Dev Dyn. 2014 Jan;243(1):159-71. doi: 10.1002/dvdy.24064.
Reproduction in animals requires development of distinct neurons in each sex. In C. elegans, most ventral cord neurons (VCNs) are present in both sexes, with the exception of six hermaphrodite-specific neurons (VCs) and nine pairs of male-specific neurons (CAs and CPs) that arise from analogous precursor cells. How are the activities of sexual regulators and mediators of neuronal survival, division, and fate coordinated to generate sex-specificity in VCNs?
To address this, we have developed a toolkit of VCN markers that allows us to examine sex-specific neurogenesis, asymmetric fates of daughters of a neuroblast division, and regional specification on the anteroposterior axis. Here, we describe the roles of the Hox transcription factors LIN-39 and MAB-5 in promoting survival, differentiation, and regionalization of VCNs. We also find that the TALE class homeodomain proteins CEH-20 and UNC-62 contribute to specification of neurotransmitter fate in males. Furthermore, we identify that VCN sex is determined during the L1 larval stage.
These findings, combined with future analyses made possible by the suite of VCN markers described here, will elucidate how Hox-mediated cell fate decisions and sex determination intersect to influence development of neuronal sex differences.
动物的繁殖需要在每个性别中发展出独特的神经元。在秀丽隐杆线虫中，大多数腹索神经元（VCNs）存在于两性中，除了六个雌雄同体特异性神经元（VCs）和九个对雄性特异性神经元（CAs 和 CPs），它们起源于类似的前体细胞。性调节因子和神经元存活、分裂和命运的中介物的活性如何协调，以在 VCN 中产生性别特异性？
为了解决这个问题，我们开发了一套 VCN 标记物工具包，使我们能够检查 VCN 特异性神经发生、神经母细胞分裂后代的不对称命运以及前-后轴上的区域特化。在这里，我们描述了 Hox 转录因子 LIN-39 和 MAB-5 在促进 VCN 存活、分化和区域化中的作用。我们还发现 TALE 类同源域蛋白 CEH-20 和 UNC-62 有助于雄性中神经递质命运的特化。此外，我们确定 VCN 的性别在 L1 幼虫阶段决定。
这些发现，结合这里描述的 VCN 标记物套件未来的分析，将阐明 Hox 介导的细胞命运决定和性别决定如何相互作用，影响神经元性别差异的发育。
