Amino acid replacement (H to Y) at a position that corresponds to residue 145 in the A isoform, residue 446 in the B isoform, and residue 491 in the C isoform.
Amino acid replacement (D to E) at a position that corresponds to residue 766 in the A isoform, residue 1067 in the B isoform, and residue 1112 in the C isoform.
Amino acid replacement (A to T) at a position that corresponds to residue 782 in the A isoform, residue 1083 in the B isoform, and residue 1128 in the C isoform.
C22813545T
H491Y | stl-PC; H491Y | stl-PE
H145Y
H446Y
H491Y
2R_r5:18701050..18701050
Site of nucleotide substitution in mutant inferred by FlyBase based on reported amino acid change. One of 3 amino acid substitutions in mutant. The amino acid sequence changes were reported with respect to three alternative transcripts.
G22815735A
A1128T | stl-PC; A1128T | stl-PE
A782T
A1083T
A1128T
2R_r5:18703240..18703240
Site of nucleotide substitution in mutant inferred by FlyBase based on reported amino acid change. One of 3 amino acid substitutions in mutant. The amino acid sequence changes were reported with respect to three alternative transcripts.
T22815689R
D1112E | stl-PC; D1112E | stl-PE
D766E
D1067E
D1112E
2R_r5:18703194..18703194
Site of nucleotide substitution in mutant inferred by FlyBase based on reported amino acid change. One of 3 amino acid substitutions in mutant. The amino acid sequence changes were reported with respect to three alternative transcripts.
Ovarioles from young mutant females (1 day post-eclosion) lack any individualized follicles and interfollicular stalks, instead, multiple germline cysts are enclosed in a single somatic epithelium.
Homozygous and stl8-1204/stl3 ovarioles in adult females lack the interfollicular stalks that normally separate adjacent wild-type follicles. This phenotype results from failed follicle individualisation, rather than from persistent germline cell division, because mutant ovarioles contain germ cells at varying stages of maturation and groups of 16 interconnected germ cells that would correspond to a single germline cyst in wild-type are still recognisable. Degeneration is seen in the mutant ovarioles, which increases with age, and both germline and somatic cells appear to degenerate. Germline clonal analysis suggests that stl function is not required in the germline for normal follicle morphogenesis; ovarioles containing a mutant germline form normally maturing, discrete follicles. Homozygous somatic clones in the ovariole can be recovered. Mutant clones in somatic epithelial cells are variably associated with follicular defects. Severe stl-like follicle formation defects are most often associated with very large somatic homozygous clones in the ovary, but not every large mutant clone in the ovary results in severe defects. The mosaic analysis also suggests that weak follicular defects are often due to an effect of nonovarian mutant clones. Wild-type ovaries transplanted into the abdomens of homozygous male hosts show severe morphological defects (wild-type ovaries transplanted into the abdomens of wild-type male hosts are morphologically normal).
Ultrastructural studies reveal that oogonial cysts appear to be normal; surrounded by wedge-shaped follicle cells but not separated by interfollicular stalks so that the conventional moniliform vitellarium is not observed. Posterior end of ovariole filled with fusing follicles.
Group III phenotype: females lay no eggs and show ovaries with abnormal size and/or oocyte content.
da2 stl8-1204 double heterozygotes show severe morphological defects in all ovarioles. 65% of das22 stl8-1204 double heterozygotes have ovariole defects. dalyh stl8-1204 double heterozygotes do not show ovariole defects. 85% of Dp(2;Y)cb50 ; dalyh stl8-1204/Df(2L)J27 ovarioles are normal, with the remaining 15% only having mild defects.
