The role of the pupal determinant broad during embryonic development of a direct-developing insect.
The role of the pupal determinant broad during embryonic development of a direct-developing insect.
复制标题
DOI：
10.1007/s00427-009-0315-7
复制
发表时间：
2009-12
影响因子：
2.4
通讯作者：
Riddiford LM
中科院分区：
文献类型：
--
作者：
Erezyilmaz DF;Rynerson MR;Truman JW;Riddiford LM
变形是生命史上最常见但又最引人注目的策略之一。在昆虫中，具有形态上不同的幼虫阶段的完全变态起源于更直接发育的半变态祖先。在过去的世纪里，出现了几种观点，认为全变态蛹与半变态祖先的胚胎阶段在发育上同源。其他理论认为蛹期是半变态若虫的一种变异。为了解决这个问题，我们已经分离出一个直系同源的蛹的决定因素，广泛（br），从hemimetamedous马利筋错误，并检查其在胚胎发育过程中的作用。我们发现Oncopeltus fasciatus br（Of'br）的表达分两个阶段。第一个发生在胚带内陷和分割过程中，此时Of'br在胚胎组织中普遍表达。Of'br表达的第二阶段出现在胚胎发生的原若虫阶段，并持续通过若虫分化，直到孵化前下降。敲低Of'br转录物导致的缺陷范围从受影响最小的表型中的后截短到最严重情况下的完全破碎的胚胎组织。模式化基因的分析显示，在Ofbr耗尽后，节段的丢失和神经分化的失败。最后，我们表明，br是组成型表达的胚胎发育过程中的ametabolous firebrat，Thermobia astritica。这表明，br的表达是突出的胚胎发育过程中的无变态和半变态昆虫，但失去了出现的完全变态昆虫。
Metamorphosis is one of the most common, yet dramatic of life history strategies. In insects, complete metamorphosis with morphologically distinct larval stages arose from hemimetabolous ancestors that were more direct developing. Over the past century, several ideas have emerged that suggest the holometabolous pupa is developmentally homologous to the embryonic stages of the hemimetabolous ancestor. Other theories consider the pupal stage to be a modification of a hemimetabolous nymph. To address this question, we have isolated an ortholog of the pupal determinant, broad (br), from the hemimetabolous milkweed bug and examined its role during embryonic development. We show that Oncopeltus fasciatus br (Of'br) is expressed in two phases. The first occurs during germ band invagination and segmentation when Of'br is expressed ubiquitously in the embryonic tissues. The second phase of Of'br expression appears during the pronymphal phase of embryogenesis and persists through nymphal differentiation to decline just before hatching. Knock-down of Of'br transcripts results in defects that range from posterior truncations in the least-affected phenotypes to completely fragmented embryonic tissues in the most severe cases. Analysis of the patterning genes engrailed and hunchback reveal loss of segments and a failure in neural differentiation after Of'br depletion. Finally, we show that br is constitutively expressed during embyrogenesis of the ametabolous firebrat, Thermobia domestica. This suggests that br expression is prominent during embryonic development of ametabolous and hemimetabolous insects but was lost with the emergence of the completely metamorphosing insects.
登录
查看更多内容
影响因子：
2.2
作者：
LAGUEUX, M;HETRU, C;HOFFMANN, JA
通讯作者：
HOFFMANN, JA
影响因子：
4.6
作者：
Liu, PZ;Kaufman, TC
通讯作者：
Kaufman, TC
影响因子：
2.6
作者：
DORN, A;HOFFMANN, P
通讯作者：
HOFFMANN, P
影响因子：
4.6
作者：
Liu, PZ;Kaufman, TC
通讯作者：
Kaufman, TC
影响因子：
4.6
作者：
Liu, PZ;Kaufman, TC
通讯作者：
Kaufman, TC