Radiosensitivity at Specific Autosomal Loci in Mature Sperm and Spermatogonial Cells of Drosophila Melanogaster.

HE characteristics of mutational damage recovered from spermatogonial cells Tare important for considerations of genetic risks from radiation. The genetic and cytological types of mutations recovered from spermatogonia determine the chances of genetic damage offered the ensuing populations. To study these characteristics, radiation studies were carried out in Drosophila where well defined genetic and cytological tests are available. The previous study showed a higher mutation rate for mature sperm than for spermatogonia (ALEXANDER 1954). Different total doses were used, and tests for mature sperm given 900r of X-rays were not available to clarify whether sperm rates were significantly higher when calculated from only nonbreakage types. Additional data were obtained for spermatogonial cells treated with 900r, and genetic and cytological data were obtained for mature sperm treated with 900r. Direct comparisons of genetic damage in the two types of cells are made.