Src64 is involved in fusome development and karyosome formation during Drosophila oogenesis.
Src family tyrosine kinases respond to a variety of signals by regulating the organization of the actin cytoskeleton. Here, we show that during early oogenesis Src64 mutations lead to uneven accumulation of cortical actin, defects in fusome formation, mislocalization of septins, defective transport of Orb protein into the oocyte, and possible defects in cell division. Similar mutant phenotypes suggest that Src64, the Tec29 tyrosine kinase, and the actin crosslinking protein Kelch act together to regulate actin crosslinking, much as they do later during ring canal growth. Condensation of the oocyte chromatin into a compact karyosome is also defective in Src64, Tec29, and kelch mutants and in mutants for spire and chickadee (profilin), genes that regulate actin polymerization. These data, along with changes in G-actin accumulation in the oocyte nucleus, suggest that Src64 is involved in a nuclear actin function during karyosome condensation. Our results indicate that Src64 regulates actin dynamics at multiple stages of oogenesis.
Department of Molecular and Cell Biology, 16 Barker Hall, University of California, Berkeley, CA 94720, USA.
Inna
I
Djagaeva
Sergey
S
Doronkin
Steven K
SK
Beckendorf
D000199:Actins / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D002467:Cell Nucleus / Q000502:physiology*; D042002:Chromatin Assembly and Disassembly / Q000502:physiology; D003433:Crosses, Genetic; D003599:Cytoskeleton / Q000378:metabolism / Q000502:physiology*; D004330:Drosophila; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D005260:Female; D007150:Immunohistochemistry; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D009866:Oogenesis / Q000502:physiology*; D021381:Protein Transport / Q000502:physiology; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000502:physiology
D000199:Actins; D029721:Drosophila Proteins; D008840:Microfilament Proteins; D011518:Proto-Oncogene Proteins; D016601:RNA-Binding Proteins; C080353:kel protein, Drosophila; C089932:orb protein, Drosophila; C113193:Tec29 protein-tyrosine kinase; D011505:Protein-Tyrosine Kinases; C075699:Src64B protein, Drosophila