Ends-out homologous recombination has resulted in the ste24a, ste24b and ste24c sequences being replaced by a w^GMR.PH marker. The deletion begins just downstream of the ste24a start site and ends just prior to the termination site in ste24c.

Df(2R)3KO/Df(2R)Exel6065 mutant males exhibit fertility defects.

A third of homozygous Df(2R)3KO mutant males flies are completely sterile while the remainder all produce fewer offspring than controls, and this reduction in fertility is exacerbated with age. Less mature sperm is seen in the testes of Df(2R)3KO mutant males but this reduction is not age-dependent. The early stages of spermatid development appear normal and there is no reduction in pre-meiotic cell types as the males age. Fewer mature individualisation complexes are seen in Df(2R)3KO mutants and this becomes more severe as the flies age; younger age-matched flies show no difference from wild type, whereas older flies show up to a three fold fewer complexes than controls. The scattering of actin cones normally seen in wild type is also reduced in Df(2R)3KO mutants. From approximately 6 days elongated spermatids in Df(2R)3KO mutant males accumulate in the base of the testes, and appear disordered and improperly coiled. Heterozygous Df(2R)3KO mutant males and both homozygous and heterozygous females are viable and fertile.

The lifespan of Df(2R)3KO mutants is reduced in males, but is similar to controls in females. No obvious defects in courtship and mating are seen.