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Section: Limitation and future directions. Chemogenetics and usage of DREADDs have allowed researchers to advance in biomedical research areas including many neurodegenerative and psychiatric conditions. Chemogenetics have been used in these fields to induce specific and reversible brain lesions and therefore, study sp... | Wikipedia - Chemogenetics - Limitation and future directions | 211 | 1,059 | null |
Article: Chi site. A Chi site or Chi sequence is a short stretch of DNA in the genome of a bacterium near which homologous recombination is more likely to occur than on average across the genome. Chi sites serve as stimulators of DNA double-strand break repair in bacteria, which can arise from radiation or chemical tre... | Wikipedia - Chi site - Summary | 313 | 1,332 | null |
Upon encountering the Chi sequence as it unwinds DNA, RecBCD cuts the DNA a few nucleotides to the 3’ side of Chi, within the important sequences noted above; depending on the reaction conditions, this cut is either a simple nick on the 3'-ended strand or the change of nuclease activity from cutting the 3’-ended strand... | Wikipedia - Chi site - Summary | 350 | 1,497 | null |
Article: Chiasma (genetics). In genetics, a chiasma (pl.: chiasmata) is the point of contact, the physical link, between two (non-sister) chromatids belonging to homologous chromosomes. At a given chiasma, an exchange of genetic material can occur between both chromatids, what is called a chromosomal crossover, but thi... | Wikipedia - Chiasma (genetics) - Summary | 309 | 1,276 | null |
The chiasmata become visible during the diplotene stage of prophase I of meiosis, but the actual "crossing-overs" of genetic material are thought to occur during the previous pachytene stage. Sister chromatids also form chiasmata between each other (also known as a chi structure), but because their genetic material is ... | Wikipedia - Chiasma (genetics) - Summary | 343 | 1,491 | null |
Article: Chimera (molecular biology). In molecular biology, and more importantly high-throughput DNA sequencing, a chimera is a single DNA sequence originating when multiple transcripts or DNA sequences get joined. Chimeras can be considered artifacts and be filtered out from the data during processing to prevent spuri... | Wikipedia - Chimera (molecular biology) - Summary | 203 | 1,007 | null |
Section: Description > PCR chimera. A chimera can also be an artifact of PCR amplification. It occurs when the extension of an amplicon is aborted, and the aborted product functions as a primer in the next PCR cycle. The aborted product anneals to the wrong template and continues to extend, thereby synthesizing a singl... | Wikipedia - Chimera (molecular biology) - Description > PCR chimera | 284 | 1,287 | null |
Section: Mechanics of Codon Reassignment > Normal Codon Behavior. Proteins are essential to life, preforming many necessary cellular functions. Cells construct proteins with amino acids using DNA instructions. Typically, DNA is transcribed into messenger RNA (mRNA) and the mRNA is translated into a sequence of amino ac... | Wikipedia - Codon reassignment - Mechanics of Codon Reassignment > Normal Codon Behavior | 230 | 1,128 | null |
Section: Examples of Codon Reassignment > Amino acid deficiencies. In bacteria and yeast, codon reassignment can be caused by a shortage of required amino acids. Instead of halting protein production all together, tRNA molecules select another amino acid to add to the amino acid chain. This amino acid may have similar ... | Wikipedia - Codon reassignment - Examples of Codon Reassignment > Amino acid deficiencies | 258 | 1,229 | null |
Section: Implications of Codon Reassignment > Potential Uses of Codon Reassignment. Artificial, synthetic, unnatural, or non-proteinogenic amino acids are used in research to help understand the construction and functionality of proteins. These artificial amino acids are also used in some medications. Researchers norma... | Wikipedia - Codon reassignment - Implications of Codon Reassignment > Potential Uses of Codon Reassignment | 243 | 1,334 | null |
Article: Coefficient of coincidence. In genetics, the coefficient of coincidence (c.o.c.) is a measure of interference in the formation of chromosomal crossovers during meiosis. It is generally the case that, if there is a crossover at one spot on a chromosome, this decreases the likelihood of a crossover in a nearby s... | Wikipedia - Coefficient of coincidence - Summary | 258 | 1,193 | null |
Section: Worked example. Drosophila females of genotype a+a b+b c+c were crossed with males of genotype aa bb cc. This led to 1000 progeny of the following phenotypes: a+b+c+: 244 (parental genotype, shows no recombination) a+b+c: 81 (recombinant between B and C) a+bc+: 23 (double recombinant) a+bc: 152 (recombinant be... | Wikipedia - Coefficient of coincidence - Worked example | 322 | 1,039 | null |
