Mutations in New Cell Cycle Genes That Fail to Complement a Multiply Mutant Third Chromosome of Drosophila

[摘要] We have simultaneously screened for new alleles and second site mutations that fail to complement five cell cycle mutations of Drosophila carried on a single third chromosome ( gnu, polo, mgr, asp, stg ). Females that are either transheterozygous for scott of the antartic ( scant ) and polo , or homozygous for scant produce embryos that show mitotic defects. A maternal effect upon embryonic mitoses is also seen in embryos derived from females transheterozygous with helter skelter ( hsk ) and either mgr or asp. deopatra ( cleo ), fails to complement asp but is not uncovered by a deficiency for asp. The mitotic phenotype of larvae heterozygous for cleo and the multiple mutant chromosome is similar to weak alleles of asp , but there are no defects in male meiosis. Mutations that failed to complement stg fell into two complementation groups corresponding to stg and a new gene noose . Three of the new stg alleles are early zygotic lethals, whereas the fourth is a pharate adult lethal allele that affects both mitosis and meiosis. Mutations in noose fully complement a small deficiency that removes stg, but when placed in trans to certain stg alleles, result in late lethality and mitotic abnormalities in larval brains.

[学科分类] 医学（综合）