DOCSLIB.ORG

Popgen4: Assortative Mating

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Popgen4: Assortative Mating PopGen4: Assortative mating Introduction Although random mating is the most important system of mating in many natural populations, non-random mating can also be an important mating system in some populations. Non-random mating results in changes in the genotype frequencies in the population, i.e., how the alleles are put together into genotypes, but it does NOT change the allele frequencies themselves. Since genotype frequencies will be affected, non-random mating results in a deviation from Hardy-Weinberg equilibrium. For the purpose of this course we will divide mating systems into four broad categories. Mating system Random Mate choice is independent of both phenotype and genotype Positive assortment Mate choice is based on similarity of phenotype Negative assortment Mate choice is based on dissimilarity of phenotype Inbreeding Mating with relatives at a rate greater than expected by chance The topic of these notes is ASSORTATIVE MATING, the non-random mating system where mates are chosen by their phenotypes. Positive assortative mating Under a system of POSITIVE ASSORTATIVE MATING individuals choose mates that are phenotypically like themselves. Note that under random mating there will always be some fraction of the population that mate with phenotypically similar individuals. So when we say positive assortment, we mean that the mating of phenotypically similar individuals is occurring at a frequency that is greater than expected by chance. We can look to ourselves, humans, for an example of positive assortative mating. It has been shown that there is significant assortment according to phenotypes such as height, IQ score and race. There is assortment for certain socioeconomic traits. Interestingly, in the US, one of the highest correlations is found between the numbers of rooms in the homes of the parents of married couples. To consider the effect of positive assortment on genotype frequencies, let: Genotype AA Aa aa Frequency P1 P2 P3 Note: We are NOT assuming HW frequencies here Even though we do not assume HW equilibrium, we still compute p and q as before: p = P1 + (1/2)P2 q = P3 + (1/2)P2 Now consider that the frequency of positive assortment in a population is equal to α: α = the frequency of AA x AA, Aa x Aa and aa x aa in addition to random mating and (1 - α) is the random mating fraction Remember that the three types of mating under positive assortment yield the following: AA x AA = 100% AA Aa x Aa = (1/4)AA + (1/2)Aa + (1/4)aa aa x aa = 100% aa ’ ’ 1 The frequencies of AA, Aa, and aa in the next generation (P1 P2 and P3 ) are as follows: P ' = (1−α )p 2 + α(P + (1/ 4)P ) 1 142 43 14214 4342 Freq of AA under Freq of AA under positive random mating assortment has two sources: 100% from AAxAA, and 1/4 from AaxAa P' = (1−α )2 pq + α((1/ 2)P ) 2 142 43 142 432 Freq of Aa under Freq of Aa under positive random mating assortment has one source: 1/2 from AaxAa matings P ' = (1−α )q 2 + α(P + (1/ 4)P ) 3 142 43 14234 4342 random mating positive assortment component component Note that when α > 1, the frequencies will no longer sum to 1. To get the population frequencies you need to ’ ’ 1 standardize by the sum P1 + P2 + P3 . We can look at the effect on heterozygosity under this system of mating (plot A below). Remember that we have assumed a very simplistic scenario as heterozygotes can be distinguished from homozygotes, so no AA × Aa mating will occur for this locus. The second plot below (B) shows the effect of dominance [formula not shown]. A. Effect of complete (α = 1) and partial B. Effect of positive assortative mating (α = 0.75) positive assortative mating on (α = 1) on heterozygosity under complete heterozygosity dominance [Formula not shown] 0.6 0.6 p = q = 0.5 otes otes p = q = 0.5 otes otes 0.5 yg 0.5 yg 0.4 0.4 0.3 0.3 of heteroz α = 0.75 of heteroz y y 0.2 0.2 α = 1.0 + dominance uenc uenc q q 0.1 0.1 α = 1.0 Fre Fre 0 0 1 3 5 7 9 1113151719 1 3 5 7 9 111315171921 generation generation When there is no dominance effect the frequency of heterozygote genotypes in the population declines very rapidly. The frequency will rapidly go to zero when the effectiveness of positive assortment is 100% (α = 1). When positive assortment is not complete (e.g., α = 0.75) The population heterozygosity declines quickly until is reaches an equilibrium value (in the case above equilibrium is about 0.21). Dominance slows the rate to equilibrium considerably by the effect of dominance. In the example above the ’ frequency of heterozygotes will eventually, for all practical purposes, go to zero; P 2 = 0.005 after 198 generations. In example A above p = q = 0.5. Genotype frequencies at generation zero and after 20 generations are as follows. Genotype frequencies Generation AA Aa aa 0 0.250 0.5 0.250 20 (α = 0.75) 0.396 0.208 