Zhang P, Knowles B A, Goldstein L S, Hawley R S
Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, New York 10461.
Cell. 1990 Sep 21;62(6):1053-62. doi: 10.1016/0092-8674(90)90383-p.
The nod gene is required for the distributive segregation of nonexchange chromosomes during meiosis in D. melanogaster. Loss-of-function nod mutations cause nondisjunction and loss of nonrecombinant chromosomes both at meiosis I and during subsequent mitotic divisions. We have cloned the nod locus, examined its expression patterns, and determined its coding sequence. In adults the nod transcript is only present in females, consistent with the observation that males do not use the distributive segregation system. However, the nod locus is also transcribed in the embryonic, larval, and pupal stages of development, and possibly in all dividing cells. Finally, the N-terminal domain of the predicted nod protein has amino acid similarity to the mechanochemical domain of kinesin heavy chain; however, the C-terminal domain is unlike that of kinesin heavy chain or of any previously reported protein. Thus, the nod protein is a member of the kinesin superfamily and may be a microtubule motor.
在黑腹果蝇减数分裂过程中，nod基因对于非交换染色体的分布式分离是必需的。功能丧失型nod突变会导致在减数分裂I以及随后的有丝分裂过程中出现非分离现象和非重组染色体的丢失。我们已经克隆了nod基因座，检测了其表达模式，并确定了其编码序列。在成虫中，nod转录本仅存在于雌性个体中，这与雄性不使用分布式分离系统的观察结果一致。然而，nod基因座在胚胎、幼虫和蛹发育阶段也有转录，并且可能在所有分裂细胞中都有转录。最后，预测的nod蛋白的N端结构域与驱动蛋白重链的机械化学结构域具有氨基酸相似性；然而，C端结构域与驱动蛋白重链或任何先前报道的蛋白质不同。因此，nod蛋白是驱动蛋白超家族的成员，可能是一种微管马达。