Section: High negative interference. When three genetic markers, a, b and c, are all nearby (e.g. within the same gene) the coefficient of coincidence (calculated as in the above example) is generally found to be significantly greater than 1. This implies that any individual recombination event tends to be more closely... | Wikipedia - Coefficient of coincidence - High negative interference | 155 | 725 | null |
Section: Genetic determinism. It is a popular misconception that all patterns of an animal's behaviour, and more generally its phenotype, are rigidly determined by its genes. Although many examples of animals exist that display certain well-defined behaviour that is genetically programmed, these examples cannot be extr... | Wikipedia - Common misunderstandings of genetics - Genetic determinism | 223 | 1,196 | null |
Section: A gene for X. In the early years of genetics it was suggested that there might be "a gene for" a wide range of particular characteristics. This was partly because the examples studied from Mendel onwards inevitably focused on genes whose effects could be readily identified; partly that it was easier to teach s... | Wikipedia - Common misunderstandings of genetics - A gene for X | 194 | 964 | null |
Section: Genes as a blueprint. It is widely believed that genes provide a "blueprint" for the body in much the same way that architectural or mechanical engineering blueprints describe buildings or machines. At a superficial level, genes and conventional blueprints share the common property of being low dimensional (ge... | Wikipedia - Common misunderstandings of genetics - Genes as a blueprint | 339 | 1,799 | null |
Section: Genes as words. It is popularly supposed that a gene is "a linear sequence of nucleotides along a segment of DNA that provides the coded instructions for synthesis of RNA" and even some current medical dictionaries define a gene as "a hereditary unit that occupies a specific location on a chromosome, determine... | Wikipedia - Common misunderstandings of genetics - Genes as words | 194 | 982 | null |
Section: Ancestry and ethnicity. Genetic ancestry tests advertised by companies such as 23andMe and AncestryDNA do not actually reveal a person's geographical ancestral origins or determine their race and ethnicity. They estimate the genetic ancestry and population group of a certain person. They compare a person's DNA... | Wikipedia - Common misunderstandings of genetics - Ancestry and ethnicity | 299 | 1,666 | null |
Article: Compound heterozygosity. In medical genetics, compound heterozygosity is the condition of having two or more heterogeneous recessive alleles at a particular locus that can cause genetic disease in a heterozygous state; that is, an organism is a compound heterozygote when it has two recessive alleles for the sa... | Wikipedia - Compound heterozygosity - Summary | 336 | 1,595 | null |
Section: Cause. Compound heterozygosity is one of the causes of variation in genetic disease. The diagnosis and nomenclature for such disorders sometimes reflects history, because most diseases were first observed and classified based on biochemistry and pathophysiology before genetic diagnosis was available. Some gene... | Wikipedia - Compound heterozygosity - Cause | 330 | 1,700 | null |
For some genetic diseases, environmental cofactors are an important determinant of variation and outcome. In the case of hemochromatosis, penetrance is incomplete, even for the classic HFE mutation, and is affected by gender, diet, and behaviors such as alcohol consumption. Compound heterozygotes are often observed onl... | Wikipedia - Compound heterozygosity - Cause | 319 | 1,537 | null |
Section: Examples. Phenylketonuria. Because phenylketonuria was the first genetic disorder for which mass post-natal genetic screening was available, beginning in the early 1960s, atypical cases were detected almost immediately. Molecular analysis of the genome was not yet possible, but protein sequencing revealed case... | Wikipedia - Compound heterozygosity - Examples | 290 | 1,321 | null |
Section: Generating congenic strains. Congenic strains are generated in the laboratory by mating two inbred strains (usually rats or mice), and back-crossing the descendants 5–10 generations with one of the original strains, known as the recipient strain. Typically, selection for either phenotype or genotype is perform... | Wikipedia - Congenic - Generating congenic strains | 285 | 1,347 | null |
Article: Copy number analysis. Copy number analysis is the process of analyzing data produced by a test for DNA copy number variation in an organism's sample. One application of such analysis is the detection of chromosomal copy number variation that may cause or may increase risks of various critical disorders. Copy n... | Wikipedia - Copy number analysis - Summary | 347 | 1,791 | null |
Section: Example. In one study of natural transformation, investigators isolated B. subtilis bacteria with two mutations—trpC2 and hisB2—that made them Trp- , His- auxotrophs. These double auxotrophs served as the recipient in the study, wild-type cells (Trp+ , His+ ) were the donors. In this study, the numbers of Trp+... | Wikipedia - Cotransformation - Example | 158 | 611 | null |