0.396 Check for yourself; before and after 20 generations p = q = 0.5 Positive assortative mating and the process of speciation We do not cover the topic of speciation in this course. However, it is worth noting the potentially important role that positive assortative mating could have in the process of speciation. There are many hypotheses about the causes of speciation. One hypothesized mechanism is called REINFORCEMENT. Under reinforcement, natural selection acts to favour the process of positive assortative mating. The idea is based on the premise that mating between individuals from populations that have diverged will result in offspring with reduced fitness; hence, selection will favour positive assortment because reproductive effort will not be wasted on producing less-fit “hybrid” offspring. Under these circumstances assortative mating could lead to increased reproductive isolation and eventually the final stages of the speciation process. The type of selection that would lead to reinforcement is called DISRUPTIVE SELECTION; a selective pressure for divergence into two populations into ecologically distinct types. Until now I have relied on your intuitive sense of what a species is. A discussion of species concepts is well beyond the scope of this course, so for the purpose of our discussion we will assume a species is an independent evolutionary lineage, and we are interested in what role positive assortative mating might play in the process of splitting one interbreeding population into two independent evolutionary lineages. The consensus opinion is that the process of reinforcement is probably rare. However, recent examples, many coming from Pied flycatcher colour polymorphism lakes filled with closely related fish species, is leading many biologists to think that reinforcement is worth a closer look. A good example of positive assortative mating and reinforcement of a species barrier was presented by Sætre et al. (1998) for species of flycatcher. The power of this example comes from studying mate choice in two populations (or close species) where the two ranges overlap (SYMPATRY), and comparing the patterns with those occurring in regions where the two populations occur singly (ALLOPATRY). The pied flycatcher (Ficedula hypoleuca) is typically black and white over much of its distribution. However, in parts of Central Allopatric type Sympatric type and Eastern Europe the pied flycatcher is sympatric with another species, the collared flycatcher (F. albicollis), and in the areas of Adapted from Butlin and Tregenza 1998 sympatry, the males are a dull brown rather than black and whites. In Central and Eastern Europe, where the Pied flycatcher is sympatric with the collared flycatcher, the two species exhibit distinct colour differences Pied Flycatcher Collared Flycatcher (F. hypoleuca) (F. albicollis) Sympatry Allopatry Allopatry Sætre et al. (1998) Four points: 1. Between species matings are more rare than expected, and hybrids have reduced fitness 2. Phylogenetics indicated that plumage polymorphism is derived. 3. Females of sympatric populations/species prefer males that have the sympatric colouring rather than the allopatric colouring (positive assortment). 4. Pied females exhibit the opposite preference (for dull brown males) than is exhibited in most other populations; in most populations the preference is for striking black and white males. Mate preferences of female flycatchers Adapted from Sætre et al. (1998) It is likely that the genetic basis of colour polymorphism in Pied flycatchers is more complicated than our single locus model above. Moreover the flycatcher case involves interbreeding between two populations and our model is based on a single random mating population. Nevertheless our model does provide some sense of positive assortative mating for change in genotype frequencies in a population, and the Pied flycatcher provides an example of the relevance of such non-random mating systems to evolution. Positive assortment keynotes: • Increases homozygosity, thereby preventing HW equilibrium • Does not affect allele frequencies • Affects only those genes related to the phenotype by which mates are chosen. The other loci can be in HW equilibrium • Results in gametic phase disequilibrium because it prevents equilibrium of allele frequencies between the locus subject to assortment and other loci in the genome • Dominance dilutes the effect of positive assortment Negative assortative mating NEGATIVE ASSORTATIVE MATING is the avoidance of mating with phenotypically similar individuals. This is also called DISASSORTATIVE MATING. Of course there will be a certain frequency of mating among dissimilar individuals in a random mating population; so we are interested in the cases where the frequency of disassortment is greater than expectations under random mating. Negative assortative mating is an important breeding pattern in plants.
