Department of Genetics, University of Washington, Seattle, Washington 98195.
Genetics. 1973 Apr;73(4):531-41. doi: 10.1093/genetics/73.4.531.
Sporulating cells of Saccharomyces cerevisiae show an increasing sensitivity to ultraviolet irradiation. Maximum sensitivity is reached at a time comparable to meiotic prophase. Sensitivity is expressed as reduced sporulation after the irradiation. The uv effect can be efficiently reversed by photoreactivating light. Viability is also more severely affected during premeiotic DNA synthesis and during meiosis than in earlier stages in sporulation. Cells left in sporulation medium after the irradiation show a reduced viability compared with the cells plated immediately after the irradiation. Non-sporulating diploids do not acquire sensitivity when exposed to sporulation medium, hence the sensitivity is related to the sporulation process. That meiosis itself is affected, rather than spore formation alone, is evident from experiments in which the uv irradiation interferes with the uncovering of a recessive marker and with commitment to meiosis. It is proposed that during meiotic prophase, the DNA repair system is different from that found in vegetative cells.
出芽生殖的酿酒酵母细胞对紫外线照射的敏感性逐渐增加。最大的敏感性出现在类似于减数分裂前期的时间。敏感性表现为照射后的孢子形成减少。光复活光可以有效地逆转 uv 效应。在减数分裂前期 DNA 合成和减数分裂过程中，细胞的活力比出芽生殖的早期阶段受到更严重的影响。与照射后立即接种的细胞相比，照射后留在出芽生殖培养基中的细胞的存活率降低。当暴露于出芽生殖培养基时，非出芽生殖的二倍体不会获得敏感性，因此敏感性与出芽生殖过程有关。从 uv 照射干扰隐性标记的揭示和减数分裂的承诺的实验中可以明显看出，减数分裂本身受到影响，而不仅仅是孢子形成。有人提出，在减数分裂前期，DNA 修复系统与营养细胞中的修复系统不同。
