Recombination is suppressed and variability reduced in a nascent Y chromosome

Berset-Brändli, Laura; Jaquiéry, Julie; Perrin, Nicolas

doi:10.1111/j.1420-9101.2006.01278.x

Cited by 16 publications

(19 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Berset‐Brandli et al . () found that molecular diversities on Y, X and autosomes in H. arborea fall roughly in the ratio 1:3:4. Such ratios are expected for neutrally evolving sex chromosomes that do not recombine.…”

Section: Discussionmentioning

confidence: 98%

Cryptic recombination in the ever‐young sex chromosomes of Hylid frogs

Guerrero

Kirkpatrick

Perrin

2012

J of Evolutionary Biology

Self Cite

View full text Add to dashboard Cite

Sex chromosomes are expected to evolve suppressed recombination, which leads to degeneration of the Y and heteromorphism between the X and Y. Some sex chromosomes remain homomorphic, however, and the factors that prevent degeneration of the Y in these cases are not well understood. The homomorphic sex chromosomes of the European tree frogs (Hyla spp.) present an interesting paradox. Recombination in males has never been observed in crossing experiments, but molecular data are suggestive of occasional recombination between the X and Y. The hypothesis that these sex chromosomes recombine has not been tested statistically, however, nor has the X-Y recombination rate been estimated. Here, we use approximate Bayesian computation coupled with coalescent simulations of sex chromosomes to quantify X-Y recombination rate from existent data. We find that microsatellite data from H. arborea, H. intermedia and H. molleri support a recombination rate between X and Y that is significantly different from zero. We estimate that rate to be approximately 10 5 times smaller than that between X chromosomes. Our findings support the notion that very low recombination rate may be sufficient to maintain homomorphism in sex chromosomes.

show abstract

Section: Discussionmentioning

confidence: 98%

Cryptic recombination in the ever‐young sex chromosomes of Hylid frogs

Guerrero

Kirkpatrick

Perrin

2012

J of Evolutionary Biology

Self Cite

View full text Add to dashboard Cite

show abstract

“…Recombination in H. arborea males is suppressed on all sex-linked markers and drastically repressed on autosomes [29], arguing against local mechanisms such as inversions [37]. Genome-wide effects with phenotypic-sex dependence are likely to stem from meiotic or epigenetic processes [38].…”

Section: Discussionmentioning

confidence: 99%

“…All Eurasian tree frogs have homomorphic sex chromosomes [27]. Male heterogamety was first evidenced in Hyla arborea by sex differences in the allelic distribution of microsatellite markers [28]–[29]. Mapping linkage groups through sibship analyses identified nine sex-linked markers, which all revealed complete absence of male recombination, despite overlapping X-Y allelic distributions [30].…”

Section: Introductionmentioning

confidence: 99%

Ever-Young Sex Chromosomes in European Tree Frogs

et al. 2011

View full text Add to dashboard Cite

Non-recombining sex chromosomes are expected to undergo evolutionary decay, ending up genetically degenerated, as has happened in birds and mammals. Why are then sex chromosomes so often homomorphic in cold-blooded vertebrates? One possible explanation is a high rate of turnover events, replacing master sex-determining genes by new ones on other chromosomes. An alternative is that X-Y similarity is maintained by occasional recombination events, occurring in sex-reversed XY females. Based on mitochondrial and nuclear gene sequences, we estimated the divergence times between European tree frogs (Hyla arborea, H. intermedia, and H. molleri) to the upper Miocene, about 5.4–7.1 million years ago. Sibship analyses of microsatellite polymorphisms revealed that all three species have the same pair of sex chromosomes, with complete absence of X-Y recombination in males. Despite this, sequences of sex-linked loci show no divergence between the X and Y chromosomes. In the phylogeny, the X and Y alleles cluster according to species, not in groups of gametologs. We conclude that sex-chromosome homomorphy in these tree frogs does not result from a recent turnover but is maintained over evolutionary timescales by occasional X-Y recombination. Seemingly young sex chromosomes may thus carry old-established sex-determining genes, a result at odds with the view that sex chromosomes necessarily decay until they are replaced. This raises intriguing perspectives regarding the evolutionary dynamics of sexually antagonistic genes and the mechanisms that control X-Y recombination.

show abstract

“…In this context, the reasons to focus on H. arborea are twofold. First, documenting the effect of its lek‐breeding mating system on sex‐specific effective sizes should help understanding the dynamics of genetic variance at sex‐specific loci and the evolution of its nascent sex chromosomes (Berset‐Brändli et al 2006, 2007, 2008a; Niculita‐Hirzel et al 2008). Although the proto‐Y chromosome has been shown to display lower levels of standing genetic diversity than does the proto‐X (Berset‐Brändli et al 2007), the difference seems fully accounted for by the numbers of copies per breeding pair (3X vs. 1Y), which appears at odds with the drop in male effective population size expected from its lekking habits (Berset‐Brändli et al 2007).…”

Section: Opportunity For Sexual Selection On Male Mating Success (Ipmentioning

confidence: 99%

OPPORTUNITY FOR SEXUAL SELECTION AND EFFECTIVE POPULATION SIZE IN THE LEK-BREEDING EUROPEAN TREEFROG (HYLA ARBOREA).

2009

View full text Add to dashboard Cite

Sexual selection in lek-breeding species might drastically lower male effective population size, with potentially important consequences for evolutionary and conservation biology. Using field-monitoring and parental-assignment methods, we analyzed sex-specific variances in breeding success in a population of European treefrogs, to (1) help understanding the dynamics of genetic variance at sex-specific loci, and (2) better quantify the risk posed by genetic drift in this species locally endangered by habitat fragmentation. The variance in male mating success turned out to be markedly lower than values obtained from other amphibian species with polygamous mating systems. The ratio of effective breeding size to census breeding size was only slightly lower in males (0.44) than in females (0.57), in line with the patterns of genetic diversity previously reported from H. arborea sex chromosomes. Combining our results with data on age at maturity and adult survival, we show that the negative effect of the mating system is furthermore compensated by the effect of delayed maturity, so that the estimated instantaneous effective size broadly corresponded to census breeding size. We conclude that the lek-breeding system of treefrogs impacts only weakly the patterns of genetic diversity on sex-linked genes and the ability of natural populations to resist genetic drift.

show abstract

Recombination is suppressed and variability reduced in a nascent Y chromosome

Cited by 16 publications

References 40 publications

Cryptic recombination in the ever‐young sex chromosomes of Hylid frogs

Cryptic recombination in the ever‐young sex chromosomes of Hylid frogs

Ever-Young Sex Chromosomes in European Tree Frogs

OPPORTUNITY FOR SEXUAL SELECTION AND EFFECTIVE POPULATION SIZE IN THE LEK-BREEDING EUROPEAN TREEFROG (HYLA ARBOREA).

Contact Info

Product

Resources

About