Load more

Recommended publications
  • A Robust Test for Assortative Mating
    European Journal of Human Genetics (2000) 8, 119–124 © 2000 Macmillan Publishers Ltd All rights reserved 1018–4813/00 $15.00 y www.nature.com/ejhg ARTICLE A robust test for assortative mating Emmanuelle G´enin1, Carole Ober2, Lowell Weitkamp3 and Glenys Thomson1 1Department of Integrative Biology, University of California, Berkeley, CA, USA; 2Department of Human Genetics, University of Chicago, Chicago, IL, USA; 3Department of Psychiatry and Division of Genetics, University of Rochester Medical Center, Rochester, NY, USA Testing for random mating in human populations is difficult due to confounding factors such as ethnic preference and population stratification. With HLA, the high level of polymorphism is an additional problem since it is rare for couples to share the same haplotype. Focus on an ethnically homogeneous population, where levels of polymorphism at HLA loci are more limited, may provide the best situation in which to detect non-random mating. However, such populations are often genetic isolates where there may be inbreeding to an extent that is difficult to quantify and account for. We have developed a test for random mating at a multiallelic locus that is robust to stratification and inbreeding. This test relies on the availability of genotypic information from the parents of both spouses. The focus of the test is on families where there is allele sharing between the parents of both spouses, so that potential spouses could share an allele. Denoting the shared allele at the locus of interest by A, then under the assumption of random mating, heterozygous parents AX should transmit allele A equally as frequently as allele X to their offspring.
    [Show full text]
  • Assortative Mating and Sexual Dimorphism in the Common Tern
    Wilson Bull., 98(l), 1986, pp. 93-100 ASSORTATIVE MATING AND SEXUAL DIMORPHISM IN THE COMMON TERN MALCOLM C. COULTER ’ ABSTRACT.-Although male and female Common Terns (Sterna hirundo)are almost iden- tical in plumage and in most external body measurements, males have longer, deeper, and wider bills than do females. Two patterns in the size relationships between mates are dem- onstrated. First, males tend to have larger bills than their mates. This may be explained by random mating, given the sexual dimorphism observed. Second, Common Terns mate assortatively according to bill size. This pattern may result if there is either a year-to-year component or an age component of bill size variation and if first-breeding birds return to the colony after experienced breeders have already established pairbonds and most birds retain their mates from year to year. ReceivedI I Jan. 1985, accepted30 Aug. 1985. Mating patterns may contribute significantly to the genetic structure of bird populations. When similar individuals tend to mate with each other (i.e., mating is positively assortative), progeny are more homozygous, and phenotypic variability in the population may be greater than when mating is either random or disassortative (Falconer 198 1, Halliday 1978, Par- tridge 1983; but see Lande 1977). Positive assortative mating based on the color morphs has been demonstrated for white and blue morphs of the Snow Goose (Chen cuerulescens) (Cooke et al. 1976). This involved discrimination according to a discrete variable (i.e., distinct blue and white morphs). It is more difficult to demonstrate mating patterns according to continuous variables, particularly in wild populations.
    [Show full text]
  • Natural Selection in Action During Speciation
    Natural selection in action during speciation Sara Via1 Departments of Biology and Entomology, University of Maryland, College Park, MD 20742 The role of natural selection in speciation, first described by The Spyglass Darwin, has finally been widely accepted. Yet, the nature and time A course of the genetic changes that result in speciation remain mysterious. To date, genetic analyses of speciation have focused almost exclusively on retrospective analyses of reproductive iso- lation between species or subspecies and on hybrid sterility or Intrinsic barriers to Ancestral inviability rather than on ecologically based barriers to gene flow. gene flow evolve… Population Diverged “Good Species” However, if we are to fully understand the origin of species, we Populations must analyze the process from additional vantage points. By studying the genetic causes of partial reproductive isolation be- The Magnifying Glass tween specialized ecological races, early barriers to gene flow can B be identified before they become confounded with other species differences. This population-level approach can reveal patterns that become invisible over time, such as the mosaic nature of the genome early in speciation. Under divergent selection in sympatry, Ancestral Intrinsic barriers to the genomes of incipient species become temporary genetic mo- Population gene flow evolve… Diverged “Good Species” saics in which ecologically important genomic regions resist gene Populations exchange, even as gene flow continues over most of the genome. Analysis of such mosaic genomes suggests that surprisingly large Fig. 1. Two ways to study the process of speciation, which is visualized here genomic regions around divergently selected quantitative trait loci as a continuum of divergence from a variable population to a divergent pair of populations, and on through the evolution of intrinsic barriers to gene flow can be protected from interrace recombination by ‘‘divergence to the recognition of good species.
