Soldier differentiation during embryogenesis of a social aphid, Pseudoregma bambucicola
Soldier differentiation during embryogenesis of a social aphid, Pseudoregma bambucicola
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DOI：
10.1111/j.1479-8298.2004.00061.x
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发表时间：
2004-06-01
影响因子：
0.9
通讯作者：
Fukatsu, T
中科院分区：
文献类型：
--
作者：
Ijichi, N;Shibao, H;Fukatsu, T
为了解蚜虫兵虫分化的发育过程，研究了小兵蚜正常若虫、兵虫若虫和发育胚的形态特征。形态计量学分析结果表明，正常和士兵若虫在几种形态特征的基础上形成了离散的集群，尽管存在少量中间个体，称为“跨种若虫”。在胚胎后期，正常胚胎和士兵胚胎在形态上是可区分的。胚胎阶段越早，它们之间的形态差异越小。在长度小于1000母的早期胚胎中，正常胚胎和兵胚在形态上无法区分，这表明兵胚分化发生在早期胚胎阶段。在整个胚胎发育过程中，士兵种姓的形态分化是逐渐进行的。值得注意的是，在幼虫期，士兵的一些形态特征显著增长。对胚胎腿角质层的观察显示出典型的折叠结构，表明战士的一些形态特征在幼虫期通过折叠角质层的扩大而被夸大。结果表明，小兵阶层的形态分化分为两个阶段：胚胎发育阶段的逐渐生长阶段和幼虫发育阶段的快速生长阶段。
To understand the developmental process of aphid soldier differentiation, we investigated the morphological characters of normal nymphs, soldier nymphs and developing embryos of Pseudoregma bambucicola. Results of morphometric analyses showed that normal and soldier nymphs formed discrete clusters on the basis of several morphological characters, although a small number of intermediate individuals, termed 'intercaste nymphs', were present. In late embryonic stages, normal and soldier embryos were morphologically distinguishable. The earlier the embryonic stage, the smaller the morphological differences between them. In early embryos less than 1000 mum in length, normal and soldier embryos were not morphologically distinguishable, suggesting that the onset of soldier differentiation occurs at an early embryonic stage. Throughout embryonic development, morphological differentiation of the soldier caste proceeded gradually. Notably, several morphological characters of soldiers grew remarkably upon larviposition. Observation of embryonic leg cuticle revealed a characteristic folding structure, indicating that some morphological traits of the soldier are exaggerated upon larviposition through expansion of the folded cuticle. We suggest that morphological differentiation of the soldier caste in P. bambucicola comprises two phases: gradual growth during embryogenesis and rapid growth upon larviposition.