Oogenesis appears completely normal in tra¹/Df(3L)st-j7 chromosomal females carrying tra^F.Hsp83, although most of these females can not lay eggs. tra^F.Hsp83 feminises the soma of XY animals, and the external morphology of these flies is essentially indistinguishable from that of wild-type females. Complete somatic transformation is seen with a single copy of tra^F.Hsp83 even at 18^oC. The XY pseudofemales lack sex combs and have female genitalia and pigmentation, but are sterile. However, the body size of these XY animals is unaffected by tra^F.Hsp83; they are similar in size to wild-type males. The somatic tissues in the gonads of the XY pseudofemales are feminised and are subdivided into a series of ovariole-like structures. However, these ovarioles are typically abnormal. Within each ovariole, the somatic follicle cells surround and pinch off a series of pseudo-egg chambers that are filled with a multitude of small, largely undifferentiated germ cells. When transgenic lines containing tra^F.Hsp83 were first recovered, XY pseudofemales with ovaries in which one or more of the ovarioles had egg chambers that closely resembled the previtellogenic chambers of normal XX females were seen. The developing egg chambers in these ovarioles contain nurse cells with polyploid nuclei and a cell at the posterior that may correspond to the oocyte. Mature but misshapen eggs were also seen but they were never laid. These "normal" ovarioles were seen only infrequently (2-5%). The penetrance of this phenotype decreased since the lines were first isolated and is no longer observed. Transgenic lines containing tra^F.Hsp83 can be obtained from male embryos injected with the construct. One G_o male was found in which approximately 70% of the progeny were transformants. The high frequency of transformants suggests that a substantial proportion of germline stem cells in this animal had an integrated copy of the P{Hsp83-tra.F} transgene. This indicates that tra protein expression within XY germ cells is not in itself sufficient to initiate female differentiation.

XY animals carrying tra^F.Hsp83 are feminised, although some male-specific structures, such as the muscle of Lawrence are still present. When these pseudofemales are placed in individual chambers with another male or female they show little interest in courting. When they do court they do not discriminate between males and females and only very early courtship routines, such as orientation, tapping and brief wing vibration are seen. These pseudofemales elicit high levels of courtship from wild-type males and allow themselves to be mated. The pheromone profile of XY flies carrying tra^F.Hsp83 resembles that of wild-type females.

tra^F.Hsp83 is a suppressor of abnormal sex-determination | female phenotype of Sxl^M1,f3/Sxl^f7,M1

tra^F.Hsp83 is a suppressor of abnormal sex-determination | recessive | female phenotype of Sxl^M1,f3

tra^F.Hsp83 is a suppressor of abnormal sex-determination | recessive | female phenotype of Sxl^f7,M1

tra^F.Hsp83 is a suppressor | partially of gonad phenotype of Sxl^M1,f3/Sxl^f7,M1

tra^F.Hsp83 is a suppressor of gonad phenotype of Sxl^f7,M1