    [Show full text]
  • Sympatric Speciation As a Consequence of Male Pregnancy in Seahorses
    Sympatric speciation as a consequence of male pregnancy in seahorses Adam G. Jones†‡, Glenn I. Moore§, Charlotta Kvarnemo¶, DeEtte Walkerʈ, and John C. Aviseʈ †School of Biology, 310 Ferst Drive, Georgia Institute of Technology, Atlanta, GA 30332; §Department of Zoology, University of Western Australia, Nedlands, Western Australia 6009, Australia; ¶Department of Zoology, Stockholm University, S-106 91 Stockholm, Sweden; and ʈDepartment of Genetics, University of Georgia, Athens, GA 30602 Contributed by John C. Avise, April 4, 2003 The phenomenon of male pregnancy in the family Syngnathidae where he fertilizes them and enjoys complete confidence of pater- (seahorses, pipefishes, and sea dragons) undeniably has sculpted nity (21, 22). Because seahorses are monogamous (20, 22–25), the course of behavioral evolution in these fishes. Here we explore individuals of both sexes must place a high premium on finding a another potentially important but previously unrecognized conse- partner with a similar reproductive capacity. Otherwise, eggs or quence of male pregnancy: a predisposition for sympatric specia- brood pouch space will be wasted. Reproductive output is positively tion. We present microsatellite data on genetic parentage that correlated with size for both sexes (20), and selection therefore show that seahorses mate size-assortatively in nature. We then favors size-assortative mating. Our goal was to evaluate the poten- develop a quantitative genetic model based on these empirical tial importance of assortative mating to the evolutionary legacy of findings to demonstrate that sympatric speciation indeed can occur this group. Specifically, our approaches were to (i) document under this mating regime in response to weak disruptive selection genetically that assortative pairing by similarly sized adults underlies on body size.
    [Show full text]
  • Assortative Mating and Income Inequality
    NBER WORKING PAPER SERIES MARRY YOUR LIKE: ASSORTATIVE MATING AND INCOME INEQUALITY Jeremy Greenwood Nezih Guner Georgi Kocharkov Cezar Santos Working Paper 19829 http://www.nber.org/papers/w19829 NATIONAL BUREAU OF ECONOMIC RESEARCH 1050 Massachusetts Avenue Cambridge, MA 02138 January 2014 This paper is prepared for the 2014 American Economic Review Papers and Proceedings. The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research. Nezih Guner thanks the European Research Council (ERC Grant 263600) for financial support. NBER working papers are circulated for discussion and comment purposes. They have not been peer- reviewed or been subject to the review by the NBER Board of Directors that accompanies official NBER publications. © 2014 by Jeremy Greenwood, Nezih Guner, Georgi Kocharkov, and Cezar Santos. All rights reserved. Short sections of text, not to exceed two paragraphs, may be quoted without explicit permission provided that full credit, including © notice, is given to the source. Marry Your Like: Assortative Mating and Income Inequality Jeremy Greenwood, Nezih Guner, Georgi Kocharkov, and Cezar Santos NBER Working Paper No. 19829 January 2014 JEL No. D31,J11,J12,J22 ABSTRACT Has there been an increase in positive assortative mating? Does assortative mating contribute to household income inequality? Data from the United States Census Bureau suggests there has been a rise in assortative mating. Additionally, assortative mating affects household income inequality. In particular, if matching in 2005 between husbands and wives had been random, instead of the pattern observed in the data, then the Gini coefficient would have fallen from the observed 0.43 to 0.34, so that income inequality would be smaller.
