scholarly journals Reconstruction of female heterogamety from admixture of XX-XY and ZZ-ZW sex-chromosome systems within a frog species

2018 ◽  
Vol 27 (20) ◽  
pp. 4078-4089 ◽  
Author(s):  
Mitsuaki Ogata ◽  
Max Lambert ◽  
Tariq Ezaz ◽  
Ikuo Miura
Keyword(s):  
Sex Chromosome ◽  
Female Heterogamety ◽  
Frog Species

Weak male-determining genes and female heterogamety in Chironomus tentans

1984 ◽  
Vol 26 (6) ◽  
pp. 748-751
Author(s):  
Ray Feraday
Keyword(s):  
Sex Determination ◽  
Sex Chromosome ◽  
Chironomus Tentans ◽  
Female Development ◽  
Female Heterogamety ◽  
Dominant Female

Female heterogamety in the midge Chironomus tentans has been previously reported and attributed to a dominant female determiner. Published results are not consistent with the interpretation, and the female heterogamety, if any, can be better explained by a model involving a weakened male determiner. Suggestions are made for crosses between populations with different sex-determining mechanisms that would discriminate between models for the evolution of female heterogamety, and serve to determine whether indeed female development is the norm in the absence of any parental sex chromosomes.Key words: Chironomus, heterogamety, sex determination, sex chromosome.

scholarly journals Using conventionalF-statistics to study unconventional sex-chromosome differentiation

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3207 ◽  
Author(s):  
Nicolas Rodrigues ◽  
Christophe Dufresnes
Keyword(s):  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Rana Temporaria ◽  
Microsatellite Data ◽  
Homologous Chromosomes ◽  
Chromosome Differentiation ◽  
Population Analyses ◽  
Hyla Arborea ◽  
Frog Species ◽  
Heterogametic Sex

Species with undifferentiated sex chromosomes emerge as key organisms to understand the astonishing diversity of sex-determination systems. Whereas new genomic methods are widening opportunities to study these systems, the difficulty to separately characterize their X and Y homologous chromosomes poses limitations. Here we demonstrate that two simpleF-statistics calculated from sex-linked genotypes, namely the genetic distance (Fst) between sexes and the inbreeding coefficient (Fis) in the heterogametic sex, can be used as reliable proxies to compare sex-chromosome differentiation between populations. We correlated these metrics using published microsatellite data from two frog species (Hyla arboreaandRana temporaria), and show that they intimately relate to the overall amount of X–Y differentiation in populations. However, the fits for individual loci appear highly variable, suggesting that a dense genetic coverage will be needed for inferring fine-scale patterns of differentiation along sex-chromosomes. The applications of theseF-statistics, which implies little sampling requirement, significantly facilitate population analyses of sex-chromosomes.

Evidences for a Multiple Sex Chromosome System with Female Heterogamety inApareiodon Affinis(Pisces, Parodontidae)

Caryologia ◽  
1980 ◽  
Vol 33 (1) ◽  
pp. 83-91 ◽  
Author(s):  
Orlando Moreira Filho ◽  
Luiz Antonio Carlos Bertollo ◽  
Pedro Manoel Galetti Junior
Keyword(s):  
Sex Chromosome ◽  
Female Heterogamety ◽  
Sex Chromosome System

scholarly journals Drift-induced selection between male and female heterogamety

2017 ◽  
Author(s):  
Carl Veller ◽  
Pavitra Muralidhar ◽  
George W. A. Constable ◽  
Martin A. Nowak
Keyword(s):  
Sex Chromosomes ◽  
Evolutionary Dynamics ◽  
Sex Chromosome ◽  
Neutral Evolution ◽  
Theoretical Studies ◽  
Diffusion Approximations ◽  
Evolutionary Transitions ◽  
Directional Bias ◽  
Male And Female ◽  
Female Heterogamety

AbstractEvolutionary transitions between male and female heterogamety are common in both vertebrates and invertebrates. Theoretical studies of these transitions have found that, when all genotypes are equally fit, continuous paths of intermediate equilibria link the two sex chromosome systems. This observation has led to a belief that neutral evolution along these paths can drive transitions, and that arbitrarily small fitness differences among sex chromosome genotypes can determine the system to which evolution leads. Here, we study stochastic evolutionary dynamics along these equilibrium paths. We find non-neutrality, both in transitions retaining the ancestral pair of sex chromosomes and in those creating a new pair. In fact, substitution rates are strongly biased in favor of dominant sex determining chromosomes, which fix with higher probabilities than mutations of no effect. Using diffusion approximations, we show that this non-neutrality is a result of ‘drift-induced selection’ operating at every point along the equilibrium paths: stochastic jumps off the paths return, on average, with a directional bias in favor of the dominant segregating sex chromosome. Our results offer novel explanations for the ubiquity of transitions between male and female heterogamety and the preponderance of dominant major sex determining genes.

