences within each strand fold into hairpin structures within the strands. RecA-independent recombination occurs at extremely low frequencies and is less responsive to the extent of homology. RecA-independent recombination in Escherichia coli is depressed by the redundant action of singlestrand exonucleases. In the absence of multiple single-strand exonucleases, the efficiency of RecAindependent recombination events, involving either gene conversion or crossing over, is markedly increased to levels rivaling RecA-dependent events. R Receptor Down Regulation 1641 RecG: this unwinds the leading and lagging strands at a damaged replication fork and may contribute to replication restart if it was stalled by the damage. Receptacle Receptin: this is a natural or engineered microbial protein which can bind to a mammalian protein. The site responding to the controlling element (transposase) as originally called by Barbara McClintock the components of the Spm transposable systems in maize. Receptors may be located within the plasma membrane (transmembrane proteins) or are intracellular and bind ligands, which penetrate cells by diffusion. Cell surfaces can be tagged by unnatural, exogenous molecules facilitating the therapeutic targeting of surface glycans and imaging disease progression (Prescher J et al. The cell surface has a reduced number of them because of receptor down regulation. This mechanism eliminates the autoreactive B cells when confronted with self-antigens. Receptor-Mediated Gene Transfer: Cell surface receptors may internalize their ligands by endocytosis. A fusogenic peptide or a disabled adenovirus may facilitate the entry of the complex into the cell by endocytosis and transported with the aid of an endosomal vehicle. With the assistance of asialoglycoprotein receptor the gene may be targeted to hepatocytes or with a mannose receptor it may be targeted to macrophages. The transferrin receptor facilitates targeting erythrocytes; polymeric immunoglobulin receptors may aim the gene construct at the lung epithelia; other receptor and ligand combinations permit targeting to other cells or tissues. It dephosphorylates negative regulatory C-terminal tyrosine residues of the Src family kinases. Receptor Serine/Threonine Kinases: these are the receptors of serine/threonine phosphorylating enzymes. They are the major types of plant receptor kinases, unlike in animals where receptor tyrosine kinases dominate. Hepatocyte growth factor receptor defects are responsible for the papillary renal cell carcinoma. Hereditary lymphedema receptor disease is due to the vascular endothelial growth factor. Congenital pain with anhidrosis is caused by defects in the neurotrophin receptors. The phosphorylation results in dimerization or dimerization results in phosphorylation and activation. The various regulatory proteins recognize the different phosphorylated tyrosine residues in the receptor. Upon binding to their specific sites they may also be phosphorylated on their own tyrosine residues and become activated. The different receptors and the associated proteins may control the separate or interacting signaling pathways. Receptor Tyrosine Phosphatase: this binds protein tyrosine phosphates and splits off phosphate groups. Receptor-Mediated Endocytosis: this is a very efficient delivery system of macromolecules (such as cholesterol), that adheres to coated pits, into cellular organelles. They can be extracellular receptors that respond to outside signals reaching the cells. They may be located on the surface of the cell membrane or within the membrane but their ligand-binding domains are exposed to the extracellular space. Recessivity is not necessarily an absolute lack of expression of the gene (except in null alleles) because extremely low level of transcription/translation may not be observed by a particular type of study but may be detectable by a finer analysis. Recessive Lethal Tests, Drosophila: Basc, ClB method, sex-linked recessive lethal, autosomal recessive lethal assay Recessive Oncogenes: these are tumor-suppressor genes such as encoding p53. Recipient: Bacterial cells of the Fstate receive genetic material from the donor F+ strains. In cases when cytoplasmically determined differences exist between the two parents, the F1 offspring bears greater resemblance to the female parent that usually transmits the cytoplasm. These reciprocal differences may persist indefinitely in the advanced generations. Although reciprocal differences are normally most obvious in plants, inanimal hybrids. Reciprocal Recombination: this is the most common exchange between homologous chromatids at the 4-strand stage of meiosis in eukaryotes. In the case of single crossing over in an interval, two parental types and two crossover strands are recovered. In conjugational transfer in bacteria the reciprocal products of the event are not recovered and their fate is unknown. In sexduction and specialized transduction reciprocal recombination may also take place in bacteria (see. As a consequence, generally 50% of the gametes of the translocation heterozygotes (formed by adjacent distributions) are defective because they do not have the correct amount of chromatin. The code words may be interpreted in different ways and stop codons may specify selenocysteine, tryptophan and glutamine. Compton effect Recombinagenic: this may be involved in genetic recombination at an increased frequency. Recombinant: Refers to an individual with some of the parental alleles reciprocally exchanged. The antibody gene fragment can be fused to a bacterial signal sequence enabling the direction of the molecule into the periplasmic space where chaperones can properly fold the engineered protein. Recombinant antibodies can be modified with the battery of tools of molecular biology and different properties can be added to them. Recombinant Congenic: An outcross is followed by several generations of inbreeding in order to minimize the background genetic variations. Since then evidence has accumulated indicating that some of the fears were not entirely justified, except by the wisdom of caution with a hitherto unknown and unused procedure. To avoid safety risks various levels of containments were made mandatory, depending on the organisms used, to prevent the accidental escape of genetically engineered organisms. Certain types of gene transfers were entirely prohibited to avoid contagions and highly toxic products. Obviously, such