Vulva morphogenesis involves attraction of plexin 1-expressing primordial vulva cells to semaphorin 1a sequentially expressed at the vulva midline
Vulva morphogenesis involves attraction of plexin 1-expressing primordial vulva cells to semaphorin 1a sequentially expressed at the vulva midline
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DOI：
10.1242/dev.01694
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发表时间：
2005-03-01
期刊：
影响因子：
4.6
通讯作者：
Culotti, JG
中科院分区：
文献类型：
--
作者：
Dalpé, G;Brown, L;Culotti, JG
线虫的外阴发育涉及细胞命运规范，随后是形态发生阶段，其中原始外阴细胞线性阵列内的同源镜像对在它们顺序地移向阵列内的中线位置时形成新月形状。来自另一半外阴的同源对以固定的顺序在其前导尖端彼此融合，形成环形（环形）细胞，这些细胞以精确的排列方式堆叠在一起。在这里，我们表明，同源外阴细胞对向中线位置移动需要信号蛋白 la SMP-1 及其丛蛋白受体 PLX-1。当SMP-1进入正在形成的外阴时，SMP-1在每个原始外阴细胞的管腔膜上被上调，并且显然将下一个侧翼的表达PLX-1的同源外阴细胞吸引到环的管腔表面。因此，一个新的环形细胞紧邻先前形成的环的腹侧形成。这种依赖于 smp-1 和 plx-1 的过程不断重复，直到七个环沿着背腹轴堆叠，形成一个共同的外阴腔。 SMP-1 的异位表达表明它在外阴细胞迁移中具有指导作用。外阴形成至少需要两条平行作用途径：一条需要SMP-1、PLX-1和CED-10；另一条需要SMP-1、PLX-1和CED-10。另一个需要 MIG-2 Rac GTPase 及其假定的激活剂 UNC-73。
Vulva development in C elegans involves cell fate specification followed by a morphogenesis phase in which homologous mirror image pairs within a linear array of primordial vulva cells form a crescent shape as they move sequentially towards a midline position within the array. The homologous pairs from opposite half vulvae in fixed sequence fuse with one another at their leading tips to form ring-shaped (toroidal) cells stacked in precise alignment one atop the other. Here, we show that the semaphorin la SMP-1, and its plexin receptor PLX-1, are required for the movement of homologous pairs of vulva cells towards this midline position. SMP-1 is upregulated on the lumen membrane of each primordial vulva cell as it enters the forming vulva and apparently attracts the next flanking homologous PLX-1-expressing vulva cells towards the lumen surface of the ring. Consequently, a new ring-shaped cell forms immediately ventral to the previously formed ring. This smp-1- and plx-1-dependent process repeats until seven rings are stacked along the dorsoventral axis, creating a common vulva lumen. Ectopic expression of SMP-1 suggests it has an instructive role in vulva cell migration. At least two parallel acting pathways are required for vulva formation: one requires SMP-1, PLX-1 and CED-10; and another requires the MIG-2 Rac GTPase and its putative activator UNC-73.