    [Show full text]
  • Assortative Mating at Loci Under Recent Natural Selection in Humans T Akihiro Nishia,*, Marcus Alexanderb, James H
    BioSystems 187 (2020) 104040 Contents lists available at ScienceDirect BioSystems journal homepage: www.elsevier.com/locate/biosystems Assortative mating at loci under recent natural selection in humans T Akihiro Nishia,*, Marcus Alexanderb, James H. Fowlerc, Nicholas A. Christakisb,d a Department of Epidemiology, UCLA Fielding School of Public Health, Los Angeles, CA 90095, USA b Yale Institute for Network Science, Yale University, CT 06520, USA c Division of Medical Genetics and Department of Political Science, University of California, San Diego, La Jolla, CA, 92103, USA d Department of Sociology, Ecology and Evolutionary Biology, Medicine, Biomedical Engineering, and Statistics & Data Science, Yale University, New Haven, CT, USA ARTICLE INFO ABSTRACT Keywords: Genetic correlation between mates at specific loci can greatly alter the evolutionary trajectory of a species. Mate choice Genetic assortative mating has been documented in humans, but its existence beyond population stratification Assortative mating (shared ancestry) has been a matter of controversy. Here, we develop a method to measure assortative mating Positive selection across the genome at 1,044,854 single-nucleotide polymorphisms (SNPs), controlling for population stratifica- Humans tion and cohort-specific cryptic relatedness. Using data on 1683 human couples from two data sources, we find evidence for both assortative and disassortative mating at specific, discernible loci throughout the entire genome. Then, using the composite of multiple signals (CMS) score, we also show that the group of SNPs ex- hibiting the most assortativity has been under stronger recent positive selection. Simulations using realistic inputs confirm that assortative mating might indeed affect changes in allele frequency over time. These results suggest that genetic assortative mating may be speeding up evolution in humans.
    [Show full text]
  • Estimation of Assortative Mating Preferences in the Arctic Skua
    Heredity (1976),36 (2), 235-244 ESTIMATION OF ASSORTATIVE MATING PREFERENCES IN THE ARCTIC SKUA J. W. F. DAVIS and P. O'DONALD Department of Genetics, University of Cambridge, Milton Road, Cambridge CB4 I XH, England Received20.x.75 SUMMARY Methods are described for the maximum likelihood estimation of mating preferences in models of assortative mating for monogamous and polygamous organisms. These methods are applied to data of matings of the three pheno- types, pale, intermediate and dark of the Arctic Skua. The data were obtained by exhaustive surveys of the Arctic Skua populations on the islands of Fair Isle and Foula. The data give evidence of significant assortative mating of pale birds on Foula and intermediate birds on Fair Isle. The combined data show that there is very highly significant assortative mating, but only of intermediates. In previous surveys, data, in which intermediates and darks were not distinguished, were obtained from a number of islands in the Shetlands. These data, combined with the present data, show that the overall assortative mating of pale is very highly significant with no evidence of heterogeneity. The assortative mating of intermediate birds on Fair Isle agrees with other evidence showing that intermediate males have an advantage as a result of sexual selection. 1. INTRODUCTION MODELS of assortative mating (O'Donald, 1960; Karlin, 1969) can be described in terms of preferences among some individuals to mate with others phenotypically similar or dissimilar to themselves. The proportions of individuals who mate preferentially can be estimated from the actual numbers of the different matings. O'Donald, Davis and Broad (1974) obtained such estimates from matings of the phenotypes of the Arctic Skua (Stercorarius parasiticus), a monogamous seabird that lives in loose colonies.