a mass of bacteria is not likely to occur because the earth may not support it. To get an idea of what this volume is a comparison can be made: wheat production of the world in 1980 was only 4. To avoid any problem, nevertheless, government authorization is required in all countries where this technology is used, for the release of any genetically engineered species (microbes, plants, animals) for the purpose of economic utilization. Objections to such carefully tested releases are still raised, based not so much on public concern as on personal or political interests and most commonly because of ignorance. Such toxins are botulinum, tetanus, diphtheria and Shigella dysenteriae neurotoxin. Specific approval is mandatory for cloning in Escherichia coli K12 genes coding for the biosynthesis of toxic substances, which are lethal to vertebrates at 100 ng to 100 mg per kg body weight. In the case of animals, the calculation is as follows: R (the frequency of discordant individuals) is R = (4r)/(1 + 6r) where r is the recombination in any single gamete. Since interference within very short distances is practically complete, the distance in cM is d = 100r. In plants, the frequency of recombinant monoploid gametes is calculated by using the same formula r = R/(2 - 2R) where R is the frequency of homozygous recombinant diploid individuals. Recombination is most common during meiosis but mitotic recombination also takes place. The mechanism of meiotic and mitotic events is not necessarily identical (see. Independent segregation and reassortment are outside the realm of this term, according to the original definition given by H. Data obtained have R A B b B b B Parental Recombinant Recombinant Parental A a a b B b Synapsis in meiocyte Chiasma Crossovers at 4-strand stage Gametes Figure R20. Cytological representation of recombination between homologous chromosomes in coupling phase. The frequency of recombination depends, however, on the distance between the two loci considered. If crossing over takes place in all meiocytes between the bivalents, the frequency of recombination is 50%. If only half of the bivalents undergo crossing over in that particular interval, the recombination frequency will be 25% because, say in 4 meiocytes with (16 chromatids) 4/16 = 0. The maximal recombination frequency by a single crossing over is 50%; the minimal may be extremely rare in case the linkage is tight. A rare photograph of the three men who independently made basic discoveries in recombination. In the middle is Alfred Henry Sturtevant who as an undergraduate student published the first linkage map of Drosophila in 1913 (Science 58:269). Bridges in 1925) (Genetics 10:403) demonstrated that crossing over takes place at the four-strand stage. The so-called desert" sequences display low and the "jungle" stretches high recombination and this is depicted in the diagram. Recombination by Replication: At the beginning of the twentieth century William Bateson suggested that recombination is basically associated with the process of replication. Weber; see also Yu A et al 2001 Nature [Lond] 409:951) At that time neither of these phenomena was sufficiently understood or could even be hypothesized meaningfully. However, the discovery of gene conversion remained a puzzling phenomenon although it was observed that about 50% of the gene conversion events involved flanking marker exchange. Holliday and other molecular models of recombination (during the 1960s and 1970s) permitted interpretation of classical crossing over and gene conversion without significant replication. The chi elements block nuclease activity and assist the initiation of replication.
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After fermentation (silage) symptoms type 1 diabetes generic meldonium 500mg with mastercard, dicoumarol is formed that is very toxic due to its anti vitamin K and hemorrhagic effects treatment 3rd degree heart block purchase 500mg meldonium otc. Plant breeding efforts have successfully reduced the coumarin content of some Melilotus albus varieties symptoms of breast cancer 500mg meldonium otc. Coumarin Cotyledon: Seed leaf (actually an imprecise term because the seed before emergence may already have the initials of several leaves) medications for anxiety order meldonium 250 mg mastercard. At emergence treatment centers in mn buy 500 mg meldonium, the dicotyledonous plants have two cotyledons medications by mail cheap 250mg meldonium with visa, which have a nutritive storage role before and for awhile after germination. The monocots have only a single Coumarin-Like Drug Resistance: Due to an autosomal dominant gene some individuals are resistant to coumarin-like compounds such as warfarin, bishydroxycoumarin and phen-indione (anticoagulants). Count-Location Models 431 these compounds are therapeutic agents in certain cases of surgery and in thromboembolic (blood clot forming diseases blocking arteries) diseases. These predictions are based on family histories, cytological, biochemical, and molecular analyses. In Northern Europe, almost 12/1,000, and worldwide about 17/1,000 births are affected by singlegene defects. The completion of the physical mapping of the human genome will greatly improve the potentials of accurate genetic counseling by the availability of appropriate probes and nucleotide sequence information. Genetic counseling should be sought before marriage or procreation in families where risk is indicated. The analyses may involve the prospective parents or the fetus may also be examined by amniocentesis. Under some circumstances of very high risks, termination of pregnancy may be opted for where there are no moral and/or legal objections. The physicians or geneticists provide all the relevant facts but do not recommend the action(s) to be taken. Sometimes the counselor may, however, face the dilemma whether to reveal nonpaternity if this information does not entail health-related problems or if the diagnosis would jeopardize the emotional status of the counseled. If the families compensate for the aborted fetuses with new pregnancies, the frequency of the deleterious genes will rise in the population because the carriers may transmit the defective alleles and the problems are only postponed. If the carriers of serious hereditary defects refrain from reproduction, the frequency of these genes is supposed to decline eventually. The genetic counselor is a physician thoroughly trained