Istituto di Genetica Biochimica ed Evoluzionistica del C.N.R., Via Abbiategrasso 207, I-27100, Pavia, Italy.
Cytotechnology. 1987 Oct;1(1):91-4. doi: 10.1007/BF00351131.
Three UV sensitive (UV(s)) mutants (CHO43RO, CHO423PV, CHO30PV), characterized by different levels of reduction in their ability to perform unscheduled DNA synthesis (UDS), were analysed for spontaneous and UV-induced frequency of chromosomal aberrations and for sensitivity to alkylating agents. The baseline frequency of chromosomal aberrations was in the normal range, whereas after UV irradiation a positive correlation between the degree of UV sensitivity and the rate of chromosomal breakage was observed. Survival experiments after mutagen exposure indicated that the UV(s) clones are characterized by different levels of hypersensitivity to bifunctional alkylating agents whereas the sensitivity to monofunctional alkylating agents is in the normal range. Genetic analysis performed by measuring the survival after UV in hybrids produced by fusing UV(s) cells with wild-type or UV(s) cells belonging to the six Chinese hamster complementation groups, indicated that the three clones carry recessive mutations and belong to c.g. 2. These findings suggest that defects in the same gene may result in different degrees of phenotypic alterations.
三种对紫外线敏感（UV(s)）的突变体（CHO43RO、CHO423PV、CHO30PV），其特征是进行非计划 DNA 合成（UDS）的能力不同程度降低，对它们的自发和紫外线诱导的染色体畸变频率以及对烷化剂的敏感性进行了分析。染色体畸变的基线频率在正常范围内，而在紫外线照射后，观察到紫外线敏感性的程度与染色体断裂的速率之间存在正相关。诱变后存活实验表明，UV(s)克隆的特点是对双功能烷化剂的敏感性不同程度增加，而对单功能烷化剂的敏感性在正常范围内。通过测量融合 UV(s)细胞与野生型或属于六个中国仓鼠互补群的 UV(s)细胞产生的杂种在紫外线照射后的存活率来进行的遗传分析表明，这三个克隆携带隐性突变，属于 c.g.2。这些发现表明，同一基因的缺陷可能导致不同程度的表型改变。
