Maloisel Laurent, Bhargava Jaya, Roeder G Shirleen
Howard Hughes Medical Institute, Yale University, New Haven, Connecticut 06520-8103, USA.
Genetics. 2004 Jul;167(3):1133-42. doi: 10.1534/genetics.104.026260.
A screen for mutants of budding yeast defective in meiotic gene conversion identified a novel allele of the POL3 gene. POL3 encodes the catalytic subunit of DNA polymerase delta, an essential DNA polymerase involved in genomic DNA replication. The new allele, pol3-ct, specifies a protein missing the last four amino acids. pol3-ct shows little or no defect in DNA replication, but displays a reduction in the length of meiotic gene conversion tracts and a decrease in crossing over. We propose a model in which DNA synthesis determines the length of strand exchange intermediates and influences their resolution toward crossing over.
对减数分裂基因转换存在缺陷的芽殖酵母突变体进行筛选，鉴定出POL3基因的一个新等位基因。POL3编码DNA聚合酶δ的催化亚基，DNA聚合酶δ是参与基因组DNA复制的一种必需的DNA聚合酶。这个新等位基因pol3-ct编码的蛋白质缺失了最后四个氨基酸。pol3-ct在DNA复制中几乎没有缺陷，但减数分裂基因转换片段的长度缩短，交叉互换减少。我们提出了一个模型，其中DNA合成决定了链交换中间体的长度，并影响它们向交叉互换的转化。
