Cloning and characterization of Bmrunt from the silkworm Bombyx mori during embryonic development
Cloning and characterization of Bmrunt from the silkworm Bombyx mori during embryonic development
复制标题
家蚕胚胎发育过程中 Bmrunt 的克隆和表征
DOI：
10.1002/arch.20261
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发表时间：
2008-10-01
影响因子：
2.2
通讯作者：
Huang, Yongping
中科院分区：
文献类型：
--
作者：
Liu, Wenbin;Yang, Fei;Huang, Yongping
配对规则基因(仅在交替片段中表达的基因，奇数或偶数)在将上游基因的血液梯度转换为双片段周期性对果蝇的身体规划模式起着重要作用。然而，配对规则基因的同源基因在其他昆虫中表现出显著的表达模式和功能的多样性。我们在家蚕中克隆了矮小基因的同源物，家蚕是一种中间的种带型昆虫。整装原位杂交显示，胚胎期原肠形成前有3条纹路相继出现。然后，随着生长区的拉长，依次产生五个额外的条纹。8条条纹以两段周期成对出现，每条条纹局限于一个奇数段的后部。在偶数节段旁出现较弱的节段次生条纹。Bmrunt转录本在胚泡分裂前消失，然后在整个胚胎中重新表达。对Bmrunt的RNA干扰导致严重截断，几乎完全无节段缺陷。这种类似早熟的表型表明Bmrunt在家蚕的分割中不是一个配对规则基因。家蚕大多数体节的形成和轴的伸长都需要Bmrunt。
Pair-rule genes (genes that are expressed only in alternate segments, odd of even) play an important role in translating the blood gradients of upstream genes into dual segment periodicity for body plan patterning in Drosophila. However, homologues of pair-rule genes show a remarkable diversity of expression patterns and functions in other insects. We cloned the homologue of runt in the silkworm Bombyx mori, an intermediate germband-type insect. Whole-mount in situ hybridization revealed three stripes arose one by one before gastrulation at the blastoderm stage. Five additional stripes were then generated sequentially as the growth zone elongated. Eight stripes appeared in a pair-rule manner with two-segment periodicity, each of which was confined to the posterior of an odd-numbered parasegment. The weaker segmental secondary stripes emerged de novo in even-numbered parasegments. The Bmrunt transcript vanished before blastokinesis and was then expressed again in the whole embryo. RNA interference for Bmrunt caused severely truncated, almost completely asegmental defects. This cadual-like phenotype suggests that Bmrunt does not function as a pair-rule gene in silkworm segmentation. Bmrunt is requited for formation of most body segments and axis elongation in B. mori.