ix1/ix2 mutants do not have surviving doublesex-expressing larval terminal neuroblasts in the terminal region of the female third instar larval ventral nerve cord, similar to controls.
Diplo XX ix1 homozygotes display variable degrees of intersexual characteristics, visible as incomplete and asymmetric development of the external terminalia and internal reproductive organs. The genital arch and anal plates are both affected, bristles are abnormal. Genital disc size is significantly reduced and it's morphology is abnormal. Cell death is elevated in homozygous mutant genital discs. In contrast, no major abnormalities are detected in the terminalia of XY ix1 homozygotes.
Homozygous XX ix1 flies are phenotypically intersexes, with simultaneous realisation of both male and female developmental pathways. The female and male genital primordia develop simultaneously in the genital discs of XX ix1/ix1 larvae.
The pheromone profile of ix1/Df(2R)en-B males is similar to that of wild-type males. The pheromone profile of ix1/Df(2R)en-B females is very different from that of wild-type females.
Diplo-X individuals carrying ix1 display an intersex phenotype. Within the range of intersexual phenotypes in homozygotes or hemizygotes both the male and female type morphological features tend to be more robust at lower temperatures and in hemizygotes. Heterozygotes with ix4 are intersexual at all temperatures, but the extent of intersexuality increases with increasing temperature.
Homozygotes transform XX;AA individuals into intersexes, the morphology of the internal and external genitalia is variable, bristles on the last transverse row of the basitarsus of the foreleg is morphologically intermediate and the genital duct system is duplicated with male and female systems. Homozygous males often have an enlarged sex comb area with the teeth arranged in more than one row. The males are sexually attractive but rarely court with active virgin females.
Female flies lacking ix function have dorsal musculature appropriate to female flies, loss of ix function has no effect on the production of male specific muscle in males.
virts/virts ix1/+ XX flies are females (which are generally fertile) at 25oC.
Homozygous XX flies are intersex.
Females changed into sterile intersexes with a set of reduced male and a set of irregular female external genitalia. Gonads also mixed. They have no sex combs; pigmentation of abdomen intermediate between male and female. A large mass of chitinized tissue protrudes from vaginal opening. Homozygous males look normal but behave like intersexes (McRobert and Tompkins, 1985). They court young males as much as normal males do and occasionally court females; however, they are attractive to normal mature males. Heterozygous ix/+ males court females and young males, but seldom court mature males. The ix locus acts with the dsx female function to allow somatic differentiation in females (Nagoshi, McKeown, Burtis, Belote, and Baker, 1988).