in medicine and genetics and its cytogenetic, molecular, and statistical aspects, and is expected to be familiar with all the relevant techniques involved. Very often, because of the small family size, penetrance, expressivity problems, variability of the syndromes, difficulties in obtaining candid information of family histories, especially about hereditary diseases with social stigmas, even the best qualified counselor may encounter difficulties. Besides being a good geneticist and an experienced physician, he/she must have sufficient background in psychology and ethics. Genetic and medical facts must be explained in terms easily understood by the families involved, whose level of education may vary from case to case. The counseling may be only limitedly effective because of problems in communication or the inadequate biological/ genetical education of the counselee. Counseling is not supposed to follow any eugenic goal and is expected to be nondirective. The clients must be aware that genetic counseling may prevent family trauma, and may offer relief from nagging anxieties in cases when the recurrence risks are low. Also, some anomalies may be phenocopies and the genetics risks involved are practically nil. Since 1981, the American Board of Medical Genetics or the American Board of Genetic Counseling certifies genetic counselors. Count per Minute: cpm Countercurrent Distribution: Countercurrent distribution partitions relatively small molecules between two liquids that are polar to a different extent. Both liquids are moved in a special apparatus in opposite direction between steps of equilibration. Count-Location Models: Count-location models consider that chiasmata are distributed uniformly and independently along the length of the chromosome. C 432 Counterselection C Counterselection: As per counterselection, in a hybrid population the two parental strains (each resistant. Many genes are apparently involved but all appear to be pleiotropic and the mutations recovered affect more than one unrelated function. Some are affected in sex determination, others are visual or olfactory mutants or affect female receptivity or male fertility, or circadian rhythm, and others are involved in the "courtship song" of the flies (generated by the vibration of the wings). This receptor is located in about 20 male-specific gustatory bristles on the male foreleg (Bray S, Amrein H 2003 Neuron 39:1019). A better understanding of neuronal function and the availability of selection techniques will promote progress in this field. This as well as other behavioral traits can now be subjected to genetic and neurobiological analyses. News services reported that Prince Charles and Diana Spencer are 7th cousins once removed (see. Infant death rate during the first year of life among children of first cousins is approximately double relative to that in the general population. In India, the marriages between first cousins, in some communities, were as high as 30% in the not-too-distant past. Covalent bond Covalently Closed Circle: A circular macromolecule (plasmid) in which all the building blocks are covalently linked and thus there are no open ends. Covariance: correlation Covarion Theory: the covarion theory interprets evolution on the basis of varying codons in a lineage-specific manner among the sites. Diagram of the relations of the 7th cousin once removed CpG Islands 433 Cowpea (Vigna unguiculata): A food and fodder crop of the tropics and subtropics primarily. Several drugs contain Cox-2 inhibitors to protect from inflammation, arthritis, and other symptoms of disease. Humans, monkeys, and suckling mice are susceptible to them and the viruses may cause damage to the nervous system, the respiratory and alimentary tracts, muscles, and internal organs, and may even induce autoimmune disease. Coxsackie B4 viral infection is associated with insulin-dependent diabetes and shares similarity with the Langerhans islet autoantigen glutamic acid decarboxylase. Coyote: Canis latrans (2n = 78), the North-American canine; it can interbreed with domestic dogs (2n = 78) and the wolf (2n = 78). These must overcome the resistance of the epidermis (corneum striatum) by fluidization of the lipid bilayer and should not cause irritation by denaturing the proteins in this layer. CpG Motifs (Cytosine-Guanine): CpG motifs of bacteria in unmethylated state induce murine B cells to proliferate and secrete antibodies. The doublets in these islands (especially C 434 CpG Suppression C in housekeeping genes) are protected from methylation and are instrumental in the transcription of about half the mammalian genes. By computationally mapping all NotI or other methylationsensitive restriction enzyme sites, methylation events can be defined with single nucleotide precision through the entire genome. The methylation-sensitive enzymes do not cleave the normal recognition site when the C is methylated. Therefore, the methylation status (silencing/expression) can be assessed in a tissue-specific manner (Ching T-T et al 2005 Nat Genet 37:645). Some regions of the genomes are relatively low in CpG sequences and they may be methylated during most of the life of eukaryotes. Mutation occurs in the ankylosis gene that encodes a 492-amino acid transmembrane protein controlling pyrophosphate level and it is expressed in the joints and in other tissues. This system of photosynthesis fixes carbon with the aid of phosphoenolpyruvate carboxylase, and generates the C4 oxaloacetate, as in other C4 plants, rather than through ribulose-1,5-bisphosphate carboxylase/oxygenase, as in C3 plants. The clinical symptoms involve postural and locomotive defects due to brain and muscular anomalies and very low creatine excretion. Creationism: the doctrine about how the universe came into existence based on an oracle, and suggesting that organisms are as we see them at present because they have been so created and ordained. Some types of creationist ideas exist in many religions, including Hinduism (Hare Krishnas), and native American and Pagan religions. Creationism is not an entirely monolithic view, variations exist but all creationist ideas are united in negating evolution as presented by modern science. Several Christians, Roman Catholics, and Protestants accept evolution by assuming that God could have created the evolutionary mechanism, which led to the development of the biological systems as we experience them. The fossil record is a