Hui C C, Matsuno K, Ueno K, Suzuki Y
Department of Developmental Biology, National Institute for Basic Biology, Okazaki, Japan.
Proc Natl Acad Sci U S A. 1992 Jan 1;89(1):167-71. doi: 10.1073/pnas.89.1.167.
Genetic analysis in Drosophila has shown that engrailed (en) plays an important role in segmentation and neurogenesis. A closely related gene, invected (in), is coexpressed with en in the posterior developmental compartments where en is known to specify cell state. We report here the isolation of two en-like cDNAs from the middle silk glands of Bombyx mori larvae. Sequence analysis revealed that they are the counterparts of Drosophila en and in. Four highly conserved domains, including the homeodomain, were identified in these En and In proteins from Bombyx and Drosophila. In addition, two en-specific and one in-specific domains could also be found. These structurally homologous genes might share a similar role in Bombyx development. They were found to be coexpressed in the middle silk gland but not in the posterior silk gland during the fourth molt/fifth intermolt period. We speculate that these Bombyx en-like genes might be involved in the compartmentalization of the silk gland.
果蝇的遗传分析表明，engrailed（en）在体节形成和神经发生中起重要作用。一个密切相关的基因，invected（in），与en在后部发育区室中共同表达，已知en在该区域指定细胞状态。我们在此报告从家蚕幼虫中部丝腺中分离出两个en样cDNA。序列分析表明，它们是果蝇en和in的对应物。在家蚕和果蝇的这些En和In蛋白中鉴定出四个高度保守的结构域，包括同源异型结构域。此外，还可以发现两个en特异性结构域和一个in特异性结构域。这些结构同源的基因可能在家蚕发育中发挥相似的作用。发现在第四次蜕皮/第五次龄间期，它们在中部丝腺中共同表达，但在后部丝腺中不表达。我们推测这些家蚕en样基因可能参与丝腺的区域化。
