Limited gene misregulation is exacerbated by allele-specific upregulation in lethal hybrids between Drosophila melanogaster and Drosophila simulans.
Limited gene misregulation is exacerbated by allele-specific upregulation in lethal hybrids between Drosophila melanogaster and Drosophila simulans.
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DOI：
10.1093/molbev/msu127
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发表时间：
2014-07
影响因子：
10.7
通讯作者：
K. Wei;A. Clark;D. Barbash
中科院分区：
文献类型：
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作者：
K. Wei;A. Clark;D. Barbash
在种间杂交中经常观察到基因表达的调控错误，通常归因于两个基因组之间的分化引起的调控不相容。然而，将调控差异效应与杂交种常见的发育和生理缺陷等次生效应区分开来一直是一项挑战。在这里，我们使用RNA-Seq分析了黑腹果蝇（Drosophila melanogaster）与其兄弟种拟象果蝇（d.s simulans）杂交的F1杂交雄性幼虫的基因表达。我们分析了致命的和有活力的杂交雄性，后者是使用x连锁的D. melanogaster杂交雄性拯救（Hmr）基因突变产生的，并将它们与亲本物种以及发育过程中基因表达的公共数据集进行了比较。我们发现Hmr对亲本和杂交种基因组的影响截然不同，表明杂交种不亲和性基因在杂交种遗传背景下可以表现出新的特性。此外，我们发现黑腹田鼠等位基因在致死性和活性杂交种之间优先受影响。我们进一步确定杂交种之间的许多差异是由Hmr（+）杂交种的发育延迟引起的。最后，我们发现与亲本相比，杂交种的表达差异出奇地小，分别只有9%和4%的基因偏离了可加性或在亲本范围之外表达。这些差异大多可归因于发育迟缓和组织类型的差异。总的来说，我们的研究表明，杂交基因的错误表达容易被高估，即使在相隔约2.5 Ma的物种之间，调节不相容在杂交中也不普遍。
Misregulation of gene expression is often observed in interspecific hybrids and is generally attributed to regulatory incompatibilities caused by divergence between the two genomes. However, it has been challenging to distinguish effects of regulatory divergence from secondary effects including developmental and physiological defects common to hybrids. Here, we use RNA-Seq to profile gene expression in F1 hybrid male larvae from crosses of Drosophila melanogaster to its sibling species D. simulans. We analyze lethal and viable hybrid males, the latter produced using a mutation in the X-linked D. melanogaster Hybrid male rescue (Hmr) gene and compare them with their parental species and to public data sets of gene expression across development. We find that Hmr has drastically different effects on the parental and hybrid genomes, demonstrating that hybrid incompatibility genes can exhibit novel properties in the hybrid genetic background. Additionally, we find that D. melanogaster alleles are preferentially affected between lethal and viable hybrids. We further determine that many of the differences between the hybrids result from developmental delay in the Hmr(+) hybrids. Finally, we find surprisingly modest expression differences in hybrids when compared with the parents, with only 9% and 4% of genes deviating from additivity or expressed outside of the parental range, respectively. Most of these differences can be attributed to developmental delay and differences in tissue types. Overall, our study suggests that hybrid gene misexpression is prone to overestimation and that even between species separated by approximately 2.5 Ma, regulatory incompatibilities are not widespread in hybrids.