Harris J F, Whitmore G F
Somatic Cell Genet. 1977 Mar;3(2):173-93. doi: 10.1007/BF01551813.
The process of segreation or phenotypic expression of two recessive drug-resistant loci from heterozygous Chinese hamster ovary hybrid lines is examined. The spontaneous segregation rates of phytohaemagglutinin resistance (Phar) and a temperature-dependent 8-azaguanine-resistant locus (Azarts) from heterozygous quasitetraploid lines using Luria-Delbruck fluctuation analysis were 5 X 10(-5) and 10(-5) events/cell/generation, respectively. In quasihexaploid lines, the latter rates increased 40- and 200-fold, respectively, and were dependent on the number of presumptive drug-sensitive allelel. The mutagens EMS, MNNG, ICR-170, ICR-191, and gamma rays significantly increased the frequency of segregation events. The mutagen-induced frequency of dominant mutations to ouabain (Ouar) and alpha-amanitin (Amar) rsistance in the same hybrid line was much lower in comparison to segregation events and was mutagen specific. The chromosome number per metaphase cell was more variable than DNA content in quasitetraploid lines. These properties of marker segregation are consistent with mechanisms of either restricted chromosome loss, rearrangement, or mutation.
研究了来自杂合中国仓鼠卵巢杂交系的两个隐性抗药基因座的分离或表型表达过程。使用卢里亚 - 德尔布吕克波动分析，从杂合准四倍体系中分离出植物血凝素抗性（Phar）和温度依赖性8 - 氮杂鸟嘌呤抗性基因座（Azarts）的自发分离率分别为5×10^(-5)和10^(-5)事件/细胞/代。在准六倍体系中，后者的分离率分别增加了40倍和200倍，并且取决于假定的药物敏感等位基因的数量。诱变剂EMS、MNNG、ICR - 170、ICR - 191和γ射线显著增加了分离事件的频率。与分离事件相比，在同一杂交系中诱变剂诱导的对哇巴因（Ouar）和α - 鹅膏蕈碱（Amar）抗性的显性突变频率要低得多，并且具有诱变剂特异性。在准四倍体系中，每个中期细胞的染色体数比DNA含量更具变异性。标记分离的这些特性与受限染色体丢失、重排或突变的机制一致。
