S. Mahajanmiklos et L. Cooley, THE VILLIN-LIKE PROTEIN ENCODED BY THE DROSOPHILA QUAIL GENE IS REQUIRED FOR ACTIN BUNDLE ASSEMBLY DURING OOGENESIS, Cell, 78(2), 1994, pp. 291-301
Mutations in the Drosophila quail gene result in female sterility due
to the disruption of cytoplasmic transport from the nurse cells into t
he oocyte late in oogenesis. Nurse cells from quail mutant egg chamber
s fail to assemble cytoplasmic actin filament bundles correctly. We ha
ve cloned the quail gene and found that it encodes a protein with homo
logy to the vertebrate actin-regulating protein villin. Unlike vertebr
ate villin, which is restricted to specialized absorptive epithelial c
ells, the villin-like protein encoded by quail is germline specific in
adult flies. Antibodies directed against the quail protein show a str
iking colocalization with filamentous actin in the nurse cells and the
oocyte. Our results demonstrate that the villin-like product of quail
is required for the formation of cytoplasmic actin filament bundles i
n nurse cells, possibly by regulating both the polymerization and orga
nization of actin filaments as demonstrated for vertebrate villin in v
itro.