Germ cell connectivity enhances cell death in response to DNA damage in Drosophila testis

Two broadly known characteristics of germ cells in many organisms are their development as a cyst of interconnected cells and their high sensitivity to DNA damage. Here we provide evidence that these characteristics are linked, and that interconnectivity is a mechanism that confers to the Drosophila testis a high sensitivity to DNA damage. We show that all germ cells within a cyst die simultaneously even when only a subset of them exhibit detectable DNA damage. Compromising connectivity results in cysts in which only a subset of germ cells die upon DNA damage, lowering overall germ cell death. Our data indicate that a death-promoting signal is shared through the intercellular connections of germ cells. Taken together, we propose that intercellular connectivity is a mechanism that uniquely increases the sensitivity of the germline to DNA damage, thereby protecting the integrity of gamete genomes that are passed on to the next generation.