The testes of homozygous males are of normal size and shape, but there are no mature sperm in the seminal vesicle. All stages of spermatogenesis up through spermatid elongation appear normal in the mutant males, however, there are defects in sperm individualisation, resulting in few, if any, mature motile sperm.

Defects in nuclear morphological changes are seen during spermatid bundle elongation in mutant males; some nuclei do not fully condense, some are scattered and some lose the rigid needle-like shape and appear curled, and in many cases contorted into circles. The defects become more severe in older males, with an increase in scattered nuclei.

The initial assembly of the actin cones of the individualization complex and their triangular shape is normal in mutant males. However, the coordinated movement of these cones is disrupted in the mutant males, with the disruption becoming more extreme as the cones move further down the spermatid bundles.

Prosα6T¹ has male sterile | recessive phenotype, suppressible by Prosα6^Prosα3T.PZ