Amino acid replacement: W260term.
Nucleotide substitution: G?A.
G9118032A
G?A
W260term | Su(var)2-10-PA; W260term | Su(var)2-10-PB; W271term | Su(var)2-10-PC; W307term | Su(var)2-10-PD; W260term | Su(var)2-10-PE; W271term | Su(var)2-10-PF; W271term | Su(var)2-10-PG; W307term | Su(var)2-10-PH; W307term | Su(var)2-10-PI; W260term | Su(var)2-10-PJ; W271term | Su(var)2-10-PK; W307term | Su(var)2-10-PL; W307term | Su(var)2-10-PM; W307term | Su(var)2-10-PN
W260term
G to A nucleotide change at the second or third position of the wild type Trp codon leads to a nonsense mutation (exact site of mutation unspecified). The mutation was annotated at the second base of the codon.
interphase & nuclear chromosome (with Su(var)2-101)
Su(var)2-101/Su(var)2-102 mutants exhibit significant genome instability in larval neuroblasts (in the absence of ionizing radiation), including aneuploidy, chromosome fusions and changes in the number of satellites.
One copy of Su(var)2-102 strongly suppresses position effect variegation (PEV) at the w locus caused by In(1)wm4.
One copy of Su(var)2-102 moderately suppresses the telomeric position effect (TPE) in stocks carrying a variegating P{hsp26-pt-T}39C-5 insertion at the telomere of the left arm of chromosome two.
Causes dominant zygotic and maternal reductions in the transmission of Dp(1;f)J21A to offspring. A weak but reproducible decrease in transmission is seen when Su(var)2-102 is inherited from the father. When inherited from heterozygous mothers, zygotic and maternal defects combined to reduce Dp(1;f)J21A transmission levels to 8%. Su(var)2-101/Su(var)2-102 transheterozygous animals die as late larvae or early pupae, 3-15% of larvae have melanotic tumours. The structure and function of chromosomes in Su(var)2-101/Su(var)2-102 nutants are grossly abnormal in both males and females. Two major types of chromosome defects are observed: abnormally condensed chromosomes in metaphase and aberrantly segregating chromosomes in anaphase. Anaphase segregation defects include chromosome fragmentation and bridging. Penetrance of the metaphase defects are temperature sensitive. Salivary glands in Su(var)2-10Pex74a/Su(var)2-102 and Su(var)2-101/Su(var)2-102 mutants are reduced in size, and the consistent banding pattern of normal polytene chromosomes is severely disrupted. They are generally disorganised and abnormally condensed. In Su(var)2-101/Su(var)2-102 third instar larvae, interphase chromosome organisation is altered. telomere-telomere and telomere-lamina associations are disrupted in mutant nuclei.
