Studies on the Karyotype Differentiation of the Norway Rat. IX

Translocation between Pair Nos. 4 and 7 occurred in a WM Strain Rat after γ-Irradiation, with Special Regard to the Segregation in F₁ Hybrids involving an XYY Male

Abstract

A male WM strain rat with 4/7 translocation was obtained in the offspring born after γ-irradiation. The male with translocation was mated to the normal females, and 14 offspring was obtained. They were segregated to the translocation heterozygotes (7) and the non-translocation rats (7) as just expected. Among the latter rats, one had the XYY sex chromosomes which were suggested to be developed by non-disjunction of the Y element in the meiosis of the translocation male parent.