Käfer E, Mayor O
Mutat Res. 1986 Jul;161(2):119-34. doi: 10.1016/0027-5107(86)90003-5.
To identify genes which affect DNA repair and possibly recombination in Aspergillus nidulans, mutants hypersensitive to methyl methanesulphonate (MMS) were induced with ultraviolet light (UV) or gamma-rays. About half of them contained associated translocations and many were hypersensitive to UV and/or defective in meiosis. Two are alleles of the known uvsB gene while most others define new genes. In addition, among available uvs mutants many were found to be MMS-sensitive. Some of the various uncharacterized ones were identified as alleles of known uvs, but 5 of them were mapped in 2 new genes, uvsH and uvsJ. To identify functional and epistatic groups, mutants from each uvs gene were tested for effects on recombination and mutation, and double mutant uvs strains were compared for UV survival to their component single mutant strains. 3 epistatic pairs were identified, (1) uvsF and H, (2) uvsB and D, and (3) uvsC and E. Conclusive interpair tests were difficult, because such double mutant combinations were frequently lethal or nearly so. The first pair, uvsF and H, shared some of the properties of excision-defective mutants, both uvs being very highly sensitive to UV for mutation as well as survival. But unlike such mutants, uvsH was also sensitive to gamma-rays and defective in meiosis. Both uvs showed normal levels of meiotic recombination, but greatly increased spontaneous mitotic crossing-over, being the most "hyperrec" types among all uvs. The second pair, uvsB and uvsC, which was similarly hyperrec showed only slight increases of UV-induced mutation (less than 2-fold). As a main effect, these uvs caused very high frequencies of unbalanced, unstable segregants from diploid conidia (30 X), but few of these were recognizable aneuploids. The third pair, uvsC and E, which are known to be rec- for gene conversion, caused reduced mitotic crossing-over in diploids and increased levels of haploid segregants. These mutants are spontaneous mutators, but showed less UV-induced mutation than wild-type controls.
为了鉴定影响构巢曲霉DNA修复及可能的重组的基因，用紫外线（UV）或γ射线诱导对甲磺酸甲酯（MMS）敏感的突变体。其中约一半含有相关的易位，许多对UV敏感和/或减数分裂有缺陷。其中两个是已知uvsB基因的等位基因，而大多数其他基因定义了新基因。此外，在现有的uvs突变体中，发现许多对MMS敏感。一些未表征的突变体被鉴定为已知uvs的等位基因，但其中5个定位于2个新基因uvsH和uvsJ中。为了鉴定功能和上位性组，测试了每个uvs基因突变体对重组和突变的影响，并比较了双突变uvs菌株与它们的单突变组分菌株的UV存活率。鉴定出3对上位性对，（1）uvsF和H，（2）uvsB和D，以及（3）uvsC和E。成对间的确证测试很困难，因为这种双突变体组合经常是致死的或近乎致死的。第一对，uvsF和H，具有一些切除缺陷型突变体的特性，两个uvs对UV诱导的突变和存活都非常敏感。但与这类突变体不同，uvsH对γ射线也敏感，并且减数分裂有缺陷。两个uvs的减数分裂重组水平正常，但自发有丝分裂交换大大增加，是所有uvs中最“超重组”的类型。第二对，uvsB和uvsC，同样是超重组的，仅显示UV诱导突变略有增加（小于2倍）。作为主要影响，这些uvs导致来自二倍体分生孢子的不平衡、不稳定分离子的频率非常高（30倍），但其中很少是可识别的非整倍体。第三对，uvsC和E，已知对基因转换是rec-，导致二倍体中有丝分裂交换减少和单倍体分离子水平增加。这些突变体是自发突变体，但与野生型对照相比，UV诱导的突变较少。
