Expression of engrailed-family genes in the jumping bristletail and discussion on the primitive pattern of insect segmentation
Expression of engrailed-family genes in the jumping bristletail and discussion on the primitive pattern of insect segmentation
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DOI：
10.1007/s00427-015-0512-5
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发表时间：
2015-09-01
影响因子：
2.4
通讯作者：
Machida, Ryuichiro
中科院分区：
文献类型：
--
作者：
Nakagaki, Yasutaka;Sakuma, Masashi;Machida, Ryuichiro
已经表明，在短胚昆虫的分割进行两步机制。前部区域以类似于果蝇的方式同时分割，这显然是昆虫所独有的，后部区域的其余部分通过涉及分割时钟的机制顺序分割，该机制来自节肢动物的共同祖先。为了提出昆虫分割的进化方案，我们研究了跳跃的刺尾虫的分割，这是一种几乎现存的昆虫。使用探针的enrailed家庭基因原位杂交，我们发现没有迹象表明，在跳跃的猪鬃胚胎的前部区域的同时分割。除最前面的节段外的所有节段都顺序形成。这种跳跃状态可能代表了昆虫胚胎分裂的原始模式。闰节的插入形成被认为是所有昆虫在跳鬃尾虫分枝后共有的一种突触形态特征。
It has been shown that segmentation in the short-germ insects proceeds by a two-step mechanism. The anterior region is simultaneously segmented in a manner similar to that in Drosophila, which is apparently unique to insects, and the rest of the posterior region is segmented sequentially by a mechanism involving a segmentation clock, which is derived from the common ancestor of arthropods. In order to propose the evolutionary scenario of insect segmentation, we examined segmentation in the jumping bristletail, the basalmost extant insect. Using probes for engrailed-family genes for in situ hybridization, we found no sign of simultaneous segmentation in the anterior region of the jumping bristletail embryos. All segments except the anteriormost segment are formed sequentially. This condition shown in the jumping bristletail embryos may represent the primitive pattern of insect segmentation. The intercalating formation of the intercalary segment is assumed to be a synapomorphic trait shared among all insects after the branching of the jumping bristletail.