    [Show full text]
  • Genomic Linkage of Male Song and Female Acoustic Preference QTL Underlying a Rapid Species Radiation
    Genomic linkage of male song and female acoustic preference QTL underlying a rapid species radiation Kerry L. Shaw1 and Sky C. Lesnick Department of Biology, University of Maryland, College Park, MD 20742 Edited by May R. Berenbaum, University of Illinois at Urbana-Champaign, Urbana, IL, and approved April 10, 2009 (received for review January 9, 2009) The genetic coupling hypothesis of signal-preference evolution, directional sexual selection when signal and preference distri- whereby the same genes control male signal and female prefer- butions are mismatched within a population (11). Two recent ence for that signal, was first inspired by the evolution of cricket studies, one in the olfactory realm (12) and the other in the visual acoustic communication nearly 50 years ago. To examine this realm (13), have suggested that physical linkage or pleiotropy hypothesis, we compared the genomic location of quantitative might bolster behavioral coupling of sexual signaling in the face trait loci (QTL) underlying male song and female acoustic prefer- of divergent evolution, an idea with a long history (1, 6) but little ence variation in the Hawaiian cricket genus Laupala. We docu- empirical support. Furthermore, recent modeling suggests that ment a QTL underlying female acoustic preference variation be- physical linkage can promote a genetic correlation between tween 2 closely related species (Laupala kohalensis and Laupala signal and preference and thereby enhance coevolution in sexual paranigra). This preference QTL colocalizes with a song QTL iden- signaling systems (14). tified previously, providing compelling evidence for a genomic In crickets (family Gryllidae), males sing with specialized struc- linkage of the genes underlying these traits.
    [Show full text]
  • On the Origin of Species by Sympatric Speciation
    letters to nature population into two. Fortunately, the hypergeometic phenotypic model7–9 is 21. Turner, G. F. & Burrows, M. T. A model of sympatric speciation by sexual selection. Proc. R. Soc. Lond. 10 B 260, 287–292 (1995). applicable under the conditions required for sympatric speciation . For a 22. Galis, F. & Metz, J. A. J. Why are there so many cichlid species? Trends Ecol. Evol. 13, 1–2 (1998). quantitative trait with the possible phenotypes 0, 1, …, n, this model provides, 23. van Doorn, G. S., Noest, A. J. & Hogeweg, P. Sympatric speciation and extinction driven by as a sum of certain hypergeometric functions, the probability Rði; j; kÞ of environment dependent sexual selection. Proc. R. Soc. Lond. B 265, 1915–1919 (1998). 24. Axelrod, H. R. The Most Complete Colored Lexicon of Cichlids (TFH Publications, Neptune City, 1996). two parents with phenotypes i and j producing an offspring with phenotype 25. Seehausen, O., van Alphen, J. J. M. & Witte, F. Cichlid fish diversity threatened by eutrophication that k (refs 8–10). curbs sexual selection. Science 277, 1808–1811 (1997). 26. Seehausen, O. & van Alphen, J. J. M. The effect of male coloration on female mate choice in closely Implementation of the model. We considered haploid individuals with the related Lake Victoria cichlids (Haplochromis nyererei complex). Behav. Ecol. Sociobiol. 42, 1–8 (1998). phenotype in their m-th trait determined by the number of alleles 1 at the nm 27. Lewontin, R. C., Kirk, D. & Crow, J. F. Selective mating, assortative mating and inbreding: definitions and implications. Eugen. Quart. 15, 141–143 (1966).
    [Show full text]
  • Ultraviolet Sexual Dimorphism and Assortative Mating in Blue Tits
    Ultraviolet sexual dimorphism and assortative mating in blue tits Sta¡an Andersson*, Jonas O« rnborg and Malte Andersson Department of Zoology, University of Go« teborg, Medicinaregatan 18, S- 413 90 Go« teborg, Sweden In spite of strong evidence for viability-based sexual selection and sex ratio adjustments, the blue tit, Parus caeruleus, is regarded as nearly sexually monomorphic and no epigamic signals have been found. The plumage coloration has not, however, been studied in relation to bird vision, which extends to the UV-A waveband (320^400 nm). Using molecular sex determination and UV/VIS spectrometry, we report here that blue tits are sexually dichromatic in UV/blue spectral purity (chroma) of the brilliant crown patch. It is displayed in courtship by horizontal posturing and erected nape feathers. A previously undescribed sexual dimorphism in crown size (controlling for body size) further supports its role as an epigamic orna- ment. Against `grey-brown' leaf litter and bark during pair formation in early spring, but also against green vegetation, UV contributes strongly to conspicuousness and sexual dimorphism. This should be further enhanced by the UV/bluish early morning skylight (`woodland shade') in which blue tits display. Among 18 breeding pairs, there was strong assortative mating with respect to UV chroma, but not size, of the crown ornament. We conclude that blue tits are markedly sex dimorphic in their own visual world, and that UV/violet coloration probably plays a role in blue tit mate acquisition. Keywords: UV vision; spectral re£ectance; colour signalling; sexual dichromatism; colour contrast; Parus caeruleus (Chen & Goldsmith 1986; Maier 1994; Bowmaker et al.