serious obstacle to the logic of creationism, and posits a difficulty in explaining its divine purpose. I refuse to accept the view that there are statements in science which we have, resignedly, to accept as true merely because it does not seem possible, for logical reasons, to test them. The aim is to identify knowledgeable experts in targeted categories such as in the fields of human genetics and nanotechnology, and to then ask these experts to nominate highly creative research. The aim is an understanding of the institutional and organizational conditions under which creative researchers have worked. It is hoped that the knowledge gained from the case studies will facilitate recommendations about the design of science policy to support innovative research. Credible Interval: the credible interval is similar to the confidence interval; and is calculated on the basis of posterior probability distribution. It can also be used in various eukaryotes for mediating site-specific recombination or chromosomal breakage (see. The Cre/ loxP system has been successfully exploited for sitespecific recombination and the generation of knockouts. The Cre protein (38-kDa) is a recombinase with specific recognition for the 34 bp locus of crossing over of P1 (loxP), a pair of palindromic sequences and recombination takes place within the 8 base central core (underscored at the sites delineated by red line. Note the inverted repeats left and right from the underscored octad signs (see. Cretaceous Period: 137 to 63 million years ago when the first human ancestors appeared. These symptoms overlap with Gerstmann-Straussler disease and the two are probably identical basically, although within both diseases different types of manifestations have been observed. The diseases are not limited to humans but in sheep (scrapie), goat, and rodents highly similar nerve degenerations have been described. The most commonly observed ProLeu replacement at codon 102 was attributed to the ataxia symptoms, but changes at Figure C179. Crepis: Composite flowers with chromosomes favorable for cytological studies (see. The injection of infected brain material into chimpanzees and other animals reproduces the disease. These diseases occur in a familial manner, and it is not exactly known when and how the genetic determination of the degeneration occurs. It has been detected among all ethnic groups; in some its frequency is much higher than in others. In addition, 41 to 47% of the cases observed were familial whereas in some other populations only 4 to 8% appeared familial. This observation appears similar to that involving the prevention of viral superinfection by another strain of the virus. Cri du Chat (cat cry): A deletion in the short arm of human chromosome 5 involves mewing like voice, mental and growth retardation and other disorders. C181) is a migrating species (traveling 2 km/day); the migration is driven by the need of salt of the large population. After viral challenge, bacteria integrate new spacers derived from phage genomic sequences. Removal or addition of particular spacers modify the phageresistance phenotype of the cell (Barrangou R et al 2007 Science 315:1709). The recessive genes follow the pattern of inheritance of the X chromosome; they are expressed in the hemizygous male but only in the homozygous female (see. In case the female is heterogametic and the male is homogametic, like in the Lepidoptera or birds, the inheritance follows the mirror image of what is shown in the diagram. Some of the male grandchildren of colorblind grandfathers will be color-blind, although their sons (the fathers of the grandsons) have normal vision. Therefore, it may be important to know how many individuals are needed in F2 to find at least one of this desired phenotype. The statistical solution is a device that rules out the case where all the individuals would be of the undesired type (3/4). The procedure is similar to that, when we wish to determine the critical population size with a segregation ratio of 15:1 at 0. Similar calculations are useful for calculating the minimal population size required for the recovery of a mutant individual after mutagenic treatment if we know (or guess) the induced mutation rate. Critical Value: the critical value must be exceeded to reject the null hypothesis in a statistical test. Criticism of Genetics: the criticism of genetics essentially shares the same elements as those of other scientific fields. In most cases where genetics is criticized, the motivation to do so can be attributed largely to perverse political systems. Criss-cross inheritance 440 Crk C traits on the basis of preimplantation screening, etc. Some of the critiques argue that science cannot be left to scientists and the general public must be vigilant and reserve the decision-making for itself. The problem with this view is that how can the layperson make decisions without being fully familiar with a particular field of science. A solution appears to be to increase the continuous education on the progress of science.
Smut: Infection of grasses by basidiomycete fungi medicine 369 generic meldonium 250mg fast delivery, causing black carbon-like transformation of the inflorescence (by Ustilago moroccanoil oil treatment buy 500mg meldonium mastercard, loose smut) or seed tissues (by Tilletia symptoms anxiety discount 250 mg meldonium free shipping, covered smut) medications that cause hair loss proven meldonium 500 mg. S 1834 Snail Snail: A family of zinc-finger transcription factors and a negative regulator of E-cadherin symptoms whooping cough generic meldonium 500 mg visa. Snakes: Reptiles represented by a large number of cosmopolitan species of diverse sizes up to 30 ft in length medicine research buy generic meldonium 500mg. Generally, they do not have legs, except some vestigial remnants in a few species. Their heat-sensory organs are located between the eyes and the nostrils, are highly sensitive, and are used to detect potential prey. Fertilization is internal but the eggs are laid in the environment, although in some species the eggs hatch within the female body. Knowledge of the physiological/molecular nature of these proteins has evolutionary interest and is important because of its therapeutic relevance. Snake Venom Phosphodiesterase: Snake venom phosphodiesterase releases 5-nucleotides from the 3 end of nucleic acids. The name has been attributed to surgical wire tools, by which polyps and