The Drosophila embryonic patterning determinant torsolike is a component of the eggshell
The Drosophila embryonic patterning determinant torsolike is a component of the eggshell
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DOI：
10.1016/s0960-9822(03)00379-8
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发表时间：
2003-06-17
期刊：
影响因子：
9.2
通讯作者：
Stein, D
中科院分区：
文献类型：
--
作者：
Stevens, LM;Beuchle, D;Stein, D
果蝇胚胎头部和尾部的发育依赖于躯干(Tor)的局部极化激活，Tor是一种均匀分布在发育中的胚胎膜上的受体酪氨酸激酶[1，2]。Trk(Trk)，被建议的Tor的配基，作为一种不活跃的前体分泌到位于胚胎膜和卵黄膜(Vm)之间的卵黄周液中，卵黄膜是蛋壳的内层[3，4]。Trk加工的空间调节被认为是由Torsolike(TSL)基因的分泌产物介导的，TSL基因在卵子发生过程中由位于卵母细胞两端的一组特殊的滤泡细胞表达[5，6]。我们在这里展示了TSL蛋白在产卵中特异性地定位于Vm的极区。我们进一步证明，尽管TSL可以与Vm的非极区联系，但极性定位的TSL的活性被增强，这表明在这一途径中存在另一个空间受限因素。TSL被整合到Vm中，为空间信息从卵泡细胞转移到发育中的胚胎提供了一种机制。据我们所知，TSL代表了第一个胚胎模式决定簇的例子，它是蛋壳的一个组成部分。
The development of the head and tail regions of the Drosophila embryo is dependent upon the localized polar activation of Torso (Tor), a receptor tyrosine kinase that is uniformly distributed in the membrane of the developing embryo [1, 2]. Trunk (Trk), the proposed ligand for Tor, is secreted as an inactive precursor into the perivitelline fluid that lies between the embryonic membrane and the vitelline membrane (VM), the inner layer of the eggshell [3,4]. The spatial regulation of Trk processing is thought to be mediated by the secreted product of the torsolike (tsl) gene, which is expressed during oogenesis by a specialized population of follicle cells present at the two ends of the oocyte [5, 6]. We show here that Tsl protein is specifically localized to the polar regions of the VM in laid eggs. We further demonstrate that although Tsl can associate with non-polar regions of the VM, the activity of polar-localized Tsl is enhanced, suggesting the existence of another spatially restricted factor acting in this pathway. The incorporation of Tsl into the VM provides a mechanism for the transfer of spatial information from the follicle cells to the developing embryo. To our knowledge, Tsl represents the first example of an embryonic patterning determinant that is a component of the eggshell.