POSTEMBRYONIC NEUROGENESIS IN THE CNS OF THE TOBACCO HORNWORM, MANDUCA-SEXTA .1. NEUROBLAST ARRAYS AND THE FATE OF THEIR PROGENY DURING METAMORPHOSIS
POSTEMBRYONIC NEUROGENESIS IN THE CNS OF THE TOBACCO HORNWORM, MANDUCA-SEXTA .1. NEUROBLAST ARRAYS AND THE FATE OF THEIR PROGENY DURING METAMORPHOSIS
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DOI：
10.1002/cne.902550407
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发表时间：
1987-01-22
影响因子：
2.5
通讯作者：
TRUMAN, JW
中科院分区：
文献类型：
--
作者：
BOOKER, R;TRUMAN, JW
烟草天蛾从幼虫到成虫的变态过程中，其身体形态和行为发生了巨大的变化。伴随着这些变化的是这种蛾的中枢神经系统（CNS）的广泛重组，这涉及幼虫神经元亚群的死亡和重塑。我们在这里报告说，幼虫的节段神经节也包含一个刻板的阵列的可识别的神经干细胞（神经母细胞），贡献超过2,000个细胞，每个胸神经节和约40-80个细胞，每个腹神经节。这些神经母细胞的分布以节段特异性方式变化。在晚期胚胎和早期一龄幼虫中，发现背侧成神经细胞与神经细胞相邻。蜕皮至二龄后，这些细胞扩大并开始分裂。通过一系列不对称分裂，每个神经母细胞在幼虫生命结束时产生10-90个后代的离散巢。这些后代（成虫巢细胞）在分化的早期阶段发育受阻，并一直保持到变态。在变态开始时，细胞死亡的浪潮席卷整个巢，死亡的程度在腹部巢比胸部巢大得多。存活的成虫巢细胞然后分化成为功能性神经元，并整合到成年CNS中。
The tobacco hornworm Manduca sexta exhibits dramatic changes in its body morphology and behavior as it is transformed from a larva into an adult during metamorphosis. Accompanying these changes is an extensive reorganization of this moth''s central nervous system (CNS), which involves both the death and remodeling of subsets of larval neurons. We report here that the segmental ganglia of the larvae also contain a stereotyped array of identifiable neuronal stem cells (neuroblasts) that contribute over 2,000 cells to each thoracic ganglion and about 40-80 cells to each abdominal ganglion. The distribution of these neuroblasts varies in a segment specific manner. Dormant neuroblasts are found adjacent to the neuropil in late embryos and early first instar larvae. After the molt to the second instar, these cells enlarge and begin to divide. Through a series of asymmetrical divisions, each neuroblast generates a discrete nest of 10-90 progeny by the end of larval life. These progeny (the imaginal nest cells) are developmentally arrested at an early stage of differentiation and remain so until metamorphosis. At the onset of metamorphosis, a wave of cell death sweeps through the nests, the extent of the death being much greater within the abdominal nests than in the thoracic nests. The surviving imaginal nest cells then differentiate to become functional neurons that are incorporated into the adult CNS.