Studies of cell migration and programmed cell death: characterization and analysis of scattershot, a mutation disrupting germ cell migration and programmed cell death in Drosophila melanogaster

Cell migration is a process critical to development, wound healing, immune response and defects in this process are the cause of many disease states. Elucidating the molecular mechanisms and signal transduction cascades mediating this process is crucial to the development of new hypotheses as to the causes, implications, and potential treatments of these diseases. In some cases cell survival/ cell death decisions are closely linked to cell migration in order to rid the organism of cells that are in excess or are located in inappropriate locations and risk harm to the organism. Drosophila germ cell migration provides an excellent system in which to study the interplay of cell migration and cell death decisions. The migratory movements of these germ cells, from their formation at the posterior pole of the embryo to their incorporation into the gonads, have been well characterized and it is known to involve multiple steps. Along this journey, approximately half of the germ cells that originate at the posterior pole are removed from the embryo by programmed cell death. The G protein-coupled receptor, trapped in endoderm 1 (tre1) , is involved in the migration of the germ cells through the posterior midgut epithelium. The scattershot mutation affects both germ cell migration and programmed death of germ cells. We identify the molecular defect in the scattershot mutation that confirms it as an allele of tre1. Additionally, a reverse genetics screen was employed to identify additional genes involved in Drosophila germ cell migration/programmed cell death processes