Sekelsky J J, McKim K S, Messina L, French R L, Hurley W D, Arbel T, Chin G M, Deneen B, Force S J, Hari K L, Jang J K, Laurençon A C, Madden L D, Matthies H J, Milliken D B, Page S L, Ring A D, Wayson S M, Zimmerman C C, Hawley R S
Department of Genetics, Section of Molecular and Cellular Biology, University of California, Davis, California 95616, USA.
Genetics. 1999 Jun;152(2):529-42. doi: 10.1093/genetics/152.2.529.
The segregation of homologous chromosomes from one another is the essence of meiosis. In many organisms, accurate segregation is ensured by the formation of chiasmata resulting from crossing over. Drosophila melanogaster females use this type of recombination-based system, but they also have mechanisms for segregating achiasmate chromosomes with high fidelity. We describe a P-element mutagenesis and screen in a sensitized genetic background to detect mutations that impair meiotic chromosome pairing, recombination, or segregation. Our screen identified two new recombination-deficient mutations: mei-P22, which fully eliminates meiotic recombination, and mei-P26, which decreases meiotic exchange by 70% in a polar fashion. We also recovered an unusual allele of the ncd gene, whose wild-type product is required for proper structure and function of the meiotic spindle. However, the screen yielded primarily mutants specifically defective in the segregation of achiasmate chromosomes. Although most of these are alleles of previously undescribed genes, five were in the known genes alphaTubulin67C, CycE, push, and Trl. The five mutations in known genes produce novel phenotypes for those genes.
同源染色体彼此分离是减数分裂的本质。在许多生物体中，交叉互换产生的交叉点确保了精确分离。黑腹果蝇雌性利用这种基于重组的系统，但它们也有机制以高保真度分离无交叉点染色体。我们描述了在一个敏感遗传背景下进行的P因子诱变和筛选，以检测损害减数分裂染色体配对、重组或分离的突变。我们的筛选鉴定出两个新的重组缺陷突变：mei-P22，它完全消除减数分裂重组；mei-P26，它以极性方式使减数分裂交换减少70%。我们还获得了ncd基因的一个不寻常等位基因，其野生型产物是减数分裂纺锤体正常结构和功能所必需的。然而，筛选主要产生了在无交叉点染色体分离中特异性缺陷的突变体。尽管其中大多数是以前未描述基因的等位基因，但有五个位于已知基因alphaTubulin67C、CycE、push和Trl中。已知基因中的这五个突变产生了这些基因的新表型。
