Bicaudal-D is essential for egg chamber formation and cytoskeletal organization in drosophila oogenesis.
Bicaudal-D (Bic-D) is required for the transport of determinant mRNAs and proteins to the presumptive oocyte, an essential step in the differentiation of the oocyte. Bic-D protein contains four well-defined heptad repeat domains characteristic of intermediate filament proteins. We characterized the ovarian phenotypes of females expressing mutant Bic-D proteins (Bic-D(H)) deleted for each of the heptad repeat domains. The altered migration of follicle cells we observe in mutant ovaries suggests that Bic-D functions in the germline and directs the inward migration of somatic follicle cells. In the germarium Bic-D is required for the organization of the egg chamber and the structural integrity of the oocyte and nurse cells. Examination of the polarized microtubule network in Bic-D(H) ovaries shows that Bic-D function is required for both the establishment of the polarized microtubule network and its maintenance throughout oogenesis. To explain the multiple functions suggested by the pleiotropic Bic-D phenotype, we propose that Bic-D protein could form itself a filamentous structure and represent an integral, essential part of the cytoskeleton.
Waksman Institute, Department of Molecular Biology and Biochemistry, Rutgers University, 190 Frelinghuysen Road, Piscataway, New Jersey, 08854, USA.
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D000818:Animals; D002454:Cell Differentiation; D002465:Cell Movement; D016764:Cell Polarity; D003599:Cytoskeleton / Q000737:chemistry*; D004330:Drosophila; D029721:Drosophila Proteins; D005260:Female; D019476:Insect Proteins / Q000032:analysis / Q000502:physiology*; D009154:Mutation; D009865:Oocytes / Q000502:physiology; D009866:Oogenesis
C061998:BicD protein, Drosophila; D029721:Drosophila Proteins; D019476:Insect Proteins; C104613:egl protein, Drosophila