Trunk segment numbers and sequential segmentation in myriapods
Trunk segment numbers and sequential segmentation in myriapods
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DOI：
10.1111/j.1525-142x.2005.05064.x
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发表时间：
2005-11-01
影响因子：
2.9
通讯作者：
Fusco, G
中科院分区：
文献类型：
--
作者：
Fusco, G
节肢动物后方“增殖区”的连续分割被认为是节肢动物分割的原始机制。一些关于胚胎和胚胎后发育和基因表达的研究表明，这在所有主要的节肢动物分类群中都存在。顺序分割通常与沿着主体轴累积的身体单元的后部产生的想法相关联。然而，序列分割的确切机制还没有确定，在寻找能够在胚胎中产生第一周期模式的遗传电路的同时，我们至少可以概述在增殖区分割中的独特作用。对多足类片段模式的研究表明，这些模式是多层发育过程的结果，在这些过程中，基因表达和表观遗传机制以一种非严格的层级方式相互作用。后部区域可能是周期性信号产生的区域，但一般而言，所产生的节段性模式并不完全归因于信号发生器的活动。从这个意义上说，后部增殖带更像是“节段性组织者”，而不是“节段性生成器”。
Sequential segmentation from a posterior "proliferative zone" is considered to be the primitive mechanism of segmentation in arthropods. Several studies of embryonic and post-embryonic development and gene expression suggest that this occurs in all major arthropod taxa. Sequential segmentation is often associated with the idea of posterior production of body units that accumulate along the main body axis. However, the precise mechanism of sequential segmentation has not been identified yet, and, while searching for the genetic circuitry able to generate a first periodic pattern in the embryo, we can at least outline the distinctive role in segmentation of a proliferative zone. A perusal of myriapod segmentation patterns suggests that these patterns result from multi-layered developmental processes, where gene expression and epigenetic mechanisms interact in a nonstrictly hierarchical way. The posterior zone is possibly a zone of periodic signal production, but, in general, the resulting segmental pattern is not completely attributable to the activity of the signal generator. In this sense, a posterior proliferative zone would be more a "segmental organizer" than a "segment generator."