Isolation of aneuploid-generating mutants of Aspergillus nidulans, one of which is defective in interphase of the cell cycle.
Isolation of aneuploid-generating mutants of Aspergillus nidulans, one of which is defective in interphase of the cell cycle.
复制标题
构巢曲霉非整倍体突变体的分离，其中一种突变体在细胞周期间期存在缺陷。
DOI：
10.1093/genetics/108.1.107
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发表时间：
1984
期刊：
影响因子：
3.3
通讯作者：
Mortimore,ID
中科院分区：
文献类型：
--
作者：
Upshall,A;Mortimore,ID
描述了一种分离在涉及有丝分裂染色体分离的基因座上潜在缺陷的突变体的方法。条件致死、热敏感(42°)突变体在37°次限制性温度下进行检测，以产生显示整个染色体非整倍体的表型和行为模式的膨胀菌落。在14个突变体中，3个对一种二体表型表现出专一性，而11个对不同的非整倍体表型产生了集落镶嵌。后者被称为HFA(非整倍体的高频)。对于11个突变体中的10个，温度敏感性和非整倍体产量是共分离的，表明每个突变体中都有一个突变。这些突变为隐性突变和非等位基因突变。分析集中在hfaB3突变上，该突变被定位在与该基因座紧密连锁的VI染色体上。HfaB3对37°有丝分裂的破坏性影响表现为：(1)多标记纯合子B3二倍体获得的表型非整倍体群体的分裂区段标记的倍性和整体染色体类型分离；(2)来自绿孢子纯合二倍体的自发性黄孢子性异交重组体中出现高频率的单倍体和非分离二倍体分离体。该突变对37°的减数分裂染色体分离没有影响。胚胎中42°的单个间期核，加上温度交换实验中有丝分裂指数的变化，表明hfaB3在限制性温度下使细胞周期停滞在间期。得出的结论是，hfaB基因产物是进入有丝分裂和分裂核中正常染色体分离所必需的。
A method is described for isolating mutants potentially defective in loci involved in mitotic chromosome segregation. Conditional lethal, heat-sensitive (42°) mutants were assayed at a subrestrictive temperature of 37° for an inflated production of colonies displaying phenotypes and behavior patterns of whole chromosome aneuploids. Of 14 mutants, three showed specificity for one disomic phenotype, whereas 11 generated colonies mosaic for different aneuploid phenotypes. This latter group is designatedhfa(high frequency of aneuploid). For ten of the 11 mutants temperature sensitivity and aneuploid production cosegregated, indicating a single mutation in each. These mutations were recessive and nonallelic. Analysis was concentrated on thehfaB3mutation which is mapped to chromosomeVItightly linked to themethBandtsBloci. The disruptive influence ofhfaB3on mitosis at 37° was shown by (1) ploidy and whole chromosome-type segregation of markers in the breakdown sectors of phenotypically aneuploid colonies obtained from multiply marked homozygoushfaB3disploids; (2) a high frequency of haploid and nondisjunctional diploid segregants among spontaneous yellow-spored parasexual recombinants taken from green-spored homozygoushfaB3diploids. The mutation had no effect on meiotic chromosome segregation at 37°. The single interphase nucleus in germlings at 42°, coupled with changes in the mitotic index in temperature exchange experiments, showedhfaB3to arrest the cell cycle in interphase at restrictive temperature. A conclusion drawn is that thehfaBgene product is required both for entry into mitosis and for normal chromosome segregation in dividing nuclei.