Article: Countergradient variation. Countergradient variation is a type of phenotypic plasticity that occurs when the phenotypic variation determined by a biological population's genetic components opposes the phenotypic variation caused by an environmental gradient. This can cause different populations of the same org... | Wikipedia - Countergradient variation - Summary | 341 | 1,942 | null |
Section: History. Countergradient variation, originally termed "contra-gradient variation", was coined by Richard Levins in his 1968 book Evolution in Changing Environments. Levins first used the term when describing patterns of body size across an altitudinal gradient in populations of Drosophila, and since then many ... | Wikipedia - Countergradient variation - History | 218 | 1,087 | null |
Section: Mechanisms. Countergradient variation is the opposite of cogradient variation, in which the environmental effect on the phenotype enhances the genetic effect on the phenotype. One common way to test for both of these patterns is with transplant experiments. By bringing the two populations to the same environme... | Wikipedia - Countergradient variation - Mechanisms | 324 | 1,764 | null |
Section: Ecological relevance. Populations that inhabit high latitudes experience shorter growing seasons than those that inhabit low latitudes due to the differences in seasonality. Because of this, it is thought that countergradient variation of growth is a means to compensate for the short amount of time juveniles h... | Wikipedia - Countergradient variation - Ecological relevance | 337 | 1,865 | null |
Article: CRT (genetics). CRT is the gene cluster responsible for the biosynthesis of carotenoids. Those genes are found in eubacteria, in algae and are cryptic in Streptomyces griseus. Carotenoid synthesis is probably present in the common ancestor of Bacteria and Archaea; the phytoene synthase gene crtB is universal a... | Wikipedia - CRT (genetics) - Summary | 164 | 687 | null |
Section: Role of CRT genes in carotenoid biosynthesis. The CRT gene cluster consists of twenty-five genes such as crtA, crtB, crtC, crtD, crtE, crtF, crtG, crtH, crtI, crtO, crtP, crtR, crtT, crtU, crtV, and crtY, crtZ. These genes play a role in varying stages of the Astaxanthin biosynthesis and Carotenoid biosynthesi... | Wikipedia - CRT (genetics) - Role of CRT genes in carotenoid biosynthesis | 331 | 1,033 | null |
Section: Role of CRT genes in carotenoid biosynthesis > Other. Zeaxanthin can be further processed to obtain zeaxanthin-diglucoside by Zeaxanthin glucosyl transferase (crtX). Echinenone is obtained from β -carotene through the catalyzing enzyme β-C-4-oxygenase/β-carotene ketolase (crtO). CrtO, also known as bkt2 in Chl... | Wikipedia - CRT (genetics) - Role of CRT genes in carotenoid biosynthesis > Other | 304 | 912 | null |
Section: Phylogeny. Previous studies have indicated through phylogenetic analysis that evolutionary patterns of crt genes are characterized by horizontal gene transfer and gene duplication events. Horizontal gene transfer has been hypothesized to have occurred between cyanobacteria and Chlorophyta, as similarities in t... | Wikipedia - CRT (genetics) - Phylogeny | 327 | 1,435 | null |
Article: Cultural hitchhiking. Cultural hitchhiking is a hypothesized gene-culture coevolutionary process through which cultural selection, sexual selection based on cultural preference, limits the diversity at genetically neutral loci being transmitted in parallel to selective cultural traits. The process is thought t... | Wikipedia - Cultural hitchhiking - Summary | 260 | 1,475 | null |
Section: In whales. The process was initially proposed by Whitehead in a 1998 paper as an explanation for the low genetic diversity in matrilineal whale species. In these communities, female individuals remain grouped together with their mothers and other female relatives. They appear to select mates from outside their... | Wikipedia - Cultural hitchhiking - In whales | 170 | 1,028 | null |
Section: In dolphins. In 2014 a team of biologists from the University of South Wales attributed a remarkable geographic distribution of mitochondrial haplotypes among adjacent populations of bottlenose dolphins in a bay in Western Australia to cultural hitchhiking. The researchers found Whitehead’s hypothesis that sel... | Wikipedia - Cultural hitchhiking - In dolphins | 273 | 1,480 | null |
Section: In early humans. Cultural hitchhiking has been proposed as an explanation for a widely inferred and abrupt Y-chromosome population bottleneck across several Old World (Africa, Europe, Asia) populations around 4000-6000 BC. This bottleneck is thought to suggest a significant decline in the effective male popula... | Wikipedia - Cultural hitchhiking - In early humans | 290 | 1,514 | null |
Article: Cytodeme. The Cytodeme is the total assembly of organisms that use an identical suite of chromosomes to carry their genes. The term was first printed in the 1950s in a book by Heslop-Harrison. Discussing the Deme Terminology - he continued "cytodeme, a population differing in some distinctive cytological featu... | Wikipedia - Cytodeme - Summary | 313 | 1,464 | null |
