Imprecise excision of P{lacW}Hrb87FY1217 resulting in a deletion which removes the Hrb87F coding region and extends into the neighbouring Rbp4 gene. Part of the original insertion remains.
Homozygous Df(3R)Hrb87F males are completely sterile.
Hrb87F null animals (Df(3R)Hrb87F homozygotes in which Rbp4[+] function has been rescued by two copies of Rbp4tHa) exhibit delayed pupation. The time gap between first and last pupation is significantly greater in Hrb87F null animals than in wild-type and increases with lower rearing temperature. The duration of each larval instar is extended compared to wild type in the Hrb87F null animals. Hrb87F null pupae show a comparable delay in the emergence of adults.
Approximately 57% of Hrb87F null larvae pupate on the surface of food (in contrast to wild type, where only 3% of wild-type larvae pupate on food, with the rest pupating on drier surfaces away from the food).
No significant larval or pupal lethality is found in Hrb87F null animals that are reared at 24[o]C or at 18[o]C. However, Hrb87F null flies grown at 24[o]C appear a little weak and lethargic compared to the wild-type, and with age, their weakness increases substantially. The median life span of Hrb87F null flies at 24[o]C is significantly less than that of wild-type controls.
Nearly 70% of 30[o]C reared Hrb87F null animals die as late pupae or pharates or soon after emergence. The surviving flies are very weak, unable to fly, lay very few eggs and die within a few days.
In contrast to wild type, one of the two ovaries in Hrb87F null females is often much smaller than the other. The total number of ovarioles in the Hrb87F null females is significantly less in wild-type at both 3 or 10 days of age. Between 3 to 9 days of adult life, Hrb87F null females lay fewer eggs than correspondingly-aged wild-type females.
Hrb87F null females exhibit defects in the organization of F-actin in the thin circular muscles of the epithelial sheath surrounding each of the ovarioles. Unlike the thin and rather discontinuous actin filaments in the epithelial sheath covering the wild-type ovarioles, continuous and a higher number of actin filaments wrap the entire ovariole in Hrb87F null ovaries. Ring canals appear normal in the mutant egg chambers. The F-actin layer at the interface of follicle and nurse cells in Hrb87F null chambers is thinner than in wild-type chambers. Further, many of the Hrb87F null ovarioles do not contain egg chambers beyond stage 7-8, possibly due to a high incidence of apoptosis in Hrb87F null flies. Hrb87F null ovarioles are also affected. The highly endoreplicated chromatin in nurse cell nuclei remains more condensed in blob-like structures even in later stages.
The Malpighian tubules of Hrb87F null larvae are nearly two times thicker than in the wild-type. Correspondingly, the nuclei in the polytenized principal cells of Malpighian tubules of Hrb87F null larvae are also nearly two times larger than in wild-type controls.
Starvation of Hrb87F null flies results in death as early as within 24 hours. After 50 hours of starvation approximately 90% of Hrb87F null flies are dead, while in the case of control flies, a comparable percentage of death is observed after 90 hours of starvation.
Hrb87F null flies display increased thermo-sensitivity. After a 1 hour exposure to 37[o]C, only 65% of the larvae survive to adulthood (compared to 97% emergence of similarly treated wild-type larvae). Likewise, only 25% of Hrb87F null larvae exposed to 37[o]C for 2 hours emerge as flies (in contrast to 88% emergence of wild-type larvae). Five days after heat shock, only 53% of Hrb87F null flies survive, compared to 95% of wild-type flies.
Df(3R)Hrb87F homozygotes are viable without any apparent phenotype. However the eyes show slight roughening and pseudopupil analysis reveals a loss of photoreceptor neurons.
Df(3R)Hrb87F heterozygotes do no show any detectable abnormalities in eyes.
Deletion of the entire Hrb87F coding region and a portion of the adjacent 3' gene.