projections are removed. This is a ubiquitous enzyme family involved in carbohydrate and lipid metabolism, phosphorylation of transcription factors, regulating stress responses in plants, etc. In order to determine their significance for a disease, their location within the haplotype requires mapping (see. However, when many special cases of the same disease are analyzed, the significance of the base substitutions may be statistically or even causally determined (see. They are apparently involved in splicing and alternative splicing (Kishore S, Stamm S 2006 Science 311:230). Snowdrift Game: One of the theories of evolutionary population dynamics and natural selection. An oversimplified analogy for the principle is that of drivers trapped on either side of a snowdrift. The drivers can either cooperate and both start clearing the road from opposite sides or one of them fails to work (defects). Many anthropologists, sociologists, and ethicists rejected social darwinism and portend that it is an attempt to justify inequalities, harsh competition without adherence to ethics, aggression, imperialism, racism, and unbridled capitalism as necessities for the survival of the fittest. Social darwinism of the 19th century is no longer accepted in the developed world. Social Engineering: the Utopian idea that the genetic determination of an individual is unimportant in defining the abilities and their realization but education, welfare, medical service, etc. Therefore, the state and its institutions must actively control human life from cradle to death. However, even though the importance of compassion, education, caring, and multiple social safety nets are indispensable in a modern society, the significance of individuality cannot be ignored. Social Insects: Insects like bees, wasps, ants, and termites that live in a colony and generally divide various tasks among different castes, such as workers (soldiers), queen, and drones. The major differences between the queen and the workers is that the queens have predominantly 9hydroxy-(E)2-decanoic acid and 9-keto-(E)2-decanoic acid in their mandibular glands. The workers and soldiers have ovaries and under certain circumstances (especially the soldiers) may produce haploid eggs. Cuticular hydrocarbons may regulate sex expression and convert workers into egg-laying females (gamergate), although usually smaller in size. Such a change in some groups may take place by physical contact of individuals transmitting the hydrocarbon molecules. Recently, the status of soldiers has been questioned as being genetically equivalent with the workers. In the fire ant Wasmannia auropunctata, a widely distributed species, sex determination is unique. The males are derived from unfertilized eggs containing only the paternal genome (the maternal genome is eliminated from the diploid eggs). Therefore, the male and female genomes are completely separated (Fournier D et al 2005 Nature [Lond] 435:1230). Social Selection: Social selection is not based on Darwinian fitness but on the social status of the individual carrying the trait. A particular Ychromosome is found in a large region from the Pacific to the Caspian Sea where the Mongols of Genghis Khan ruled. Thus, the rapid spread of this chromosome may be due to the social privileges of the carriers. Preimplantation selection of the sex of human offspring is also called social selection. Its purpose can be the avoidance of defective children caused by chromosomal anomalies and hereditary disease. Sociobiology: the study of the biology and behavior of social insects and other animal communities. Sociogenomics: Sociogenics studies the genetic and molecular biology of the functions involved in social life. Epigenetics has shown however that some traits are transmitted to the progeny by their acquired status of methylation. Software: A computer program that tells the hardware (the computer) the applications, i. Sog: bone morphogenetic protein Soil Remediation: Soil remediation involves the removal of environmental pollutants from soil and water. It requires sensitive identification of small amounts of toxic and carcinogenic and mutagenic substances, such as arsenic, heavy metals, polycyclic hydrocarbons, etc. Actually two different models have been proposed for the 30 nm solenoid structure of the chromosome sub-fibers although neither of them has been fully and universally confirmed. One has been based on the crystal structure of a four-nucleosome core array lacking the linker histone and the other, far more compact structure, has been derived from the electron microscopic analysis of long nucleosome arrays containing the linker histone. The first model is of the two-start helix type, the second a one-start helix with interdigitated nucleosomes. Solid State Control: Solid state control is exercised by electric or magnetic means in solids. Soma: Body cells distinguished from those of sexual reproduction (germinal cells). Somatic Cell: the majority of the body cells (reproduced by mitosis), including those of the germline but not the products of meiosis, the sex cells (gametes). Somatic cell hybrids contain the nucleus of both cells and in addition all cytoplasmic organelles from both parents, in contrast to the generative hybrids where generally mitochondria and plastids are not transmitted through the male. For the fusion of cultured somatic cells, the use of various special techniques is necessary. Most commonly, protoplasts are used and the fusion medium is: Mouse Tumor Cell Figure S80. It is conceivable that the asynchrony between nuclear and cell divisions are accompanied by chromosomal damage. Also, there is evidence that movement Human Fibroblast Sendai Virus Human cells Mouse cells Fused mouse-human cells Plating Fusion Heterokaryote S Selective Isolation Mouse Chromosomes Retained Human Chromosomes Not All Retained Hat Hybrid Cell Medium Hybrid clone A Clone B Clone C Human chromosoms unique for the clones Figure S81. The fused cell usually retains all mouse chromosomes but the human fibroblast chromosomes may be partially eliminated and in some clones only one or another human chromosome is maintained. The isolation of somatic animal cell hybrids was greatly facilitated by using selective media (see. The fusion of animal cells is promoted by polyethylene glycol, by attenuated Sendai virus, or by calcium salts at higher pH. Immediately after fusion, the somatic cells may become heterokaryotic but