Section: Significance. The current surge of interest in cytodemes stems from the realisation that membership of the cytodeme is not necessarily restricted to the members of one species: frequently two or more species are in fact of the same cytodeme. Although fully intercompatible and yielding fertile hybrids when they... | Wikipedia - Cytodeme - Significance | 327 | 1,578 | null |
It is more likely, though, that the cytodeme arose first complete with its suite of chromosomes and breeding patterns all intact and then, remaining constant in its fundamentals, it diversified into species sometimes so different as to merit generic distinction. Thus, in what may be termed the cytodeme adjunct to Darwi... | Wikipedia - Cytodeme - Significance | 300 | 1,419 | null |
Section: Description. Cytotaxonomy is a branch of taxonomy that uses the characteristics of cellular structures to classify organisms. In cytotaxonomy, the chromosomal configuration of an organism is the most widely used parameter to infer the relationship between two organisms. The inference of species relationships i... | Wikipedia - Cytotaxonomy - Description | 326 | 1,674 | null |
Section: Definition. De novo domestication refers to the process by which wild species are intentionally transformed into domesticated varieties. The majority of domesticated species has been under domestication for millenia, with the first animal, the dog, having been under domestication for between 40,000-30,000 year... | Wikipedia - De novo domestication - Definition | 350 | 1,906 | null |
Section: In plants > Redomestication. Another use for de novo domestication is the redomestication of wild relatives of domesticated crops. Through millennia under selection, most domesticated crops have undergone many genetic bottlenecks, drastically reducing their genetic diversity, and thus the ability to breed in n... | Wikipedia - De novo domestication - In plants > Redomestication | 181 | 982 | null |
Article: Deme (biology). In biology, a deme, in the strict sense, is a group of individuals that belong to the same taxonomic group. However, when biologists, and especially ecologists, use the term ‘deme’ they usually refer to it as the definition of a gamodeme: a local group of individuals (from the same taxon) that ... | Wikipedia - Deme (biology) - Summary | 183 | 813 | null |
Section: Local adaptation. A population of a species usually has multiple demes. Environments between these demes can differ. Demes could, therefore, become locally adapted to their environment. A good example of this is the Adaptive Deme Formation (ADF) hypothesis in insects. The ADF hypothesis states that herbivorous... | Wikipedia - Deme (biology) - Local adaptation | 227 | 1,159 | null |
Section: Speciation and demes. Speciation could occur at the level of demes. When a deme gets geographically isolated from other demes of the same species, gene-flow between these demes will stop which could lead to speciation after a long time. This is called allopatric speciation and is generally a slow process. On t... | Wikipedia - Deme (biology) - Speciation and demes | 345 | 1,562 | null |
Article: Dermatoglyphics. Dermatoglyphics (from Ancient Greek derma, "skin", and glyph, "carving") is the scientific study of fingerprints, lines, mounts and shapes of hands, as distinct from the superficially similar pseudoscience of palmistry. Dermatoglyphics also refers to the making of naturally occurring ridges on... | Wikipedia - Dermatoglyphics - Summary | 163 | 752 | null |
Section: History. 1823 marks the beginning of the scientific study of papillary ridges of the hands and feet, with the work of Jan Evangelista Purkyně. By 1858, Sir William Herschel, 2nd Baronet, while in India, became the first European to realize the value of fingerprints for identification. Sir Francis Galton conduc... | Wikipedia - Dermatoglyphics - History | 304 | 1,470 | null |
Section: Dermatoglyphics and genetic conditions. Dermatoglyphics, when correlated with genetic abnormalities, aids in the diagnosis of congenital malformations at birth or soon after. Klinefelter syndrome: excess of arches on digit 1, more frequent ulnar loops on digit 2, overall fewer whorls, lower ridge counts for lo... | Wikipedia - Dermatoglyphics - Dermatoglyphics and genetic conditions | 308 | 1,320 | null |
Trisomy 18 (Edward's syndrome): 6–10 arches on fingertips and single transverse palmar creases in 30% of patients. Trisomy 21 (Down syndrome): people with Down syndrome have a fingerprint pattern with mainly ulnar loops, and a distinct angle between the triradia a, t, and d (the 'adt angle'). Other differences include ... | Wikipedia - Dermatoglyphics - Dermatoglyphics and genetic conditions | 288 | 1,301 | null |
Article: Developmental homeostasis. Developmental homeostasis is a process in which animals develop more or less normally, despite defective genes and deficient environments. It is an organism's ability to overcome certain circumstances in order to develop normally. This can be a circumstance that interferes with eithe... | Wikipedia - Developmental homeostasis - Summary | 341 | 1,831 | null |
