Life and death in the living embryo: live imaging of germ cell migration and programmed cell death in Drosophila melanogaster (694.7)

Abstract

Primordial germ cells (PGCs) in Drosophila melanogaster undergo a choreographed process of migration and programmed cell death during embryogenesis. PGCs generate the future gametes and thus are critical for the continuation of the species. PCGs are the first cells generated in the embryo, and remain sequestered from the somatic cells until after gastrulation. They then migrate through the external epithelial layer into the mesoderm, and diverge as they migrate away from the midgut. Finally, PGCs coalesce with somatic gonadal precursor cells, forming the gonads. Programmed cell death is a crucial part of this process, preventing the persistence of ectopic germ cells. Though a few of the signaling molecules that regulate PGC migration and programmed cell death are known, the molecular mechanisms are not well understood. The scattershot (sctt) mutation of the receptor tre1 leads to disrupted germ cell migration, and appears to have a role in germ cell death as germ cells survive outside of the gonads. Since PGC migration is dynamic and occurs quickly, we use live imaging to observe migration and germ cell death in real time. Using membrane‐localized fluorophores expressed under a germ‐cell‐specific promoter, we will track the migration and death of wild type and tre1sctt germ cells, to further understand how the tre1‐sctt mutation leads to the failure of proper gonad formation and the persistence of ectopic germ cells.