eventually the nuclei may also fuse. The availability of fused cells along with loss of one set of chromosomes or partial deletion of chromosomes make possible the localization of many human genes (see. Selective isolation of animal somatic cell hybrids deficient in thymidine kinase and hypoxanthine-guanine phosphoribosyltransferase. The translocation chromosome was exposed to a chromosome-breaking agent that cleaved off segments of various lengths from the end of the translocation. Kucherlapati) Human chromosomes 1 A Hybrid clones B C + + + 2 + + 3 + 4 + 5 6 7 8 S + - + + + - + - - - - - - Figure S83. Chromosome assignment of genes on the basis of incomplete clones of mouse + human cell hybrids. If a gene is expressed uniquely in clone (C) but not in (A) or (B), the locus must be in chromosome 7. The genetic constitution of the retained human chromosome can be also verified by enzyme assays, electrophoretic analysis of the proteins, or immunological tests. For genetic analysis of higher mammals, and particularly in humans, where controlled mating is not feasible, the availability of somatic hybrids has opened a new and very productive approach. If two or more human genes are consistently expressed in a particular chromosome retained, it is a safe conclusion that they are located in the same chromosome. By somatic cell fusion, hybrids can be obtained between taxonomically very distant species. All kinds of animal cells may be fused with each other, and in addition plant and animal cells can also be fused. Some of these exotic hybrids may have, however, difficulties in continuing cell divisions. In about nine animal phyla, the germline is not separated from the somatic line, therefore gametes develop from the somatic cell lineage. Somatic Hybrids: somatic cell fusion, somatic cell hybrids, graft hybrids, microfusion Somatic Hypermutations: Somatic hypermutations generally occur in a region of one to two kilobases around the rearranged V-J regions of the immunoglobulin genes and very rarely extend into the C (constant) sections. The preferred hot spots are purineG-pyrimidine-(A/T) sequences, although not all these sequences are hot spots for mutation. It is not entirely clear what determines the targeting of the hypermutations to the special area but transcriptional enhancers appear to be involved. Hypermutations are limited to the coding strand and occur in a downstream polarity. Somatic hypermutation, along with recombination, is the major source of antibody variation and increases the defense repertory in mammals. However, in generative hybrids, because of the uniparental (female) transmission of the organelles, such analyses are not feasible. Since plant cells generally retain totipotency in culture, the hybrid cells may be regenerated into intact organisms and can be further studied in favorable cases by the methods of classical progeny analysis. Somatic Cell Nuclear Transfer: After the enucleation of oocytes, the nucleus of somatic cells from the same or different animals is transferred into the oocytes and this way the donor cell or individual is cloned. This procedure was successful initially for sheep; successful procedures for mice, cows, goats, pigs, rabbits, mule, horse, rats, and dogs followed. Eventually, the oocytes with a new donated diploid nucleus is transferred into the oviduct of a female, which carries the embryo to term. Applying such techniques to human cells is restricted or prohibited in many countries. This procedure for testing mutability is particularly effective if multiple-marker heterozygotes are treated. It is not inherited to generative progeny unless it occurs or expands also to the germline. It has been successfully used for studies of mutation in the stamen hairs of the plant Tradescantia. Recessive mutations are detectable for X-linked genes in hemizygous cells such as those of the male. The procedure is effective if it is directed toward loci with selectable products. The frequency of mutation may be affected by age, and various environmental factors and these can be analyzed. Somatic Pairing: Generally, only the meiotic chromosomes pair during prophase (possibly late interphase), but in some tissues, such as the salivary glands, the chromosomes are always tightly associated. Also, mitotic association of the chromosomes is a requisite for mitotic (somatic) crossing over in a few organisms where this phenomenon has been analyzed. Somatic Recombination: mitotic crossing over Somatic Reduction: the reduction of chromosome numbers during mitosis in polyploids. In association with other binding proteins, it is involved in the stimulation of several cellular functions. Somatoplastic Sterility: In certain plant hybrids, the nucellus may show excessive growth, and chokes the embryo to death. The embryo can be rescued if excised early and transferred to in vitro culture media. The somatostatin gene has been mapped to human chromosome 3q28 and to mouse chromosome 16. They are sevenpass-transmembrane proteins frequently bound to G-proteins and distributed all over the body, at particularly high levels in the stomach, brain, and kidney. Somatotroph: the growth hormone-secreting cell in the adenohypophysis (in the anterior lobe of the pituitary of the brain). S Sortase 1845 Actually, there are three human growth hormones, all coded at chromosome 17q23-q24. The placental lactogen protein is an even more effective growth hormone, also located nearby, and it is highly homologous. The human growth hormone gene is transcribed only in the pituitary, whereas the homologs are expressed in the placental tissues. Transformation of mice with rat growth hormone genes increased body size substantially. Somites: Somites are paired mesoderm blocks along the longitudinal axis (notochord) of an embryo that give rise to the vertebral column and other segmented structures. The development of the somites is controlled mainly by the Notch Wnt family and associated proteins.
Diseases