Section: Developmental homeostasis: isolation of monkeys > Effects of social isolation in rhesus monkeys. The effects of developmental homeostasis were demonstrated in an experiment conducted in 1966 by Margaret and Harry Harlow. They wanted to test what the consequences of infant rhesus monkeys would be from being sep... | Wikipedia - Developmental homeostasis - Developmental homeostasis: isolation of monkeys > Effects of social isolation in rhesus monkeys | 324 | 1,777 | null |
The monkeys underwent little if any sexual posturing or reproduction in their lifetime. To test how much social experience is necessary or needed in normal development, the Harlows performed another experiment where they isolated young rhesus monkeys by limiting the interaction time with other monkeys. They gave them f... | Wikipedia - Developmental homeostasis - Developmental homeostasis: isolation of monkeys > Effects of social isolation in rhesus monkeys | 338 | 1,908 | null |
Section: Developmental homeostasis in symmetry and asymmetry > Symmetry in facial features. The symmetry in the facial features of humans could be found as appealing to men and women. This could be due to the ability to find prospective mates in responding positively to either body or facial symmetry. This could be bec... | Wikipedia - Developmental homeostasis - Developmental homeostasis in symmetry and asymmetry > Symmetry in facial features | 259 | 1,403 | null |
Section: Developmental homeostasis in symmetry and asymmetry > Reproductive advantages. Developmental homeostasis is present not only in humans, but in animals as well. The choosing of symmetrical features over asymmetrical features have been observed in birds, lizards, Araneae, and even insects. For example, barn swal... | Wikipedia - Developmental homeostasis - Developmental homeostasis in symmetry and asymmetry > Reproductive advantages | 257 | 1,324 | null |
Article: Diallel cross. A diallel cross is a mating scheme used by plant and animal breeders, as well as geneticists, to investigate the genetic underpinnings of quantitative traits. In a full diallel, all parents are crossed to make hybrids in all possible combinations. Variations include half diallels with and withou... | Wikipedia - Diallel cross - Summary | 174 | 879 | null |
Section: In cancer. Multiple studies have discovered abnormalities in distal promoters within cancer cells. For example, an overactive distal promoter located about 1 kilobase away from the MUC5B gene contributes to atypical expression of this gene in gastric cancer cells. Similarly, a few polymorphisms in the RUNX3 di... | Wikipedia - Distal promoter - In cancer | 207 | 921 | null |
Article: Distyly. Distyly is a breeding system in plants that is characterized by two separate flower morphs, where individual plants produce flowers that have either long styles and short stamens (L-morph flowers) or short styles and long stamens (S-morph flowers). However, distyly can refer to any plant that shows so... | Wikipedia - Distyly - Summary | 218 | 958 | null |
Section: Background. The first scientific account of distyly can be found in Stephan Bejthe's Caroli book Clusii Atrebatis Rariorum aliquot stirpium . Bejthe describes the two floral morphs of Primula veris. Charles Darwin popularized distyly with his account of it in his book The Different Forms of Flowers on Plants o... | Wikipedia - Distyly - Background | 249 | 1,069 | null |
Section: Reciprocal herkogamy. Reciprocal herkogamy likely evolved to prevent the pollen of the same flower from landing on its own stigma. This in turn promotes outcrossing. In a study of Primula veris it was found that pin flowers exhibit higher rates of self-pollination and capture more pollen than the thrum morph. ... | Wikipedia - Distyly - Reciprocal herkogamy | 179 | 849 | null |
Section: Models of evolution. There are two main hypothetical models for the order in which the traits of distyly evolved, the 'selfing avoidance model' and the 'pollen transfer model'. The selfing avoidance model suggests self-incompatibility (SI) evolved first, followed by the morphological difference. It was suggest... | Wikipedia - Distyly - Models of evolution | 151 | 781 | null |
Section: Genetic control of distyly. A supergene, called the self-incompatibility (or S-) locus, is responsible for the occurrence of distyly. The S-locus is composed of three tightly linked genes (S-genes) which segregate as a single unit. Traditionally it was hypothesized that one S-gene controls all female aspects o... | Wikipedia - Distyly - Genetic control of distyly | 276 | 1,039 | null |
Section: Genetic control of distyly > The S-locus of Primula. In Primula the S-locus is composed of five genes, CYPT(or CYP734A50), GLOT (or GLOBOSA2), KFBT, PUMT, and CCMT. The supergene evolved in a step-by-step manner, meaning each S-gene duplicated and move to the pre-S-locus independently of the others. Synonymous... | Wikipedia - Distyly - Genetic control of distyly > The S-locus of Primula | 335 | 1,206 | null |
