Temperature induced DNA damage is associated with increased transposon mobility in spermatocyte nuclei

Sexually-reproducing organisms use meiosis to generate haploid gametes, such as sperm and eggs, to transmit their genome to the next generation. All tissues are susceptible to dramatic increases in temperature; however, developing sperm in the testes are unusually sensitive to small temperature fluctuations. Failure to thermoregulate spermatogenetic tissue and prolonged exposure to elevated temperatures are linked to male infertility. Further, temperature increases are known to cause DNA damage in spermatocytes, but the molecular mechanisms underlying this damage are unclear. Here we show that upon a brief heat-shock, the spermatocytes (but not oocytes) of Caenorhabditis elegans exhibit an increase in double strand DNA breaks (DSBs), that these temperature-induced DSBs occur via a SPO-11 independent pathway, and occur concurrent with impaired male fertility and temperature-induced transposon activity within the genome.