Jiang Z, Zacksenhaus E, Gallie B L, Phillips R A
Department of Molecular and Medical Genetics, University of Toronto, The Hospital for Sick Children, Ontario, Canada.
Oncogene. 1997 Apr 17;14(15):1789-97. doi: 10.1038/sj.onc.1201014.
We report differential expression of the RB1 tumor suppressor gene and the homologous genes p107 and p130 during embryogenesis. Abundant RB1 transcripts were detected during neurogenesis, hematopoiesis, myogenesis, lens development and in the ganglion cell layer of the embryonic retina, prior to and during differentiation. The expression pattern of RB1 mirrored the defects in RB1 mutant mice (RB-/-). In the heart, lung, kidney and intestine, p107, but not RB1, was expressed. In the liver and the central nervous system p107 and RB1 were co-expressed, consistent with the accelerated cell death observed in RB-/-; p107-/- double knock-out mice. In the central nervous system, p107 expression was restricted to proliferating cells surrounding the ventricles, while RB1 was expressed in areas of both proliferating and differentiating cells. In contrast to RB1 and p107, expression of p130 was low throughout embryogenesis. In situ hybridization and Western blot analyses showed that the expression of p107 and p130 was not markedly altered in RB-/- embryos compared to control littermates. Our results suggest that members of RB1 gene family have distinct, but overlapping roles in embryogenesis, with p107 and RB1 possibly having redundant functions in the central nervous system and liver.
我们报告了RB1肿瘤抑制基因以及同源基因p107和p130在胚胎发生过程中的差异表达。在神经发生、造血、肌发生、晶状体发育过程中以及胚胎视网膜神经节细胞层分化之前和期间，检测到大量RB1转录本。RB1的表达模式反映了RB1突变小鼠（RB-/-）中的缺陷。在心脏、肺、肾和肠道中，表达的是p107，而非RB1。在肝脏和中枢神经系统中，p107和RB1共同表达，这与在RB-/-；p107-/-双敲除小鼠中观察到的细胞死亡加速一致。在中枢神经系统中，p107的表达局限于脑室周围的增殖细胞，而RB1在增殖细胞和分化细胞区域均有表达。与RB1和p107不同，p130在整个胚胎发生过程中的表达水平较低。原位杂交和蛋白质印迹分析表明，与对照同窝仔相比，RB-/-胚胎中p107和p130的表达没有明显改变。我们的结果表明，RB1基因家族成员在胚胎发生中具有不同但重叠的作用，p107和RB1可能在中枢神经系统和肝脏中具有冗余功能。