Article: DNase I hypersensitive site. In genetics, DNase I hypersensitive sites (DHSs) are regions of chromatin that are sensitive to cleavage by the DNase I enzyme. In these specific regions of the genome, chromatin has lost its condensed structure, exposing the DNA and making it accessible. This raises the availabili... | Wikipedia - DNase I hypersensitive site - Summary | 187 | 890 | null |
Section: Massive analysis. The ENCODE project proposes to map all of the DHSs in the human genome with the intention of cataloging human regulatory DNA. DHSs mark transcriptionally active regions of the genome, where there will be cellular selectivity. So, they used 125 different human cell types. This way, using the m... | Wikipedia - DNase I hypersensitive site - Massive analysis | 242 | 1,147 | null |
Section: Regulatory DNA tools. The study of DHS profiles combined with other techniques allows analysis of regulatory DNA in humans: Transcription factor: Using the ChIP-Seq technique, the binding sites to DNA in certain transcription factor groups are determined, and the DHS profiles are compared. The results confirm ... | Wikipedia - DNase I hypersensitive site - Regulatory DNA tools | 340 | 1,741 | null |
Using the DHS profiles, were looked for correlations between DHS to identify promoter/enhancer connections. Thus, it was able to create a map of candidate enhancers controlling specific genes. The data obtained were validated with the chromosome conformation capture carbon copy (5C) technique. This technique is based i... | Wikipedia - DNase I hypersensitive site - Regulatory DNA tools | 264 | 1,457 | null |
Section: Domestication islands. In 2007, a study of the genomic DNA differences of wild compared to domesticated species of beans found that there was a large fraction of the genome of the common bean that appears to have been subjected to the effects of selection during domestication. Domestication appears to have aff... | Wikipedia - Domestication islands - Domestication islands | 265 | 1,444 | null |
Article: Domestication syndrome. Domestication syndrome refers to two sets of phenotypic traits that are common to either domesticated plants or domesticated animals. Domesticated animals tend to be smaller and less aggressive than their wild counterparts; they may also have floppy ears, variations to coat color, a sma... | Wikipedia - Domestication syndrome - Summary | 304 | 1,659 | null |
Section: Origin. Charles Darwin's study of The Variation of Animals and Plants Under Domestication in 1868 identified various behavioral, morphological, and physiological traits that are shared by domestic animals, but not by their wild ancestors. These shared traits became known as "the domestication syndrome", a term... | Wikipedia - Domestication syndrome - Origin | 337 | 1,796 | null |
Section: Cause. Many similar traits – both in animals and plants – are produced by orthologs; however, whether this is true for domestication traits or merely for wild forms is less clear. Especially in the case of plant crops, doubt has been cast because some domestication traits have been found to result from unrelat... | Wikipedia - Domestication syndrome - Cause | 312 | 1,604 | null |
Section: In animals. A dog's cranium is 15% smaller than an equally heavy wolf's, and the dog is less aggressive and more playful. Other species pairs show similar differences. Bonobos, like chimpanzees, are a close genetic cousin to humans, but unlike the chimpanzees, bonobos are not aggressive and do not participate ... | Wikipedia - Domestication syndrome - In animals | 332 | 1,585 | null |
Section: In animals > Challenge. The domestication syndrome was reported to have appeared in the domesticated silver fox cultivated by Dmitry Belyayev's breeding experiment. However, in 2015 canine researcher Raymond Coppinger found historical evidence that Belyayev's foxes originated in fox farms on Prince Edward Isla... | Wikipedia - Domestication syndrome - In animals > Challenge | 345 | 1,782 | null |
But, the observation of changed neural crest cell genes between wild and domestic populations need only reveal changes to features derived from neural crest, it does not support the claim of a common underlying genetic architecture that causes all of the domestication syndrome traits in all of the different animal spec... | Wikipedia - Domestication syndrome - In animals > Challenge | 307 | 1,748 | null |
Section: In plants > Cereal genes by trait. Control of the syndrome traits in cereals is by: Shattering SH1 in sorghum, rice, and maize/corn sh4 in the rachis of rice qPDH1 in soybean Q in wheat LG1 in rice Plant height Rht-B1/Rht-D1 (two orthologous versions of Rht-1 on different subgenomes, Rht standing for reduced h... | Wikipedia - Domestication syndrome - In plants > Cereal genes by trait | 187 | 592 | null |
pyl1, pyl4, pyl6 in the PYL gene family in rice Threshability Q and Nud An-1 (by reducing or eliminating awns) in rice An-2/LABA1 - small awn reduction/barbless awns - in rice GAD1/RAE2 - awn elimination in rice tga1 - naked kernels in maize Flowering time VRN1 in barley, wheat, ryegrass Grain weight GW2 in rice, wheat... | Wikipedia - Domestication syndrome - In plants > Cereal genes by trait | 350 | 1,151 | null |
