Hop-sterile, a mutant gene affecting sperm tail development in the mouse

Abstract
Hop-sterile (hop) is a new mutation in the mouse, the effects of which include complete male sterility, a ‘hopping’ gait and preaxial polydactyly of all feet. Ultrastructural studies of spermiogenesis show that sperm tails are absent or highly modified. Second meiotic division is frequently abnormal or incomplete, often with four centrioles per cell. These centrioles usually fail to form fiagella and sperm tail development is arrested.