scholarly journals Evolution of sex determination and heterogamety changes in section Otites of the genus Silene

2018 ◽  
Author(s):  
Veronika Balounova, ◽  
Roman Gogela ◽  
Radim Cegan ◽  
Patrik Cangren ◽  
Jitka Zluvova ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Sex Determination ◽  
Sex Chromosome ◽  
The Other ◽  
Close Relative ◽  
Sequence Analyses ◽  
Female Heterogamety ◽  
Genus Silene ◽  
Plant Sex ◽  
Male Heterogamety

AbstractSwitches in heterogamety occasionally occur both in animals and plants, although plant sex determination systems are mostly more recently evolved than those of animals, and have had less time for switches to occur. However, our previous research revealed a switch in heterogamety in section Otites of the plant genus Silene.Here we analyse in detail the evolution of genetic sex determination in section Otites, which is estimated to have evolved about 0.55 MYA. Our study confirms female heterogamety in S. otites and newly reveals female heterogamety in S. borysthenica. Sequence analyses and genetic mapping show that the sex-linked regions of these two species are the same, but the region in S. colpophylla, a close relative with male heterogamety, is different. The sex chromosome pairs of S. colpophylla and S. otites each correspond to an autosome of the other species, and both differ from the XY pair in S. latifolia, in a different section of the genus. Our phylogenetic analysis suggests a possible change from female to male heterogamety within Silene section Otites, making these species suitable for detailed studies of the events involved.

scholarly journals Preface

2021 ◽  
Vol 376 (1832) ◽  
pp. 20200088
Author(s):  
Lukáš Kratochvíl ◽  
Matthias Stöck
Keyword(s):  
Sex Determination ◽  
Sex Chromosomes ◽  
Chromosome Evolution ◽  
Sex Chromosome ◽  
Sex Chromosome Evolution ◽  
Evolution Of Sex ◽  
Linkage Groups ◽  
Theme Issue ◽  
Female Heterogamety

This preface introduces the two parts of a theme issue on vertebrate sex chromosome evolution (title below). We invited and edited 22 articles concerning the following main topics (Part 1): sex determination without sex chromosomes and/or governed by epigenetics; origin of sex-determining genes; reasons for differentiation of sex chromosomes and differences in their rates of differentiation as well as (Part 2): co-option of the same linkage groups into sex chromosomes; is differentiation of sex chromosomes a unidirectional pathway?; consequences of differentiated sex chromosomes; differences in differentiation of sex chromosomes under male versus female heterogamety; evolution of sex chromosomes under hybridization and polyploidy. This article is part of the theme issue ‘Challenging the paradigm in sex chromosome evolution: empirical and theoretical insights with a focus on vertebrates (Part I)’.

scholarly journals Genomic Data Reveal Conserved Female Heterogamety in Giant Salamanders with Gigantic Nuclear Genomes

2019 ◽  
Vol 9 (10) ◽  
pp. 3467-3476 ◽  
Author(s):  
Paul M. Hime ◽  
Jeffrey T. Briggler ◽  
Joshua S. Reece ◽  
David W. Weisrock
Keyword(s):  
Sex Determination ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Model Organisms ◽  
Reduced Representation ◽  
Non Invasive ◽  
Female Heterogamety ◽  
Genome Wide ◽  
Great Utility ◽  
Genomic Regions

Systems of genetic sex determination and the homology of sex chromosomes in different taxa vary greatly across vertebrates. Much progress remains to be made in understanding systems of genetic sex determination in non-model organisms, especially those with homomorphic sex chromosomes and/or large genomes. We used reduced representation genome sequencing to investigate genetic sex determination systems in the salamander family Cryptobranchidae (genera Cryptobranchus and Andrias), which typifies both of these inherent difficulties. We tested hypotheses of male- or female-heterogamety by sequencing hundreds of thousands of anonymous genomic regions in a panel of known-sex cryptobranchids and characterized patterns of presence/absence, inferred zygosity, and depth of coverage to identify sex-linked regions of these 56 gigabase genomes. Our results strongly support the hypothesis that all cryptobranchid species possess homologous systems of female heterogamety, despite maintenance of homomorphic sex chromosomes over nearly 60 million years. Additionally, we report a robust, non-invasive genetic assay for sex diagnosis in Cryptobranchus and Andrias which may have great utility for conservation efforts with these endangered salamanders. Co-amplification of these W-linked markers in both cryptobranchid genera provides evidence for long-term sex chromosome stasis in one of the most divergent salamander lineages. These findings inform hypotheses about the ancestral mode of sex determination in salamanders, but suggest that comparative data from other salamander families are needed. Our results further demonstrate that massive genomes are not necessarily a barrier to effective genome-wide sequencing and that the resulting data can be highly informative about sex determination systems in taxa with homomorphic sex chromosomes.

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