Article: Doubled haploidy. A doubled haploid (DH) is a genotype formed when haploid cells undergo chromosome doubling. Artificial production of doubled haploids is important in plant breeding. Haploid cells are produced from pollen or egg cells or from other cells of the gametophyte, then by induced or spontaneous chro... | Wikipedia - Doubled haploidy - Summary | 233 | 1,022 | null |
Section: Production of doubled haploids. Doubled haploids can be produced in vivo or in vitro. Haploid embryos are produced in vivo by parthenogenesis, pseudogamy, or chromosome elimination after wide crossing. The haploid embryo is rescued, cultured, and chromosome-doubling produces doubled haploids. The in vitro meth... | Wikipedia - Doubled haploidy - Production of doubled haploids | 317 | 1,406 | null |
Section: Genetics of DH population. In DH method only two types of genotypes occur for a pair of alleles, A and a, with the frequency of ½ AA and ½ aa, while in diploid method three genotypes occur with the frequency of ¼ AA, ½ Aa, ¼ aa. Thus, if AA is desirable genotype, the probability of obtaining this genotype is h... | Wikipedia - Doubled haploidy - Genetics of DH population | 211 | 906 | null |
Section: Applications of DHs plant breeding > Mapping quantitative trait loci. Most of the economic traits are controlled by genes with small but cumulative effects. Although the potential of DH populations in quantitative genetics has been understood for some time, it was the advent of molecular marker maps that provi... | Wikipedia - Doubled haploidy - Applications of DHs plant breeding > Mapping quantitative trait loci | 157 | 853 | null |
Section: Applications of DHs plant breeding > Backcross breeding. In backcross conversion, genes are introgressed from a donor cultivar or related species into a recipient elite line through repeated backcrossing. A problem in this procedure is being able to identify the lines carrying the trait of interest at each gen... | Wikipedia - Doubled haploidy - Applications of DHs plant breeding > Backcross breeding | 269 | 1,308 | null |
Section: Applications of DHs plant breeding > Bulked segregant analysis (BSA). In bulked segregant analysis, a population is screened for a trait of interest and the genotypes at the two extreme ends form two bulks. Then the two bulks are tested for the presence or absence of molecular markers. Since the bulks are supp... | Wikipedia - Doubled haploidy - Applications of DHs plant breeding > Bulked segregant analysis (BSA) | 176 | 835 | null |
Section: Applications of DHs plant breeding > Genetic maps. Genetic maps are very important to understand the structure and organization of genomes from which evolution patterns and syntenic relationships between species can be deduced. Genetic maps also provide a framework for the mapping of genes of interest and esti... | Wikipedia - Doubled haploidy - Applications of DHs plant breeding > Genetic maps | 206 | 1,079 | null |
Section: Applications of DHs plant breeding > Genomics. Although QTL analysis has generated a vast amount of information on gene locations and the magnitude of effects on many traits, the identification of the genes involved has remained elusive. This is due to poor resolution of QTL analysis. The solution for this pro... | Wikipedia - Doubled haploidy - Applications of DHs plant breeding > Genomics | 175 | 857 | null |
Section: Applications of DHs plant breeding > Cultivar development. Uniformity is a general requirement of cultivated line in most species, which can be easily obtained through DH production. There are various ways in which DHs can be used in cultivar production. The DH lines themselves can be released as cultivars, th... | Wikipedia - Doubled haploidy - Applications of DHs plant breeding > Cultivar development | 229 | 1,172 | null |
Article: Downregulation and upregulation. In biochemistry, in the biological context of organisms' regulation of gene expression and production of gene products, downregulation is the process by which a cell decreases the production and quantities of its cellular components, such as RNA and proteins, in response to an ... | Wikipedia - Downregulation and upregulation - Summary | 265 | 1,303 | null |
Section: Downregulation and upregulation of receptors. All living cells have the ability to receive and process signals that originate outside their membranes, which they do by means of proteins called receptors, often located at the cell's surface imbedded in the plasma membrane. When such signals interact with a rece... | Wikipedia - Downregulation and upregulation - Downregulation and upregulation of receptors | 346 | 1,673 | null |
Section: Example: Insulin receptor downregulation. Elevated levels of the hormone insulin in the blood trigger downregulation of the associated receptors. When insulin binds to its receptors on the surface of a cell, the hormone receptor complex undergoes endocytosis and is subsequently attacked by intracellular lysoso... | Wikipedia - Downregulation and upregulation - Example: Insulin receptor downregulation | 341 | 1,761 | null |
