Nuclear movement is critical for several developmental processes in eukaryotes. Drosophila oogenesis provides a paradigmatic example in which localization of the nucleus generates a source of cellular asymmetry that is used in patterning both the anterior-posterior and the dorsal-ventral axes of the oocyte. In this study we show that mutations in the Drosophila Lissencephaly1 (DLis1) gene result in partial ventralization of the eggshell. DLis1 mutations affect the localization of gurken mRNA and protein in the oocyte. These defects are correlated with incorrect positioning of the oocyte nucleus, suggesting that DLis1 is required for nuclear migration. DLis1 shows significant sequence conservation across the evolutionary spectrum. Fungal cognates of DLis1 are involved in nuclear migration while homologs in humans and mice are implicated in neuronal migration. DLis1 shows genetic interactions with the Glued and Dynein heavy chain subunits of the dynein/dynactin complex, supporting the idea that the Lis1 family of proteins plays a role in microtubule motor-based nuclear motility.
Copyright 2000 Academic Press.