Preliminary evidence of genetic control of sex chromosomal synapsis in the mouse.

Highly inbred strains of mice have contrasting means and low ranges for the trait of gonosomal univalency at diakinesis-metaphase I. Randomly bred and mixed strains have wider ranges. The inbred strain DBA/2J has a high mean, and this character is evidently transmitted through the male parent. This material may provide a valuable model for study of genetic control of XY pairing.