Control of distal antennal identity and tarsal development in Drosophila by spineless-aristapedia, a homolog of the mammalian dioxin receptor
Control of distal antennal identity and tarsal development in Drosophila by spineless-aristapedia, a homolog of the mammalian dioxin receptor
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DOI：
10.1101/gad.12.9.1290
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发表时间：
1998-05-01
影响因子：
10.5
通讯作者：
Duncan, I
中科院分区：
文献类型：
--
作者：
Duncan, DM;Burgess, EA;Duncan, I
我们报告的果蝇无刺（SS）基因的分子特征，并提出证据表明，它起着核心作用，在定义的天线和腿的远端区域。ss编码哺乳动物二恶英受体（bHLH-PAS家族的转录因子）的最接近的已知同源物。ss的功能丧失等位基因导致三种主要的表型：末端触角向腿的转化、末端腿（跗）结构的缺失和大多数刚毛尺寸的减小。与这些表型相一致，ss表达在触角成虫盘的远端部分，每个腿盘的跗骨区域，以及刚毛前体细胞中。ss的异位表达导致上颚须和远侧腿向远侧触角的转化，并诱导在吻侧膜中形成异位触角。这些影响表明，ss起着主要作用，在指定远端触角身份。在跗骨中，ss仅在早期表达，并且是跗骨基因bric a brac（bab）的后期表达所必需的。异位表达导致足内侧结构的缺失，表明ss在跗原基的建立中起指导作用。在这两个天线和腿，SS的表达取决于远端（Dll），腹侧附属物形成的主调节器。由ss功能缺失突变引起的触角转化和跗骨缺失可能是返祖的，表明ss在节肢动物肢体远端结构的进化中起着核心作用。
We report the molecular characterization of the spineless (ss) gene of Drosophila, and present evidence that it plays a central role in defining the distal regions of both the antenna and leg. ss encodes the closest known homolog of the mammalian dioxin receptor, a transcription factor of the bHLH-PAS family. Loss-of-function alleles of ss cause three major phenotypes: transformation of distal antenna to leg, deletion of distal leg (tarsal) structures, and reduction in size of most bristles. Consistent with these phenotypes, ss is expressed in the distal portion of the antennal imaginal disc, the tarsal region of each leg disc, and in bristle precursor cells. Ectopic expression of ss causes transformation of the maxillary palp and distal leg to distal antenna, and induces formation of an ectopic antenna in the rostral membrane. These effects indicate that ss plays a primary role in specifying distal antennal identity. In the tarsus, ss is expressed only early, and is required for later expression of the tarsal gene bric a brac (bab). Ectopic expression causes the deletion of medial leg structures, suggesting that ss plays an instructive role in the establishment of the tarsal primordium. In both the antenna and leg, ss expression is shown to depend on Distal-less (Dll), a master regulator of ventral appendage formation. The antennal transformation and tarsal deletions caused by ss loss-of-function mutations are probably atavistic, suggesting that ss played a central role in the evolution of distal structures in arthropod limbs.