The accumulation of galactoside-sulfate-cerebrosides in the plasma membrane and particularly in the neural tissues (myelin) causes a progressive and fatal degeneration in the peripheral nerves medications zyprexa generic meldonium 500 mg free shipping, liver and kidneys medicine 74 generic meldonium 250mg with visa. As a consequence failure of muscular coordination (ataxia) treatment jammed finger generic meldonium 250mg otc, involuntary partial paralysis medicine 4 you pharma pvt ltd generic meldonium 250mg without a prescription, hearing and visual defects as well as lack of normal brain function arise after 18 to 24 months of age and usually causes death in early childhood medicine escitalopram order meldonium 250 mg. In the juvenile form of the disease the symptoms appear between age 4 and 10 years treatment room purchase meldonium 500mg on-line. There is also an adult type of the disease with an onset after age 16 and involves schizophrenic symptoms. The mutations involve either a substitution of tryptophan at amino acid residue 193, or at threonine 391 by serine or a defect at the splice donor site at the border of exon 2. The reduced activity of the enzyme can be identified also in cultured skin fibroblasts of heterozygotes and prenatally in cultured amniotic fluid cells of fetuses. Metacyclic Trypanosoma: Parasitic eukaryote that lives in the salivary gland of insects, which spread sleeping sickness. Trypanosoma Metacyclogenesis: the differentiation of the promastigote of Leishmania into a highly infective form in the sandfly. Such studies yield valuable information on evolution, new genes, new functions and new antibiotics. Such a duplex may have advantage for some applications because of higher thermal stability or for the construction of molecular magnets. Metalloproteinases (metalloproteases): Cell surface endopeptidase enzymes mediating the degradation of the extracellular matrix, cartilage formation, the release of tumor necrosis factor, a cytokine involved in inflammatory reactions, in embryogenesis, and cell migration. Cancer tissues are associated with increased protease activities and it is supposed that these activities facilitate the bursting out of the tumor from the normal cell milieu and increase angiogenesis. Metagenomics: the analysis of the genomes of groups of organisms in samples from the environment, including special environmental locations, such as deep sea, hospital waste, acid mine water, and 1192 Metallothionein 11p15) is involved in tissue healing and remodeling. This promoter is very useful for experimental purposes because structural genes attached to it can be turned on and off by regulating the amount of heavy metal in the drinking water of the transgenic animals. In chemistry it is rarely used for a type of structural isomerism when different radicals of the same type are attached to the same polyvalent element and give rise to compounds possessing identical formulas. Metamorphosis: the distinct change from one developmental stage to another, such as from larva to adult or from tadpole to toad. Drosophila Metanomics: the use of gas chromatography and mass spectrometry to trace metabolic changes upon mutation or environmental changes. In meiosis I the bivalent chromosomes may be associated at their ends if chiasmata had taken place during pro-phase. The ring bivalents indicate crossing over between both arms whereas rod bivalents are visible when crossing over was limited to only one of the two arms. Sullivan, Department of Cell Biology, the Scripps Research Institute, San Diego, California and Don W. Cleveland, Ludwig Institute for Cancer Research, University of California, San Diego, California. Metameric insect Metaphase Arrest: Can occur if toxic agents or two separate kinetochores joined by translocation block the nuclear division. Homologous recombination does not lead to metaphase arrest indicating kinetochore tension may be responsible for the event. Metaplasia: One cell type gives rise to another and in the tissue the two may be adjacent. Metastable: A potentially transitory state; it can change to more or less stable form. Metastasis: the spread of cancer cells through the blood stream and thus establishing new foci of malignancy in any part of the body although. Metastasis has been attributed to epigenetic changes and/or mutation during cancer progression. Three membrane-anchored proteases, type-1, type-2, and type-3 metalloproteinases, independently confer cancer cells with the ability to proteolytically open the basement membrane scaffolding, initiate the assembly of invasive pseudopodia, and propagate transmigration (Hotary K et al 2006 Genes Dev 20:2673). The invasiveness of cancer cells requires an active state of the integrin system, cell surface gelatinases (collagenases, proteases) so they could penetrate the extracellular matrix of the target cells. On the cell surface actually precursors of the gelatinases are found that are proteolytically activated by metalloproteinases. These compounds were highly selective in their effect on tumor cells compared to normal cells (see. It seems that these chemokine receptors and chemokines play important role in metastasis. The direction of invasiveness may depend on the organs/ tissues where these receptors are expressed. Platelet-derived lysophosphatidic acid promotes the progression of breast and ovarian cancer metastasis to bone. Techniques have been designed for the identification of genes, which control/suppress metastasis. In a forward mutation test of mice, disulfide isomerases (thiol isomerases), which catalyze disulfide bond formation, reduction and isomerization, were found to mediate metastasis. Metastasis of melanoma cells may be initiated by an increase in the expression of fibronectin, RhoC and thymosin 4 as visualized by microarray hybridization. Microarray hybridization of primary tumor tissue transcripts may permit the prognostication of tumor progression and patient survival. Metatarsus: the middle bones beyond the ankle but preceding the toes in a human foot. In insects the basal part of the foreleg distal to the tibia but proximal to the tarsal segments and the claw (see. Metatarsus Metaxenia: A physiological modification of maternal tissues of the fruit in plants by the genetically different embryo. Methacrylateaciduria: -hydroxyl-isobutyryl CoA deacylase deficiency-involving the catabolism of valine-leads to urinary excretion of cysteine and cysteinamine conjugates of methacrylic acid, and to teratogenic effects. Methotrexate 1195 Methanogenesis: It takes place by decay of various types of organic material brought about by Archaebacteria and other microorganisms (see. Burning fossil fuels, wetlands, landfill fermentation, livestock manure, termites, etc. More recently a very substantial role in methane production is attributed to the vegetation (Nature [Lond] 2006 442:730). Methionine adenosyl transferase catalyzes the biosynthesis