Amino acid replacement: A278T.
Carries a single non-synonymous nucleotide change leading to an Ala278->Thr amino acid substitution in mt:Cyt-b.
Testes from mt:Cyt-bBrownsville mutant males fail to individualise spermatids due to failure of formation of individualisation complex. Clusters of spermatid nuclei scatter through testes and eventually degrade in basal region of testis. The sterile mt:Cyt-bBrownsville mutant males are otherwise healthy and active, although their mean lifespan is lower that that of a wild-type strain, largely due to excess deaths on days 10-13.
