PgmNr D205: Asymmetric Endoplasmic Reticulum partitioning is dependent on Jagunal in the early Drosophila embryo.

Authors:
B. Riggs; A. Eritano; A. Altamirano; S. Beyeler


Institutes
San Francisco State University, San Francisco, CA.


Keyword: mitosis

Abstract:

Cell division is classically described as the division of genetic material and the corresponding reorganization of the cytoskeleton. However, the mechanisms by which organelles are segregated into daughter cells remain poorly understood. In investigating the molecular mechanisms underlying partitioning of the Endoplasmic Reticulum (ER), we sought to quantify ER segregation during cell division in the early gastrulating Drosophila embryo. Interestingly, we found, that at the start of gastrulation (14th mitotic division), the ER divides asymmetrically in a population of asynchronously dividing epithelial cells at the anterior end of the embryo. Asymmetric division of the ER is restricted to this anterior population of cells, as other cellular domains during the 14th mitosis display a symmetrical division. Furthermore, we found this asymmetric division of the ER dependent on the highly conserved membrane protein Jagunal. RNA inhibition of Jagunal, just prior to the start of gastrulation, disrupts this asymmetric division of the ER. This anterior cell population will eventually give rise to the asymmetrically dividing procephalic neuroectoderm, suggesting a link between ER distribution and the establishment of cell fate.



Flybase Genetic Index:
1. FlyBase gene symbol: Jagn; FBgn: FBgn0037374