Section: Cancer. DNA damage appears to be the primary underlying cause of cancer. DNA damage can also increase epigenetic alterations due to errors during DNA repair. Such mutations and epigenetic alterations can give rise to cancer (see malignant neoplasms). Investigation of epigenetic down- or upregulation of repaire... | Wikipedia - Downregulation and upregulation - Cancer | 345 | 1,418 | null |
Article: Drifty gene hypothesis. The "drifty gene hypothesis" was proposed by the British biologist John Speakman as an alternative to the thrifty gene hypothesis originally proposed by James V Neel in 1962. Speakman's critique of the thrifty gene hypothesis is based on an analysis of the pattern and level of mortality... | Wikipedia - Drifty gene hypothesis - Summary | 336 | 1,717 | null |
However, if selection has only been acting for the past 15,000 years then there has been insufficient time for thrifty genes to spread at all. It is argued instead that the modern distribution of the obese phenotype likely comes about because of genetic drift in the genes encoding the regulation system controlling an u... | Wikipedia - Drifty gene hypothesis - Summary | 309 | 1,557 | null |
This critique was published back-to-back with the original 'drifty gene' paper in the International Journal of Obesity in November 2008. Prentice et al predicted that the emerging molecular genetics field would ultimately provide a way to test between the adaptive 'thrifty gene' idea and the non-adaptive 'drifty gene' ... | Wikipedia - Drifty gene hypothesis - Summary | 237 | 1,218 | null |
Section: Historical background. Working in the early 20th century T.H. Morgan, was the first to use Drosophila to explore heredity. Primarily on the basis of work with D. melanogaster, Morgan and his colleagues C.B. Bridges, A.H. Sturtevant, and H.J. Mueller developed a chromosome theory of heredity, for which Morgan w... | Wikipedia - Drosophila hybrid sterility - Historical background | 164 | 721 | null |
Section: Experimentation. In the off-spring of crosses between Drosophila simulans and its island derivative Drosophila mauritiana, female hybrids are fertile but male hybrids are sterile. Recent studies have shown that a critical gene for gender determination in Drosophila known as the sex-lethal gene is highly misreg... | Wikipedia - Drosophila hybrid sterility - Experimentation | 327 | 1,400 | null |
Therefore, Y-autosome interactions are ruled out in this type of hybrid sterility. Since cytoplasmic factors can be compatible between these species, such factors are also dismissed as the cause of sterility. However, in Drosophila paulistorum there is information suggesting that if Y chromosome and cytoplasm are from ... | Wikipedia - Drosophila hybrid sterility - Experimentation | 308 | 1,507 | null |
Article: Dynamical genetics. Dynamical genetics is a subfield of molecular biology and genetics that studies phenomena in which physiological protein complexes alter DNA. The study of such mechanisms is important because they promote useful functions, for example the immune system recombination (on the individual scale... | Wikipedia - Dynamical genetics - Summary | 332 | 1,634 | null |
Article: Ectoderm specification. In Xenopus laevis, the specification of the three germ layers (endoderm, mesoderm and ectoderm) occurs at the blastula stage. Great efforts have been made to determine the factors that specify the endoderm and mesoderm. On the other hand, only a few examples of genes that are required f... | Wikipedia - Ectoderm specification - Summary | 261 | 965 | null |
Section: Ectodermin and FAM > Biological role of Ectodermin and FAM. The protein Ectodermin, firstly identified in Xenopus embryos, promotes ectodermal fate and suppresses the mesoderm formation mediated by the signaling of Transforming Growth Factor β (TGFβ) and Bone Morphogenic Proteins (BMP), members of the TGFβ-sup... | Wikipedia - Ectoderm specification - Ectodermin and FAM > Biological role of Ectodermin and FAM | 337 | 1,281 | null |
Section: Ectodermin and FAM > Identification of Ectodermin and FAM. A cDNA library from the blastula stage of a frog embryo was cloned into RNA expression plasmids to generate synthetic mRNA. The mRNA was then injected into several Xenopus embryos at a four-cell stage and looked in early blastula embryos for an expansi... | Wikipedia - Ectoderm specification - Ectodermin and FAM > Identification of Ectodermin and FAM | 157 | 638 | null |
Section: Ectodermin and FAM > Ectodermin and FAM localization. Ectodermin mRNA is maternally deposited in the animal pole of the egg. In the early blastula stage of the embryo, Ectodermin mRNA and protein forms a gradient that goes from the animal pole (highest concentration) down to the marginal zone (lowest concentra... | Wikipedia - Ectoderm specification - Ectodermin and FAM > Ectodermin and FAM localization | 231 | 966 | null |
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