PgmNr D1086: ER-associated membrane contribution to cellularization furrows in D. melanogaster embryo morphogenesis.

Authors:
E. Holt; B. Riggs


Institutes
San Francisco State University, San Francisco, CA.


Keyword: cytokinesis

Abstract:

Cellular blastoderm formation in the early Drosophila melanogaster embryo occurs as a synchronous compartmentalization of thousands of cortical nuclei during a specialized cytokinetic event known as Cellularization. This process is characterized by the formation of cellularization furrows invaginating between adjacent nuclei. This invagination has been shown to require the reorganization of intracellular membrane stores through endocytic pathways and most recently has been associated with morphological changes to microvillar membrane reservoirs. Currently it is not known if there are additional intracellular components involved in proper furrow formation and as such we are interested in the role of the endoplasmic reticulum and its capacity to act as an intracellular source of membrane. In preliminary investigations we find the ER-associated small GTPase Rab10, known to mark areas of ER-tubule growth, localizes to the ingressing cellularization furrow. We hypothesize that ER-tubule growth constitutes a novel source of membrane contribution during cellularization furrow formation. Here we investigate the role of Rab10 during morphogenesis of the early D. melanogaster embryo. Using time-lapse confocal microscopy we find that cellularization furrow formation kinetics are negatively affected in Rab10-deficient embryos using Rab10.RNAi under GAL4/UAS control. This data suggest a possible role for ER-associated membrane addition during growth phases of furrow ingression. A more detailed functional analysis is necessary to identify the role of ER growth during cellularization.



Flybase Genetic Index:
1. FlyBase gene symbol: Rab10; FBgn: FBgn0015789