Labouesse M, Hartwieg E, Horvitz H R
Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge 02139, USA.
Development. 1996 Sep;122(9):2579-88. doi: 10.1242/dev.122.9.2579.
The C. elegans gene lin-26, which encodes a presumptive zinc-finger transcription factor, is required for hypodermal cells to acquire their proper fates. Here we show that lin-26 is expressed not only in all hypodermal cells but also in all glial-like cells. During asymmetric cell divisions that generate a neuronal cell and a non-neuronal cell, LIN-26 protein is symmetrically segregated and then lost from the neuronal cell. Expression in glial-like cells (socket and sheath cells) is biologically important, as some of these neuronal support cells die or seem sometimes to be transformed to neuron-like cells in embryos homozygous for strong loss-of-function mutations. In addition, most of these glial-like cells are structurally and functionally defective in animals carrying the weak loss-of-function mutation lin-26(n156). lin-26 mutant phenotypes and expression patterns together suggest that lin-26 is required to specify and/or maintain the fates not only of hypodermal cells but also of all other non-neuronal ectodermal cells in C. elegans. We speculate that lin-26 acts by repressing the expression of neuronal-specific genes in non-neuronal cells.
秀丽隐杆线虫基因lin-26编码一种假定的锌指转录因子，是皮下细胞获得其正常命运所必需的。我们在此表明，lin-26不仅在所有皮下细胞中表达，也在所有神经胶质样细胞中表达。在产生一个神经元细胞和一个非神经元细胞的不对称细胞分裂过程中，LIN-26蛋白被对称分离，然后从神经元细胞中消失。在神经胶质样细胞（套细胞和鞘细胞）中的表达具有生物学重要性，因为在功能严重丧失的纯合突变胚胎中，这些神经元支持细胞中的一些会死亡，或者有时似乎会转变为神经元样细胞。此外，在携带功能丧失性弱突变lin-26(n156)的动物中，这些神经胶质样细胞中的大多数在结构和功能上存在缺陷。lin-26突变体表型和表达模式共同表明，lin-26不仅是确定和/或维持秀丽隐杆线虫皮下细胞的命运所必需的，也是所有其他非神经元外胚层细胞的命运所必需的。我们推测，lin-26通过抑制非神经元细胞中神经元特异性基因的表达来发挥作用。
