Short germ insects utilize both the ancestral and derived mode of Polycomb group-mediated epigenetic silencing of Hox genes.
Short germ insects utilize both the ancestral and derived mode of Polycomb group-mediated epigenetic silencing of Hox genes.
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DOI：
10.1242/bio.201411064
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发表时间：
2015-05-06
期刊：
影响因子：
2.4
通讯作者：
Mito T
中科院分区：
文献类型：
--
作者：
Matsuoka Y;Bando T;Watanabe T;Ishimaru Y;Noji S;Popadić A;Mito T
在经历长胚芽分割的昆虫物种中，如果蝇，所有的片段在早期胚盘阶段同时被指定。随着胚胎发生的进展，Hox基因的表达边界是由gap基因的抑制建立的，随后被Polycomb组（PcG）沉默所取代。然而，目前尚不清楚是否在胚胎发生的更原始（短胚芽）模式中以这种方式发生图案化，其中片段在后部延伸期间逐渐增加。在这项研究中，两个成员的PcG家族，增强子的zeste（E（z））和抑制子的zeste 12（苏（z）12），在短胚芽蟋蟀，Gryllus bimaculatus进行了分析。结果表明，虽然间隙和PcG基因的逐步负调控存在于前成员的Hox集群，它不占两个后Hox基因，腹-A（abd-A）和腹-B（Abd-B）的调节。相反，Abd-A和Abd-B主要由PcG基因调控，这是脊椎动物中存在的模式。这些发现表明，一个有趣的过渡PcG介导的沉默的Hox基因可能发生在动物进化过程中。祖先的两侧对称状态可能类似于目前的脊椎动物的调控模式，其中PcG介导的Hox基因沉默发生在它们的表达开始之前，并负责建立单独的表达结构域。在昆虫进化过程中，短胚昆虫的前部Hox基因可能获得了转录因子的抑制，而后部Hox基因则保持了PcG沉默。
In insect species that undergo long germ segmentation, such as Drosophila, all segments are specified simultaneously at the early blastoderm stage. As embryogenesis progresses, the expression boundaries of Hox genes are established by repression of gap genes, which is subsequently replaced by Polycomb group (PcG) silencing. At present, however, it is not known whether patterning occurs this way in a more ancestral (short germ) mode of embryogenesis, where segments are added gradually during posterior elongation. In this study, two members of the PcG family, Enhancer of zeste (E(z)) and Suppressor of zeste 12 (Su(z)12), were analyzed in the short germ cricket, Gryllus bimaculatus. Results suggest that although stepwise negative regulation by gap and PcG genes is present in anterior members of the Hox cluster, it does not account for regulation of two posterior Hox genes, abdominal-A (abd-A) and Abdominal-B (Abd-B). Instead, abd-A and Abd-B are predominantly regulated by PcG genes, which is the mode present in vertebrates. These findings suggest that an intriguing transition of the PcG-mediated silencing of Hox genes may have occurred during animal evolution. The ancestral bilaterian state may have resembled the current vertebrate mode of regulation, where PcG-mediated silencing of Hox genes occurs before their expression is initiated and is responsible for the establishment of individual expression domains. Then, during insect evolution, the repression by transcription factors may have been acquired in anterior Hox genes of short germ insects, while PcG silencing was maintained in posterior Hox genes.
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DOI：
10.1016/j.cub.2009.01.052
发表时间：
2009-03-10
期刊：
Current biology : CB
影响因子：
--
作者：
Martin BL;Kimelman D
通讯作者：
Kimelman D
影响因子：
64.8
作者：
Agger, Karl;Cloos, Paul A. C.;Helin, Kristian
通讯作者：
Helin, Kristian
影响因子：
56.9
作者：
Lee, Min Gyu;Villa, Raffaella;Shiekhattar, Ramin
通讯作者：
Shiekhattar, Ramin
影响因子：
2.7
作者：
Mito, Taro;Okamoto, Haruko;Noji, Sumihare
通讯作者：
Noji, Sumihare
影响因子：
8
作者：
Jaeger, Johannes
通讯作者：
Jaeger, Johannes