Muscles in the Drosophila second thoracic segment are patterned independently of autonomous homeotic gene function
Muscles in the Drosophila second thoracic segment are patterned independently of autonomous homeotic gene function
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DOI：
10.1016/s0960-9822(06)00117-5
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发表时间：
1997-04-01
期刊：
影响因子：
9.2
通讯作者：
VijayRaghavan, K
中科院分区：
文献类型：
--
作者：
Roy, S;Shashidhara, LS;VijayRaghavan, K
背景：在果蝇中，节段特异性肌肉模式被认为是由中胚层同源选择基因的自主功能结合来自发育中的表皮和神经系统的诱导信号决定的。在这里，我们研究了同源基因在果蝇胸节体肌模式形成中的作用。结果：我们确定了胚胎和成体发育过程中胸节中胚层中同源蛋白的表达模式。我们发现，与分别表达性别梳减少和触角足（Antp）的第一和第三胸节的中胚层不同，第二胸节的中胚层不表达任何已知的Antp或bithorax复合体的同源选择基因。在 Antp 无效突变纯合的动物中，第二胸节的肌肉在胚胎中受到影响，这可能是其在外胚层中的需求的间接结果。中胚层特别缺乏 Antp 功能，但在表皮表达该基因的动物，在第二胸段发育出正常的肌肉模式。此外，第二胸节中胚层中 Antp 和其他同源选择基因的特异性异位表达重新指定了其肌肉模式，表明这些基因在该节段的肌肉发育过程中并不是自主需要的。最后，我们发现 Antp 继续在“四翅果蝇”同源转化的第三胸节的中胚层中表达，并表明这可能是转化节段中飞行肌发育失败的原因。结论：我们提出了第二胸节肌肉发育的模型，其中中胚层特性完全通过诱导来确定，与其他节段的肌肉发育相反，其他节段的肌肉发育也需要同源选择基因的自主功能。 (C) 当前生物有限公司
Background: In Drosophila, segment-specific muscle pattern is thought to be determined by the autonomous function of homeotic selector genes in the mesoderm in combination with inductive cues from the developing epidermis and nervous system. Here, we have examined the roles of homeotic genes in the patterning of the somatic muscles of the thoracic segments of Drosophila.Results: We determined the expression patterns of homeoproteins in the mesoderm of the thoracic segments during embryonic and adult development. We found that, unlike the mesoderm of the first and third thoracic segments which express Sex combs reduced and Antennapedia (Antp), respectively, the mesoderm of the second thoracic segment does not express any known homeotic selector gene of the Antp or bithorax complex. In animals homozygous for Antp null mutations, the muscles of the second thoracic segment were affected in the embryo, probably as an indirect consequence of its requirement in the ectoderm. Animals that specifically lacked Antp function in the mesoderm, but expressed the gene in the epidermis, developed with a normal muscle pattern in the second thoracic segment. Furthermore, specific ectopic expression of Antp and other homeotic selector genes in the mesoderm of the second thoracic segment respecified its muscle pattern, indicating that these genes are not required autonomously during muscle development in this segment. Finally, we showed that Antp continues to be expressed in the mesoderm of the homeotically transformed third thoracic segment in the 'four-winged fly', and suggest that this is a likely reason for the failure of flight muscle development in the transformed segment.Conclusions: We present a model for muscle development in the second thoracic segment whereby mesodermal properties are specified entirely by induction, in contrast to muscle development in other segments, where autonomous function for homeotic selector genes is also required. (C) Current Biology Ltd.