The Hmr and Lhr hybrid incompatibility genes suppress a broad range of heterochromatic repeats.
The Hmr and Lhr hybrid incompatibility genes suppress a broad range of heterochromatic repeats.
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DOI：
10.1371/journal.pgen.1004240
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发表时间：
2014-03
期刊：
影响因子：
4.5
通讯作者：
Barbash DA
中科院分区：
文献类型：
--
作者：
Satyaki PR;Cuykendall TN;Wei KH;Brideau NJ;Kwak H;Aruna S;Ferree PM;Ji S;Barbash DA
杂交不相容性（HI）导致物种之间的生殖隔离，从而有助于物种形成。几个HI基因编码适应性进化的蛋白质，定位或与异染色质相互作用，这表明HI可能是由于与快速进化的异染色质DNA的共同进化。然而，人们对这些HI基因的种内功能、它们相互作用的特定序列或驱动它们分化的进化力量知之甚少。Hmr和Lhr基因在遗传上相互作用导致黑腹果蝇和果蝇的杂种致死。然而，这两种基因的突变都是可行的。在这里，我们报告，HMR和LHR编码的蛋白质，形成异染色质蛋白1（HP 1a）的异染色质复合物。使用RNA-Seq分析，我们发现Hmr和Lhr需要抑制来自卫星DNA和许多转座因子（TE）家族的转录物。通过比较D. melanogaster和D.我们鉴定了几个在物种之间差异调节的卫星DNA和TE。Hmr和Lhr突变也导致端粒TEs的大量过度表达和显著的端粒延长。因此，Hmr和Lhr调节三种类型的异染色质序列，这三种异染色质序列负责D. melanogaster和D. simulans，并有很高的潜力，导致遗传冲突与主机健身。我们进一步发现，许多TE在杂交种中过表达，但那些在致死杂交种中特异性错误表达的TE与HMR功能并不密切相关。因此，我们的研究结果认为，适应性分歧的异染色质蛋白质在重复DNA是一个重要的潜在力量驱动杂交不相容基因的进化，但杂交致死性可能会导致新的上位性遗传相互作用，是不同的杂交背景。能够交配的姐妹物种通常会产生不育或在发育过程中死亡的杂种。这种生殖隔离是由两个姐妹物种的基因组之间的不兼容造成的。一些杂交不相容性涉及编码定位于异染色质的快速进化蛋白质的基因。异染色质主要由高度重复的转座因子和卫星DNA组成。据推测，异染色质DNA的快速变化驱动了这些HI基因的变化，从而导致生殖隔离的进化。为了支持这一模型，我们表明，两个快速发展的HI蛋白，Lhr和HMR，这生殖隔离果蝇姐妹种D。melanogaster和D. simulans，抑制转座因子和卫星DNA。这些蛋白质也有助于调节非典型果蝇端粒的长度，而端粒本身是由驯化的转座因子组成的。我们的数据表明，这些蛋白质是适应性机制的一部分，允许宿主对异染色质的变化和增加做出反应，并维持位于异染色质内或附近的基因的活性。
Hybrid incompatibilities (HIs) cause reproductive isolation between species and thus contribute to speciation. Several HI genes encode adaptively evolving proteins that localize to or interact with heterochromatin, suggesting that HIs may result from co-evolution with rapidly evolving heterochromatic DNA. Little is known, however, about the intraspecific function of these HI genes, the specific sequences they interact with, or the evolutionary forces that drive their divergence. The genes Hmr and Lhr genetically interact to cause hybrid lethality between Drosophila melanogaster and D. simulans, yet mutations in both genes are viable. Here, we report that Hmr and Lhr encode proteins that form a heterochromatic complex with Heterochromatin Protein 1 (HP1a). Using RNA-Seq analyses we discovered that Hmr and Lhr are required to repress transcripts from satellite DNAs and many families of transposable elements (TEs). By comparing Hmr and Lhr function between D. melanogaster and D. simulans we identify several satellite DNAs and TEs that are differentially regulated between the species. Hmr and Lhr mutations also cause massive overexpression of telomeric TEs and significant telomere lengthening. Hmr and Lhr therefore regulate three types of heterochromatic sequences that are responsible for the significant differences in genome size and structure between D. melanogaster and D. simulans and have high potential to cause genetic conflicts with host fitness. We further find that many TEs are overexpressed in hybrids but that those specifically mis-expressed in lethal hybrids do not closely correlate with Hmr function. Our results therefore argue that adaptive divergence of heterochromatin proteins in response to repetitive DNAs is an important underlying force driving the evolution of hybrid incompatibility genes, but that hybrid lethality likely results from novel epistatic genetic interactions that are distinct to the hybrid background. Sister species capable of mating often produce hybrids that are sterile or die during development. This reproductive isolation is caused by incompatibilities between the two sister species' genomes. Some hybrid incompatibilities involve genes that encode rapidly evolving proteins that localize to heterochromatin. Heterochromatin is largely made up of highly repetitive transposable elements and satellite DNAs. It has been hypothesized that rapid changes in heterochromatic DNA drives the changes in these HI genes and thus the evolution of reproductive isolation. In support of this model, we show that two rapidly evolving HI proteins, Lhr and Hmr, which reproductively isolate the fruit fly sister species D. melanogaster and D. simulans, repress transposable elements and satellite DNAs. These proteins also help regulate the length of the atypical Drosophila telomeres, which are themselves made of domesticated transposable elements. Our data suggest that these proteins are part of the adaptive machinery that allows the host to respond to changes and increases in heterochromatin and to maintain the activity of genes located within or adjacent to heterochromatin.
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DOI：
10.1155/2012/698198
发表时间：
2012-01-01
期刊：
International journal of evolutionary biology
影响因子：
--
作者：
Castillo, Dean M;Moyle, Leonie C
通讯作者：
Moyle, Leonie C
影响因子：
1.6
作者：
BONACCORSI, S;GATTI, M;LOHE, A
通讯作者：
LOHE, A
DOI：
10.1073/pnas.0702552104
发表时间：
2007-07-03
影响因子：
11.1
作者：
Bergman, Casey M.;Bensasson, Douda
通讯作者：
Bensasson, Douda
影响因子：
3.5
作者：
Baricheva, EA;Berrios, M;Fisher, PA
通讯作者：
Fisher, PA
影响因子：
4
作者：
Andreyeva, EN;Belyaeva, ES;Zhimulev, IF
通讯作者：
Zhimulev, IF