of Sadenosylmethionine a major methyl donor in the cell. Mental retardation, convulsions, diarrhea, respiratory problems and white eye accompany the condition. It is an inhibitor of thymidylate synthase, glycinamide ribonucleotide transformylase and 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase. Because of its multiple metabolic effects, response to it may vary according to the genetic constitution of the patient. A mutant dehydrofolate reductase may improve the resistance to methotrexate and may be advantageous for cancer chemotherapy. Sphagnum moss Methemoglobin (ferrihemoglobin, hemiglobin): A hemoglobin with the ferroheme oxidized to ferriheme and has impaired reversible oxygen binding ability. Mutation and certain chemicals (ferricyanide, methylene blue, nitrites) may increase the normally slow oxidation of hemoglobin. Reduction of methemoglobin may be accomplished either through the Embden-Meyerhof pathway or through the oxidative glycolytic pathway (pentose phosphate pathway). As a consequence, lifelong cyanosis (bluish discoloration of the skin and mucous membranes) results following the accumulation of reduced hemoglobin in the blood. This anomaly may be corrected with the reducing agents, methylene blue or ascorbic acid. The most direct cause of hypermethioninemia is an autosomal recessive defect in methionine adenosyltransferase. If the protein binds to a specific guanine site(s), that base will not be methylated. Methylation of other bases thymine (= 5-methyluracil), adenine and guanine may also occur in prokaryotes. In bacteria, the expression of methylated genes may be reduced by a factor of 1000 but in mammals, the reduction may be of six orders of magnitude. The double mutants (a, b) cannot develop beyond gastrulation (Li E et al 1992 Cell 69:915). Dnmt1 is incapable for de novo methylation; its role is maintenance methylation of the unmethylated strand generated by replication across the methylated strand in the double helix. In some fungi (Ascobolus, Neurospora) peptide chain elongation may also be inhibited. Methylation by Dnmt1 may affect also histone deacetylation and chromatin remodeling. About one-third of the expressed genes contain methylated bases within transcribed areas contrary to expectations. Only 5% of the promoters display methylation and frequently show tissuespecific expression. Moderately transcribed genes of Arabidopsis are most likely to be methylated, whereas genes at either extreme are least likely. In turn, transcription is influenced by methylation: short methylated genes are poorly expressed, and loss of methylation in the body of a gene leads to enhanced transcription (Zilberman D et al 2007 Nature Genet 39:61). Demethylation of tumor suppressor genes (by antisense technology) restores their suppressor function whereas methylation of the same genes silences them (Robert M-F et al 2003 Nature Genet 33:61). It seems that the genome of higher eukaryotes, including humans, includes 35% or more active or silent transposable elements. Actually most of the methylated cytosines in mammals are in the parasitic transposable elements. In the small invertebrate chordate Ciona intestinalis non-methylated transposons and normally methylated genomic sequences were detected (Simmen et al 1999 Science 283:1164). Although this hypothesis is in agreement with many observations, it does not seem to be of general validity, particularly for the methylation of plant transposable elements. The epigenetic state of methylation can be transferred in the ascomycete, Ascobolus by a mechanism resembling or related to recombination. After fertilization, the methyl moieties are generally removed from the CpGs and an unmethylated state is maintained through blastula stage. Some of the genes involved in tumorigenesis display an increased methylation on aging. Housekeeping genes stay unmethylated whereas the methylation of tissue-specific genes varies by tissues. The maternal genomes in haploid and diploid gynogenetic one-cell mammalian embryos are always methylated. The paternal genomes in haploid or diploid androgenetic embryos are de-methylated. Triploid digynic embryos show two methylated maternal and one de-methylated paternal chromosome set. In the mammals, the active X chromosome displays more than two times as much allele-specific methylation as the inactive X. This methylation is concentrated at gene bodies, affecting multiple neighboring CpGs. A methylation-demethylation program results in active X-specific hypomethylation at gene promoters and hypermethylation at gene bodies (Hellman A, Chess A 2007 Science 315:1141). Methyltransferase enzymes comprising enhanced zincfinger arrays coupled to methyltransferase mutants are functionally dominated by their zinc-finger component. Changes in methylation are apparently not required for the regulation of development of zebrafish. In the embryonic tissues of mice CpA and CpT are also methylated to some extent not just CpG. Methylation of the promoter may interfere with the attachment of the transcription factors. The silencing effect of methylation may be associated with the simultaneous deacetylation of the nucleosomes. Methylation of Proteins: Reversible post-translational alteration involved in regulation most frequently at arginine and lysine sites. Other isoschizomer pairs with one methylation-sensitive restriction enzyme can be used similarly. Methylator: It simultaneously methylates several sites in different cancer suppressor genes. As a consequence of this autosomal recessive condition, muscle defects, and in some cases urinary overexcretion of 3-methylcrotonyl glycine and 3-hydroxyisovaleric acids occurs. Some patients respond favorably to biotin because this vitamin is a cofactor of the enzyme. Deamination of 5-methylcytosine at CpG sites into thymidine is one of the most common causes of disease and accounts for 20% of all human point mutations (see. Methylimidazole: pyrrole Methyljasmonate: the fragrance of jasmine and rosemary plants; it is a proteinase inhibitor. A third type of methylmalonic aciduria is due to a defect in the enzyme epimerase (racemase) that converts D-methylmalonylCoA to the L form. In these disorders methylmalonic acid and glycine may accumulate in the body fluids, and the affected individuals may show serious (growth and mental retardation, acidosis [keto acids in the blood]) or almost no adverse effects.
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