Cytological Observations Concerning Inversion and Translocation in the House Mouse

Abstract

1. Balanced lethal lines of tailless mice containing a crossover suppressor have been examined cytogenetically. A low frequency of chromatid bridges and fragments in anaphase indicates that if inversion is present it is very small. 2. Pseudo-bridges and lagging chromosomes were found rather frequently in spermatogenesis of both tailless and control animals. 3. Chromosome rings indicating segmental interchanges have been found in spermatogenesis of semi-sterile males, belonging to three different semi-sterile lines.