Coordination of cell cycle and morphogenesis during organ formation

Abstract

AbstractOrgan formation requires precise regulation of cell cycle and morphogenetic events. Using theDrosophilaembryonic salivary gland (SG) as a model, we uncover the role of the SP1/KLF transcription factor Huckebein (Hkb) in coordinating cell cycle regulation and morphogenesis. Thehkbmutant SG exhibits defects in invagination positioning and organ size due to abnormal death of SG cells. Normal SG development involves distal-to-proximal progression of endoreplication (endocycle), whereashkbmutant SG cells undergo abnormal cell division, leading to cell death. Hkb represses the expression of key cell cycle and pro-apoptotic genes in the SG. Knockdown ofcyclin Eorcyclin-dependent kinase 1,or overexpression offizzy-relatedrescues most of the morphogenetic defects observed in thehkbmutant SG. These results indicate that Hkb plays a critical role in controlling endoreplication by regulating the transcription of key cell cycle effectors to ensure proper organ formation.