Imprecise excision of P{lacW}rin1 resulting in a 3.3 kb deletion of most of the rin coding region.
egg | maternal effect (with rin2)
Although rin3 flies are homozygous and hemizygous viable, homozygous and hemizygous rin3 flies show a 40% reduction in viability compared with their heterozygous siblings.
Homozygous rin3 mutants have noticeably shorter lifespan than their heterozygous siblings. Homozygous rin3 flies begin to die starting three or four days after hatching from pupae. After the second and third weeks approximately 35% and 70% of the adult flies are dead, respectively.
Both homozygous rin3 and hemizygous rin3/Df(3R)urd and rin3/Df(3R)l26c females are completely sterile.
rin3 mutants have a spectrum of oogenesis defects. One of the earliest defects is the improper encapsulation of germline-derived cells by follicular epithelium. rin3 mutant ovarioles often have adjacent egg chambers with too few nurse cells. A second defect that becomes evident at or before the beginning of vitellogenesis is the abnormal packaging of chromatin in nurse cell nuclei.
rin3 mutant egg chambers show defects in the organisation of the nurse cell actin cytoskeleton. Actin distribution in nurse cells is abnormal and actin filaments fail to form in stage 10-11 rin3 nurse cells. There are often large actin-free gaps in rin3 egg chambers, and subcortical actin is discontinuous. Perhaps the most striking defects are in the ring canals. There are a variety of ring canal defects in rin3 mutant egg chambers that become more prevalent in later stages of oogenesis. In addition to fragmented or incomplete, ring canals, ring canals that are much larger than normal are also observed. As multinucleated nurse cells are often seen in rin3 mutant egg chambers, it is possible that the nurse cells may fuse following ring canal failure. One of the terminal phenotypes is dumpless.
About 10% of eggs produced by rin3/rin2 mothers are ventralised. While the remainder of the eggs show seemingly normal eggshells, cuticle preparations of the embryos produced by rin3/rin2 mothers reveal severe defects in embryonic development. For example, many of the embryos are underdeveloped or have only scraps of cuticle.
rin3/rin[+] is an enhancer of egg chorion | temperature conditional phenotype of Ecol\lacZHsp83.orb.8E2Hd, orbF343
The frequency of ventralised eggs is increased three-fold or more depending on the temperature when orb8E2Hd.Hsp83.T:Ecol\lacZ rin3 orbF343/+ mothers are also heterozygous for rin3.
