A novel calcyphosine-like protein facilitates border cell migration during oogenesis. Lathiena A. Manning, Michelle Starz-Gaiano. Biological Sciences, University of Maryland Baltimore County, Baltimore, MD.

   Collective cell migration is crucial to an organisms capacity to perform morphogenesis thereby creating body plans and organ systems. Cells that move as clusters must maintain their primary adhesions to their migratory counterparts while altering adhesions to stationary cells allowing for detachment and subsequent movement. We are employing the Drosophila melanogaster oocyte development to study cell detachment and migration amongst a small population of specialized cells referred to as border cells . Border cells differentiate and detach from the anterior epithelium and migrate posteriorly toward the oocyte while remaining in a cluster. Border cells display the characteristics of collective cell migration as they move. Both the single Drosophila steroid hormone, Ecdysone and JAK/STAT signaling pathways are essential in the expression of specific genes needed for coordinating border cell migration. Our work focuses on an uncharacterized calcyphosine-like protein (CAPSL) that potentially acts downstream of both signaling pathways. This calcyphosine-like protein contains EF hand domains, which are known for binding calcium. Though this protein is present in several tissue types, the specific function remains a mystery. We set out to determine the specific role that CAPSL plays in border cell migration. Gene expression analysis demonstrated the presence of the CAPSL in border cells prior to detachment and during early migration. Various alleles that reduce expression of the gene in the border cells disrupted their proper migration. We are testing the hypothesis that the calcyphosine-like protein disrupts actin dynamics preventing the cellular rearrangements needed for migration.