The establishment of Caenorhabditis elegans germline pattern is controlled by overlapping proximal and distal somatic gonad signals.
The establishment of Caenorhabditis elegans germline pattern is controlled by overlapping proximal and distal somatic gonad signals.
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DOI：
10.1016/s0012-1606(03)00203-3
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发表时间：
2003-07
影响因子：
2.7
通讯作者：
A. Pepper;Te-Wen Lo;D. Killian;D. Hall;E. Hubbard
中科院分区：
文献类型：
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作者：
A. Pepper;Te-Wen Lo;D. Killian;D. Hall;E. Hubbard
我们通过分析 glp-1 和 lag-2 突变体、细胞消融和超微结构数据，研究了幼虫秀丽隐杆线虫雌雄同体种系的增殖和分化控制。在前几轮生殖细胞分裂后，GLP-1（LIN-12/Notch 家族的受体）控制生殖系增殖。我们分析了 glp-1(ar202) 的近端增殖 (Pro) 表型，发现初始减数分裂延迟且空间错位。这至少部分是由于突变型 GLP-1 受体对多种来源的体细胞配体 LAG-2（包括近端体细胞性腺）的反应增强。我们研究了近端 LAG-2 是否影响野生型的种系增殖。我们的结果表明，(1) LAG-2 对于 GLP-1 介导的种系增殖和预防早期减数分裂是必需的，(2) 幼虫体细胞性腺中 LAG-2 的几个不同的解剖来源在功能上重叠，以促进增殖和预防早期减数分裂。超微结构研究表明，有丝分裂并不局限于 DTC 与种系直接接触的区域，并且种系在幼虫阶段共享共同的细胞质。我们提出减数分裂开始时近端种系中 GLP-1 信号通路的下调受到严格的时间和空间控制。
We investigated the control of proliferation and differentiation in the larval Caenorhabditis elegans hermaphrodite germ line through analysis of glp-1 and lag-2 mutants, cell ablations, and ultrastructural data. After the first several rounds of germ cell division, GLP-1, a receptor of the LIN-12/Notch family, governs germline proliferation. We analyzed the proximal proliferation (Pro) phenotype in glp-1(ar202) and found that initial meiosis was delayed and spatially mispositioned. This is due, at least in part, to a heightened response of the mutant GLP-1 receptor to multiple sources of the somatic ligand LAG-2, including the proximal somatic gonad. We investigated whether proximal LAG-2 affects germline proliferation in the wild type. Our results indicate that (1) LAG-2 is necessary for GLP-1-mediated germline proliferation and prevention of early meiosis, and (2) several distinct anatomical sources of LAG-2 in the larval somatic gonad functionally overlap to promote proliferation and prevent early meiosis. Ultrastructural studies suggest that mitosis is not restricted to areas of direct DTC-germ line contact and that the germ line shares a common cytoplasm in larval stages. We propose that downregulation of the GLP-1 signaling pathway in the proximal germ line at the time of meiotic onset is under tight temporal and spatial control.