Biological Damage in Mature and Immature Germ Cells of Drosophila Virilis with Ionizing Radiations.

IOLOGICAL damage resulting from radiation treatment has been studied in a B number of biological systems (LEA 1947; HOLLAENDER 1954; BARQ and ALEXANDER 1955). ZIRKLE (1954) discussed the implications of the observed influence of linear energy transfer upon biological damage. More recently BURCH ( 195 7) has discussed several problems of relative biological efficiency with respect to the methods used tQ characterize the quality of ionizing radiations. In Drmaphila, differences in the number of sex-linked recessive lethals recovered after X-radiation treatment of mature and immature germ cells were reported earlier by HARRIS (1929), HANSEN and HEYS (1929) and DEMEREC and KAUFMANN (194.1 ) . LUNNING (1952) reported differences in the effectiveness of X-radiation for dominant lethal damage in the spermatogenic cycle of Drosophila melanogaster. The characteristics of biological damage in various types of germ cells of DrosapGla uirdis subjected to fission neutrons and 14 Mev neutrons and comparisons a f the results obtained with neutrons to those producqd by ionizing radiations have been discussed in previous papers (ALEXANDER 1958a,