    [Show full text]
  • 208 Вивчення Популяційних Систем Зелених Жаб (Rana Esculenta Complex) В Харківській …
    208 Вивчення популяційних систем зелених жаб (Rana esculenta complex) в Харківській … УДК: 597.851(477.54) ИЗУЧЕНИЕ ПОПУЛЯЦИОННЫХ СИСТЕМ ЗЕЛЕНЫХ ЛЯГУШЕК (RANA ESCULENTA COMPLEX) В ХАРЬКОВСКОЙ ОБЛАСТИ: ИСТОРИЯ, СОВРЕМЕННОЕ СОСТОЯНИЕ И ПЕРСПЕКТИВЫ Д.А.Шабанов, А.И.Зиненко, А.В.Коршунов, М.А.Кравченко, Г.А.Мазепа Харьковский национальный университет имени В.Н.Каразина (Харьков, Украина) В статье дан обзор среднеевропейских зеленых лягушек (Rana esculenta complex). Описано характерное для их межвидовых гибридов мероклональное наследование (передача одного из геномов без рекомбинации). Описаны основные методы исследования этого явления, а также история изучения зеленых лягушек на территории Харьковской области. В Харьковской области зарегистрированы разные типы популяционных систем зеленых лягушек, в том числе включающие ди- и полиплоидные гибриды. Высказано предположение, что состав популяционных систем зеленых лягушек отражает результат их локальной эволюции и частотно-зависимого отбора гибридных линий, производящих разные типы гамет. Предложена схема, описывающая возможные преобразования популяционных систем в ходе их эволюции. Сформулированы перспективные направления дальнейших исследований разнообразия зеленых лягушек в Харьковской области. Ключевые слова: Rana esculenta complex, триплоиды, тетраплоиды, гибридогенез, мероклональное наследование, популяционные системы, Харьковская область. Мероклональное наследование у Rana esculenta В состав комплекса среднеевропейских зеленых лягушек (Rana esculenta complex) входят три основные формы.
    [Show full text]
  • The Evolutionary Significance of Polyploidy Yves Van De Peer1,2,3,4, Eshchar Mizrachi4,5, and Kathleen Marchal1,3,5,6
    This is a post-print of an article published in Nature Reviews Genetics. The final authenticated version is available online at: https://doi.org/10.1038/nrg.2017.26 The evolutionary significance of polyploidy Yves Van de Peer1,2,3,4, Eshchar Mizrachi4,5, and Kathleen Marchal1,3,5,6 1 Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 927, B-9052 Ghent, Belgium. 2 VIB-UGent Center for Plant Systems Biology, VIB, Technologiepark 927, B-9052 Ghent, Belgium 3 Bioinformatics Institute Ghent, Ghent University, Technologiepark 927, B-9052 Ghent, Belgium 4 Genomics Research Institute (GRI), University of Pretoria, Private Bag X20, Pretoria, 0028, South Africa 5 Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20, Pretoria, 0028, South Africa 6 Department of Information Technology, IDLab, imec, Ghent University, B-9052 Ghent, Belgium Correspondence to Y. V. d. P. [email protected] Abstract Polyploidy, or the duplication of entire genomes, has been observed in both somatic and germ cells, and in both prokaryotic and eukaryotic organisms. Although the consequences of polyploidization are complex and variable, and seem to differ greatly between systems (clonal and non-clonal) and species, there is growing evidence that polyploidization correlates with environmental change or stress. Consequently, although often considered an evolutionary dead end, the short-term adaptive potential of polyploidization is increasingly being acknowledged. Furthermore, once established, the unique retention profile of duplicated genes following whole-genome duplication might explain important longer-term key evolutionary transitions and a general increase in biological complexity. Introduction Polyploid species (BOX 1) have been known for a long time.
    [Show full text]