Cook K R, Murphy T D, Nguyen T C, Karpen G H
Molecular Biology and Virology Laboratory, Salk Institute for Biological Studies, La Jolla, California 92037, USA.
Genetics. 1997 Mar;145(3):737-47. doi: 10.1093/genetics/145.3.737.
Deletions in the Drosophila minichromosome Dp1187 were used to investigate the genetic interactions of trans-acting genes with the centromere. Mutations in several genes known to have a role in chromosome inheritance were shown to have dominant effects on the stability of minichromosomes with partially defective centromeres. Heterozygous mutations in the ncd and klp3A kinesin-like protein genes strongly reduced the transmission of minichromosomes missing portions of the genetically defined centromere but had little effect on the transmission of minichromosomes with intact centromeres. Using this approach, ncd and klp3A were shown to require only the centromeric region of the chromosome for their roles in chromosome segregation. Increased gene dosage also affected minichromosome transmission and was used to demonstrate that the nod kinesin-like protein gene interacts genetically with the centro mere, in addition to interacting with extracentromeric regions as demonstrated previously. The results presented in this study strongly suggest that dominant genetic interactions between mutations and centromere-defective minichromosomes could be used effectively to identify novel genes necessary for centromere function.
利用果蝇小染色体Dp1187中的缺失来研究反式作用基因与着丝粒的遗传相互作用。已知在染色体遗传中起作用的几个基因的突变，对具有部分缺陷着丝粒的小染色体的稳定性具有显性效应。ncd和klp3A驱动蛋白样蛋白基因中的杂合突变强烈降低了缺失遗传定义着丝粒部分的小染色体的传递，但对具有完整着丝粒的小染色体的传递影响很小。通过这种方法，已证明ncd和klp3A在染色体分离中的作用仅需要染色体的着丝粒区域。基因剂量增加也影响小染色体传递，并用于证明点头驱动蛋白样蛋白基因除了如先前所示与着丝粒外区域相互作用外，还与着丝粒发生遗传相互作用。本研究中呈现的结果强烈表明，突变与着丝粒缺陷小染色体之间的显性遗传相互作用可有效地用于鉴定着丝粒功能所必需的新基因。
