Asaoka-Taguchi M, Yamada M, Nakamura A, Hanyu K, Kobayashi S
Institute of Biological Sciences, University of Tsukuba, Ten-noudai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan.
Nat Cell Biol. 1999 Nov;1(7):431-7. doi: 10.1038/15666.
The maternal RNA-binding proteins Pumilio (Pum) and Nanos (Nos) act together to specify the abdomen in Drosophila embryos. Both proteins later accumulate in pole cells, the germline progenitors. Nos is required for pole cells to differentiate into functional germline. Here we show that Pum is also essential for germline development in embryos. First, a mutation in pum causes a defect in pole-cell migration into the gonads. Second, in such pole cells, the expression of a germline-specific marker (PZ198) is initiated prematurely. Finally, pum mutation causes premature mitosis in the migrating pole cells. We show that Pum inhibits pole-cell division by repressing translation of cyclin B messenger RNA. As these phenotypes are indistinguishable from those produced by nos mutation, we conclude that Pum acts together with Nos to regulate these germline-specific events.
母体RNA结合蛋白Pumilio（Pum）和Nanos（Nos）共同作用，决定果蝇胚胎的腹部特征。这两种蛋白随后都会在极细胞（生殖系祖细胞）中积累。Nos是极细胞分化为功能性生殖系所必需的。在此我们表明，Pum对胚胎中的生殖系发育也至关重要。首先，pum中的一个突变导致极细胞向性腺迁移出现缺陷。其次，在这类极细胞中，生殖系特异性标记物（PZ198）的表达过早开始。最后，pum突变导致迁移中的极细胞过早进行有丝分裂。我们表明，Pum通过抑制细胞周期蛋白B信使核糖核酸的翻译来抑制极细胞分裂。由于这些表型与nos突变产生的表型无法区分，我们得出结论，Pum与Nos共同作用来调节这些生殖系特异性事件。
