Time Required for Drosophila Males to Exhaust the Supply of Mature Sperm

Abstract

Males of the wild-type Swedish-b stock of D. melanogaster were treated with 3000 r. of X-radiation and repeatedly mated on the day of treatment, on the 6th day, the 7th day, the 12th day and the 19th day thereafter. A drop in the % of dominant lethals was not observed until the 19th day, indicating that the sperm which was immature at the time of treatment does not become available until some time after 12 days. In-dividual [male][male] apparently vary considerably. The less affected sperm seems to become available between 15 and 19 days after treatment, provided the sperm which was mature at the time of treatment has previously been used. When [male][male] copulated for the first time on the 19th day after the treat-men 2 copulations did not exhaust the old sperm. The fully matured sperm available for immediate transfer may become exhausted in a few consecutive matings.