Brain cells are hyperploid. Aneuploidy involves improper chromosome segregation at anaphase: precocious sister chromatid separation. Mitotic index and the ratio of numbers of cells in anaphase relative to the total number of mitotic figures in larval brains is similar in wild type. Lethal phenotype can be rescued by P element mediated transformation of a wild type mit(1)15 gene copy.
Chromosome behaviour in the wing and abdominal cells is abnormal; an increased frequency of homozygous mwh- clones is seen in the wings of mit(1)1515/Y;mwh-/+ males, and an increased frequency of y- mwh- twin spots in the abdomen of mit(1)1515/Y;T(1;3)scJ4, y+ mwh-/+ males. A high frequency of larval neuroblasts are hyperploid for one or more chromosomes.
temperature-sensitive