The P-element in G-iα65AKG01907 has been excised to generate a mutant deletion, uncovering the first two exons that includes the codon for translation initiation.
mitotic domain 9 & epithelial cell
spindle & external sensory organ precursor cell I
spindle & neuroblast
In G-iα65AP8 mutant pI sensory organ precursor cells, the spindle appears more tilted along the apico-basal axis than normal, although it is correctly oriented along the anterior-posterior axis in these cells.
G-iα65AP8 maternal and zygotic embryos show a mild defect in the formation of the blood-brain barrier, as assessed by the penetration of fluorescent dye.
20% of telophase neuroblasts divide into two similar-sized daughter cells in homozygous embryos derived from homozygous female germline clones.
The number of EL neurons per hemisegment is reduced compared to wild type in homozygous embryos derived from homozygous female germline clones.
G-iα65AP8 mutant epithelial mitotic domain 9 cells divide not only perpendicular to the surface (as occurs in wild type) but also parallel or at an oblique angle to the surface.
G-iα65AP8 flies lacking zygotic G-iα65A are viable, show locomotion defects, but nevertheless lay fertilised eggs. The majority of the embryos derived from these homozygous animals lacking both maternal and zygotic components die as larvae. An RP2sib to RP2 cell fate change is observed in G-iα65AP8 mutants. RP2sib appears to adopt an RP2 cell fate in ~10% of mutant hemisegments. RP2 is absent in ~11% of G-iα65AP8 mutant hemisegments. Mitotic spindle formation is affected in G-iα65AP8 mutants. In mitotic domain 9, mitotic spindles fail to undergo 90o reorientation, and these cells divide parallel to the embryonic surface. Approximately 79% of G-iα65AP8 mutant neuroblasts generate an asymmetric spindle and produce two daughter cells with different cell sizes; the other 21% produce a symmetric spindle, forming equally-sized daughters.
GαiP8 is a non-enhancer of perineurium | embryonic stage phenotype of Pka-C1B3
GαiP8 is a non-suppressor of perineurium | embryonic stage phenotype of Pka-C1B3
Equal size division between neuroblast daughter cells is observed in GαiP8 insc22 mutant cells. In contrast to wild-type neuroblasts, in GαiP8 insc22 mutant neuroblasts, the spindle geometry, remains symmetric even at telophase with the cleavage plane being equidistant to both centrosomes. The spindle is positioned symmetrically with both centrosomes lying in close proximity to the cell cortex. In GαiP8 insc22 double mutant neuroblasts, both centrosomes are associated with astral microtubules, with a cap structure forming over each centrosome from metaphase onwards. This phenotype is not observed in single mutants for these genes.
