[A partially inheritable aging influence on a non-Mendelian female sterility in Drosophila melanogaster].

Some crosses between strains of Drosophila melanogaster give rise to F1 females, which display a quite characteristic kind of incomplete sterility (S.F. females). The sterility appears to result from the interaction between two factors, "I" brought by the male parent, "R" by the female parent, neither of which behave like classical mendelian genes. In this paper, results are presented which demonstrate that the level of sterility of an S.F. female depends on the age of its maternal ancestors. Therefore, aging of a reproducing female induces variations in the "R" factor which are inherited and behave like "dauermodifikation".