DLH1, the Candida albicans homologue of the meiosis-specific DMC1, is not involved in DNA repair but catalyses spontaneous interhomologue recombination and might promote non-crossover events
DLH1, the Candida albicans homologue of the meiosis-specific DMC1, is not involved in DNA repair but catalyses spontaneous interhomologue recombination and might promote non-crossover events
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DOI：
10.1111/cmi.13137
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发表时间：
2019-11-11
影响因子：
3.4
通讯作者：
Larriba, German
中科院分区：
文献类型：
--
作者：
Ciudad, Toni;Bellido, Alberto;Larriba, German
DLH1，白念珠菌减数分裂特异性重组酶DMC1的同源基因，在有丝分裂周期中表达。DLH1-Delta表现为野生型(WT)，而RAD51-Delta表现为上位型。然而，DLH1-Delta在HIS4/HIS4(ChR4)基因座上显示自发杂合性缺失(LOH)的频率增加。对于WT和dlh1-Delta Delta，His的营养缺陷体主要是通过Chr4缺失和同源重组产生的，而RAD51-Delta和RAD51-Delta dlh1-Delta His(-)分离体主要是通过染色体丢失和截断形成的。少数RAD51-Delta，而不是RAD51-Delta dlh1-Delta，分离物出现了同源重组。在WT和dlh1-Delta中，GAL1/URA3基因座(ChR1，URA3替换1个GAL1等位基因)的LOH事件主要涉及长片段DNA。在DLH1-Delta中检测到少数短程LOH事件，但在DLH1-Delta中未检测到，并且这种DLH1-Delta表型部分地被WT DLH1等位基因所补充。在RAD51-Delta中，长程LOH事件也占主导地位，但其中约一半是由染色体截断引起的。我们认为，DLH1保守Dmc1谱系特异性氨基酸残基，可以促进链侵袭，并可能与RAD51一起调节白念珠菌有丝分裂非交叉的相对频率和转换道的长度。
DLH1, the Candida albicans orthologue of the meiosis-specific recombinase DMC1 was expressed during the mitotic cycle. In contrast to rad51-Delta Delta that displayed reduced growth rate and severe susceptibility to DNA-damaging agents, dlh1-Delta Delta behaved as wild type (WT), rad51-Delta Delta being was epistatic to dlh1-Delta Delta. However, dlh1-Delta Delta showed an increased frequency of spontaneous loss-of-heterozygosity (LOH) at the HIS4/his4 (Chr4) locus. For both WT and dlh1-Delta Delta, His auxotrophs arose via Chr4 loss and interhomologue recombination whereas rad51-Delta Delta and rad51-Delta Delta dlh1-Delta Delta His(-) segregants were formed mainly by chromosome loss and truncation. A few rad51-Delta Delta, but not rad51-Delta Delta dlh1-Delta Delta, segregants showed interhomologue recombination. LOH events at the GAL1/URA3 locus (Chr1; URA3 substitutes one GAL1 allele) in WT and dlh1-Delta Delta involved mainly long tracts of DNA. A few short-tract LOH events were detected in WT but not in dlh1-Delta Delta, and this dlh1-Delta Delta phenotype was partially complemented by a WT DLH1 allele. Long-tract LOH events were also predominant in rad51-Delta Delta, but about half of them arose via chromosome truncation. We suggest that Dlh1, which conserves the Dmc1 lineage-specific amino acid residues, can promote strand invasion and might regulate in combination with Rad51 the length of the conversion tracts and the relative frequencies of mitotic non-crossovers in C. albicans.