A comparative genomic analysis of targets of Hox protein Ultrabithorax amongst distant insect species.
A comparative genomic analysis of targets of Hox protein Ultrabithorax amongst distant insect species.
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DOI：
10.1038/srep27885
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发表时间：
2016-06-14
影响因子：
4.6
通讯作者：
Shashidhara LS
中科院分区：
文献类型：
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作者：
Prasad N;Tarikere S;Khanale D;Habib F;Shashidhara LS
在黑腹果蝇中，翅膀和胸部的差异发育取决于Hox蛋白超胸腺（Ubx）的功能。本研究比较了ubx介导的蜜蜂、蜜蜂、家蚕和果蝇对翅膀图案基因的调控。Ubx的同源基因在Apis和家蚕的第三胸段表达，尽管它们是功能性的后翼。当在转基因果蝇中过表达时，来自api或家蚕的Ubx可以抑制翅膀发育，这表明Ubx在辅助因子和/或靶点水平上发生了进化变化。为了进一步了解这些事件，我们通过ChIP-seq从api和Bombyx中鉴定了Ubx的直接靶点，并将其与果蝇进行了比较。虽然大多数假定的Ubx靶点都是物种特异性的，但在过去的3亿年里，相当数量的翅膀模式基因被保留下来，作为这三个物种的靶点。有趣的是，许多这些基因仅在果蝇的翅和肢端之间有差异表达，而在Apis或家蚕的前翅和后翅之间没有差异表达。增强子序列的详细生物信息学和实验验证表明，可能与其他因素一起，早期靶点顺式调控序列的变化有助于Ubx功能的多样性。
In the fruitfly Drosophila melanogaster, the differential development of wing and haltere is dependent on the function of the Hox protein Ultrabithorax (Ubx). Here we compare Ubx-mediated regulation of wing patterning genes between the honeybee, Apis mellifera, the silkmoth, Bombyx mori and Drosophila. Orthologues of Ubx are expressed in the third thoracic segment of Apis and Bombyx, although they make functional hindwings. When over-expressed in transgenic Drosophila, Ubx derived from Apis or Bombyx could suppress wing development, suggesting evolutionary changes at the level of co-factors and/or targets of Ubx. To gain further insights into such events, we identified direct targets of Ubx from Apis and Bombyx by ChIP-seq and compared them with those of Drosophila. While majority of the putative targets of Ubx are species-specific, a considerable number of wing-patterning genes are retained, over the past 300 millions years, as targets in all the three species. Interestingly, many of these are differentially expressed only between wing and haltere in Drosophila but not between forewing and hindwing in Apis or Bombyx. Detailed bioinformatics and experimental validation of enhancer sequences suggest that, perhaps along with other factors, changes in the cis-regulatory sequences of earlier targets contribute to diversity in Ubx function.