A bird’s white-eye view on neosex chromosome evolution
A bird’s white-eye view on neosex chromosome evolution
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新性别染色体进化的鸟瞰图
DOI：
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
B. Nabholz
中科院分区：
文献类型：
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作者：
Thibault Leroy;Yoann Anselmetti;Marie;S. Bérard;Laura Csukonyi;Maëva Gabrielli;Céline Scornavacca;B. Milá;C. Thébaud;B. Nabholz
这篇文章已经过同行评审，并由Peer Community In EvolutionaryBiology推荐。
鸟类的染色体结构相对稳定，特别是性染色体。然而，大型Sylvioidea进化枝的成员具有一对新性染色体，这对新性染色体是该进化枝所特有的，并且起源于W和Z染色体上的祖先4A染色体的一个区域的平行易位。在这里，我们利用这一不寻常的事件来研究性染色体进化的早期阶段。为了做到这一点，我们对两个森林总科物种的雌性（ZW）进行了测序，一个是Zosterops borbonicus，另一个是Z。苍白球然后，我们组织了Z。borbonicus支架沿着染色体和注释基因。根据各种方法和校准集进行的分子系统发育年代测定确信地证实了Zosterops属最近的多样化（1- 350万年前），因此代表了脊椎动物中最特殊的多样化率之一。然后，我们结合基因组覆盖率比较5名男性和7名女性，并与斑马雀基因组（Taeniopygia guttata）的同源性，以确定性染色体支架，以及两个易位事件的候选染色体断点。我们观察到两个易位区域的物种内多样性水平降低，正如预期的那样，在neoW染色体上更是如此。为了比较常染色体到性别转换的基因组区域中的分子进化速率，我们然后估计了非同义与同义多态性（πN/πS）和替换（dN/dS）的比率。基于这两个比率，在常染色体和Z基因之间没有观察到或观察到很少的对比，因此代表了与在neoW基因处观察到的较高比率非常不同的结果。此外，我们报告的W和Z染色体上的易位区域的碱基组成内容的显着变化和大量积累的转座因子（TE）的新的W区域。我们的研究结果揭示了与这些常染色体到性染色体转换相关的分子进化变化的对比信号，W染色体变性的一致信号对快速Z效应的支持令人惊讶地微弱。
This article has been peer-reviewed and recommended by Peer Community In EvolutionaryBiology.
Chromosomal organization is relatively stable among avian species, especially with regards to sex chromosomes. Members of the large Sylvioidea clade however have a pair of neo-sex chromosomes which is unique to this clade and originate from a parallel translocation of a region of the ancestral 4A chromosome on both W and Z chromosomes. Here, we took advantage of this unusual event to study the early stages of sex chromosome evolution. To do so, we sequenced a female (ZW) of two Sylvioidea species, a Zosterops borbonicus and a Z. pallidus. Then, we organized the Z. borbonicus scaffolds along chromosomes and annotated genes. Molecular phylogenetic dating under various methods and calibration sets confidently confirmed the recent diversification of the genus Zosterops (1-3.5 million years ago), thus representing one of the most exceptional rates of diversification among vertebrates. We then combined genomic coverage comparisons of five males and seven females, and homology with the zebra finch genome (Taeniopygia guttata) to identify sex chromosome scaffolds, as well as the candidate chromosome breakpoints for the two translocation events. We observed reduced levels of within-species diversity in both translocated regions and, as expected, even more so on the neoW chromosome. In order to compare the rates of molecular evolution in genomic regions of the autosomal-to-sex transitions, we then estimated the ratios of non-synonymous to synonymous polymorphisms (πN/πS) and substitutions (dN/dS). Based on both ratios, no or little contrast between autosomal and Z genes was observed, thus representing a very different outcome than the higher ratios observed at the neoW genes. In addition, we report significant changes in base composition content for translocated regions on the W and Z chromosomes and a large accumulation of transposable elements (TE) on the newly W region. Our results revealed contrasted signals of molecular evolution changes associated to these autosome-to-sex chromosome transitions, with congruent signals of a W chromosome degeneration yet a surprisingly weak support for a fast-Z effect.
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影响因子：
7
作者：
Zimin AV;Puiu D;Luo MC;Zhu T;Koren S;Marçais G;Yorke JA;Dvořák J;Salzberg SL
通讯作者：
Salzberg SL
影响因子：
10.7
作者：
B. Nabholz;Axel Künstner;Rui Wang;E. Jarvis;H. Ellegren
通讯作者：
B. Nabholz;Axel Künstner;Rui Wang;E. Jarvis;H. Ellegren
影响因子：
64.8
作者：
Jetz, W.;Thomas, G. H.;Mooers, A. O.
通讯作者：
Mooers, A. O.
影响因子：
14.9
作者：
Haas, BJ;Delcher, AL;White, O
通讯作者：
White, O
影响因子：
4.1
作者：
Bernt, Matthias;Donath, Alexander;Stadler, Peter F.
通讯作者：
Stadler, Peter F.