TrlR85/Trlex15 males are unable to produce viable offspring. The testes are 2-4 times smaller than normal and in 90% of cases only early stage (2- and 4-cell) germline cysts are present. Most of the mutant males have empty seminal vesicles, but 5% have a single mature, motile sperm. Mitochondrial defects are seen starting from the spermatogonia stage, with the mitochondria being much larger than normal, having a pale matrix and lacking cristae in many areas. At later stages of spermatogenesis autophagosome formation and massive lysis of the cytoplasm is seen.
Approximately 50% of TrlR85/Trl362 males are fertile, with seminal vesicles containing a small number of motile sperm. The testes are 1.5-3 times smaller than normal. Mitochondria are swollen and poorly condensed in spermatogonia and polar spermatocytes. Spermatocyte degradation is seen.
Defects in primordial germ cell (PGC) migration are seen in TrlR85/Trlex15 embryos. Some of the PGCs fail to migrate, and those that do are scattered throughout the embryo.
TrlR85/+ enhances the position effect variegation at the w locus which is seen in In(1)wm4 flies.
4% of heterozygous adult males show transformation of A6 to A5.
Cytoplasmic actin filaments are completely absent in 18% of TrlR85 mutant egg chambers, and the nurse cell nuclei block the ring canals.
Trlen82/TrlR85 mutant females lay one or two eggs per day, compared to 30-50 in wild type females. The size of the eggs varies from 320 to 400 micrometres, which is small compared to >500 micrometres seen in wild type flies. The eggs are elliptical and have short chorionic appendages.
Structural abnormalities are seen in the ovaries of Trlen82/TrlR85 mutant females from stage 10 of egg chamber development. Follicle cells are often localized to the posterior part of the oocyte and do not cover the posterior surface. Abnormal migration of centripetal cells is also seen. Many egg chambers contain oocytes of an irregular shape and many oocytes are localized in the nurse cell region. Not all cytoplasm from the nurse cells is transferred to the oocyte in many egg chambers, resulting in a 'dumpless' phenotype. Numerous degrading egg chambers are seen with abnormal chromatin condensation in the nurse cells at stages 9 and 10. This is not usually seen in wild type. Most nurse cells demonstrate no significant abnormalities in the structure of cytoplasmic actin filaments formed before the phase of rapid transport at stage 10B, however these filaments look thinner, less organised and are less evenly distributed over the chamber. Cytoplasmic actin filaments are completely absent in 1.8% of egg chambers, and the nurse cell nuclei block the ring canals in these egg chambers.
TrlR85 homozygous larvae do not reach third instar. TrlR85/Trl13C larvae do develop till third instar, though their imaginal discs are very small. When TrlR85 germ-line clones are made, only very few progeny are obtained. The phenotype of the few progeny obtained is variable, ranging from unfertilised eggs in most cases to embryos developing cuticle with various defects. The unfertilised eggs exhibit a defect in micropyle formation. Those embryos that are fertilised have completely defective anterior, and denticle belts are not properly formed. When TrlR85 somatic clones are made (in a Minute background) various phenotypes are seen. In general most clones display a lack of bristles and no clones present any obvious homeotic transformations. Clones in the eyes, the proboscis and palpi sometimes reduce their sizes. In the thorax, the notum is often split and there is a clear disappearance of both macrochaetae and microchaetae. In the wing margin, clones running along the dorsal-ventral border usually delete the triple row of bristles. Clones in the wing blade, produce wings with blisters, reduced sizes, and a "held-out" phenotype is sometimes seen. In legs, most of the clones show a lack of bristles, in the first leg of males, clones show a reduction of the number of sex comb hairs which invariably is accompanied by a lack of surrounding bristles in the clones.
Heterozygotes do not have extra sex combs on the 2nd or 3rd leg and do not show transformation of antenna to leg.
Lethality occurs at hatching.
Does not effect position effect variegation at the bw locus caused by Byron.
Pairing sensitive repression is alleviated in iab-7 PRE lines that carry Trl13C.
Homozygotes die during the third larval instar with no obvious homeotic or other specific defects. Double homozygotes with z mutants show no cuticular defects.