Amino acid replacement: C38Y.
Nucleotide substitution: G113A.
G17056620A
G113A
C38Y | tef-PA
C38Y
tefZ5864/Df(2R)P803-Δ15 males show a high level (39.7%) of fourth chromosome non-disjunction.
tefZ5864/tefk15914 males show a low level (4.3%) of fourth chromosome non-disjunction.
Homozygous males show a cytological defect in late prophase (S6) spermatocytes; separation of autosomal homologs is seen.
Homozygous males are fertile, but their progeny show paternal chromosome loss (loss rate of paternal chromosome 4 is 7%). The timing of the chromosome loss is meiotic.
Wild-type frequencies of sex and 4th chromosome nondisjunction are seen in homozygous females. Homozygous males show no increase in sex chromosome nondisjunction or loss compared to wild type. They show increased 4th chromosome nondisjunction compared to wild type. Nondisjunction of chromosomes 2 and 3 is also seen. The frequency of 4th chromosome nondisjunction or loss does not increase with age. The defect appears to be specific to meiosis I. The transmission of the Dp(1;f)1187 chromosome is unaffected in mutant males. Transmission of the C(4)RM chromosome is similar in mutant males and controls. In homozygous males, the homologues of either one or both of the autosomal bivalents are separate in 10% of S6 stage meiocytes (this phenotype is not seen in wild-type males). Unpaired autosomes are frequently seen in homozygous meiocytes, often at or near the spindle poles, whereas the sex bivalent is intact and often positioned medially between the poles. The precocious separation of the 4th chromosome bivalent appears exaggerated in mutant cells, as the 4th chromosomes often reach the spindle poles before the sex chromosomes have visibly separated. No defects in meiotic spindles are seen in mutant males. The chromosomes are dispersed along the pole-to-pole axis in stage M2 and M3. Autosomal bivalents with an unusual dumbbell-like shape or separated by a slight gap are seen, suggesting that they are not as tightly associated as in wild type. These bivalents are also often displaced from the metaphase plate. The sex chromosomes are closely apposed in a configuration not discernibly different from wild type.
tefZ5549/tefZ5864 is a suppressor of primary spermatocyte in meiotic anaphase I phenotype of Cap-H2Z3-0019/Cap-H2TH1
While 30.4% of anaphase I figures from Cap-H2Z3-0019/Cap-H2TH1 males are bridged, bridging is found within only 10.8% of anaphase I figures in a heterozygous tefZ5549/tefZ5864 background. In squashed preparations anaphase I bridging is decreased from 40.5% in Cap-H2Z3-0019/Cap-H2TH1 males to 25.6% in a heterozygous tefZ5549/tefZ5864 background.
The frequency of sex chromosome nondisjunction seen in males carrying Dp(2;Y)cb25-1, T(1;4)mscd1 or T(1;4)mscd2 is reduced if they are also homozygous for tefZ5864.
tefZ5864 is rescued by tefUAS.EGFP/Scer\GAL4T76
tefZ5864 is rescued by tefUAS.EGFP/Scer\GAL4T100
tefZ5864 is rescued by tefUAS.EGFP/Scer\GAL4T98
tefZ5864 is rescued by Scer\GAL4T110/tefUAS.EGFP
tefZ5864 is not rescued by Scer\GAL4T155/tefUAS.EGFP
tefZ5864 is not rescued by tefUAS.EGFP/Scer\GAL4c729
tefZ5864 is not rescued by tefUAS.EGFP/Scer\GAL4path-c135