Amoebozoans Are Secretly but Ancestrally Sexual: Evidence for Sex Genes and Potential Novel Crossover Pathways in Diverse Groups of Amoebae.
Amoebozoans Are Secretly but Ancestrally Sexual: Evidence for Sex Genes and Potential Novel Crossover Pathways in Diverse Groups of Amoebae.
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变形虫是秘密但祖先有性的：不同变形虫群体中性基因和潜在新交叉途径的证据。
DOI：
10.1093/gbe/evx002
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发表时间：
2017
影响因子：
3.3
通讯作者：
Gorfu,LydiaA
中科院分区：
文献类型：
--
作者：
Tekle,YonasI;Wood,FionaC;Katz,LauraA;Cerón-Romero,MarioA;Gorfu,LydiaA
性在真核生物中是有益的，因为它可以增加遗传多样性，重组基因组，清除有害的突变。然而，它的进化仍然是一个谜。真核生物进化枝超类群变形虫包括多种多样的多形变形虫形式的谱系，包括自由生活和寄生谱系。这个群体通常被认为是无性的，尽管最近的研究表明，它的一些成员与神秘形式的性周期有关。在这项研究中，我们进行了全面的清单和分析基因参与减数分裂和相关过程，以探讨进化史的性别在分支。我们分析了39变形虫的基因组和转录组数据，代表所有主要分支的变形虫。研究结果表明，阿米巴原虫具有大部分减数分裂基因，但缺乏联会复合体（SC）编码基因。SC基因的情况下进行了讨论的背景下，早期的研究报告SC的超微结构证据在一些阿米巴。我们还发现了性基因分布的分支间和属内变异，表明该组中性途径的多样性。特别是，Mycetozoa的成员参与了一种新的性途径，独立于普遍保守的减数分裂起始基因SPO11。我们的研究结果有力地表明，变形虫不仅在其基因组中具有性基因，而且，基于转录组证据，目前的性基因是功能性的。我们的结论是，阿米巴原虫是祖先的性，相反，长期以来认为，它的大多数成员是无性的。因此，如果阿米巴虫的无性生殖被证实存在的话，那么它就是一种在进化后期出现的衍生特征。
Sex is beneficial in eukaryotes as it can increase genetic diversity, reshuffle their genomes, and purge deleterious mutations. Yet, its evolution remains a mystery. The eukaryotic clade supergroup Amoebozoa encompasses diverse lineages of polymorphic amoeboid forms, including both free-living and parasitic lineages. The group is generally believed to be asexual, though recent studies show that some of its members are implicated in cryptic forms of sexual cycles. In this study, we conduct a comprehensive inventory and analysis of genes involved in meiosis and related processes, in order to investigate the evolutionary history of sex in the clade. We analyzed genomic and transcriptomic data of 39 amoebozoans representing all major subclades of Amoebozoa. Our results show that Amoebozoa possess most of the genes exclusive to meiosis but lack genes encoding synaptonemal complex (SC). The absence of SC genes is discussed in the context of earlier studies that reported ultrastructural evidence of SC in some amoebae. We also find interclade and intrageneric variation in sex gene distribution, indicating diversity in sexual pathways in the group. Particularly, members of Mycetozoa engage in a novel sexual pathway independent of the universally conserved meiosis initiator gene,SPO11. Our findings strongly suggest that not only do amoebozoans possess sex genes in their genomes, but also, based on the transcriptome evidence, the present sex genes are functional. We conclude that Amoebozoa is ancestrally sexual, contrary to the long held belief that most of its members are asexual. Thus, asexuality in Amoebozoa, if confirmed to be present, is a derived-trait that appeared later in their evolution.
影响因子：
4.3
作者：
H. Sambrook
通讯作者：
H. Sambrook