60 Oral - Cell Division and Cell Growth
Friday April 08, 8:30 AM - 8:45 AM

Authors:
Lelahiwat Legesse; Blake Riggs

Affiliation: San Francisco state university

Keywords:
c. organelle maintenance & replication; b. cell polarity

In the central nervous system (CNS), cell diversity is accomplished by asymmetric cell division, a
fundamental and highly conserved process during development of multicellular life. Drosophila
melanogaster neural progenitor cells, or neuroblasts (NB), are one of the best models for
studying asymmetric division. Neuroblast undergoes asymmetric division generating one selfrenewing
daughter neuroblast and another cell known as a ganglion mother cell (GMC). An
essential factor for asymmetric division is the correct establishment of cellular polarity which is
required for the correct partitioning of cell fate determinants. However, it is unclear the pathway
by which these determinants are distributed and arranged during asymmetric divisions. Apicalbasal
polarity is established through an evolutionarily conserved protein complex that includes
Bazooka (Baz), Par-6, aPKC. Previous research has determined that the endoplasmic reticulum
(ER) divides asymmetrically during mitosis prior to neuroblast differentiation with the
requirement of a novel ER protein Jagunal (Jagn). Here we propose to investigate if ER
asymmetry during mitosis plays a role in cortical polarity. Through genetic cross and
immunohistochemistry, I determined that in the larval neuroblast, ER does not co-localize with
apical or basal cell fate determinates, Bazooka (Baz) or Prospero (Pros), respectively. Future
studies will include embryo fixations to investigate if there could be a possible colocalization
earlier in development as well examining if Baz is necessary for ER asymmetric partitioning
during cell division. These approaches will help define the role of Jagn in asymmetric ER
division and neuroblast development.