Multiple Functions of the Essential Gene in Early Development.

() encodes the homolog of the evolutionarily conserved Protein Phosphatase 6 (PP6). The physiological and developmental functions of PpV/PP6 have not been well characterized due to lack of a genetically defined mutant. Here, we identified a non-sense mutation and describe multiple mutant phenotypes in oogenesis and early embryogenesis. Specifically, we found that the defects in chromosome segregation during nuclear cycles are related to AuroraA function, which is consistent with the interaction of PP6 and AuroraA in mammalian cells. Surprisingly, we also identified a function specifically in blastoderm cell cycle but not in cell proliferation in the follicle epithelium or larval wing imaginal discs. Embryos from germline clones frequently undergo an extra nuclear division cycle. By epistasis analysis, we found that functions in parallel with , but independently of for the remodeling of the nuclear cycles. Taken together, this study reports novel developmental functions of and provides a framework for further genetic analysis under physiological conditions.