Joyner A L, Herrup K, Auerbach B A, Davis C A, Rossant J
Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada.
Science. 1991 Mar 8;251(4998):1239-43. doi: 10.1126/science.1672471.
The two mouse genes, En-1 and En-2, that are homologs of the Drosophila segmentation gene engrailed, show overlapping spatially restricted patterns of expression in the neural tube during embryogenesis, suggestive of a role in regional specification. Mice homozygous for a targeted mutation that deletes the homeobox were viable and showed no obvious defects in embryonic development. This may be due to functional redundancy of En-2 and the related En-1 gene product during embryogenesis. Consistent with this hypothesis, the mutant mice showed abnormal foliation in the adult cerebellum, where En-2, and not En-1, is normally expressed.
两个与果蝇分节基因engrailed同源的小鼠基因En-1和En-2，在胚胎发生过程中神经管内呈现出空间限制的重叠表达模式，提示其在区域特化中发挥作用。缺失同源框的靶向突变纯合小鼠是存活的，并且在胚胎发育过程中未表现出明显缺陷。这可能是由于胚胎发生过程中En-2与相关的En-1基因产物存在功能冗余。与该假设一致，突变小鼠成年小脑出现叶状异常，正常情况下En-2而非En-1在小脑中表达。
