Department of Biology, Institute of Infectious Disease Research, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, ON L8S 4K1, Canada.
Curr Genet. 2010 Apr;56(2):163-76. doi: 10.1007/s00294-010-0289-z. Epub 2010 Feb 3.
In the basidiomycetous yeast Cryptococcus neoformans, fusants and meiotic progeny from haploid-haploid (HH) crosses between strains of mating type a (MAT a) and mating type alpha (MATalpha) typically inherit mitochondrial DNA (mtDNA) from the MAT a parent. In this study, we investigated the mtDNA inheritance pattern in haploid x non-haploid crosses. A total of 420 meiotic progeny and 173 fusants were obtained from five crosses and analyzed for two polymorphic mitochondrial markers. The percentage of meiotic progeny and fusants inheriting mtDNA from MATalpha or MATalpha/alpha parents ranged from 8 to 50%. The leakage was significantly greater than those observed in HH crosses, indicating that mtDNA inheritance is not uniparental in haploid x non-haploid crosses in C. neoformans. In addition, mtDNA leakage in the fusants, but not the meiotic progeny, of the MATalpha/alpha x MAT a cross was significantly higher than that in the MAT a/a x MATalpha cross, suggesting that the diploid parents with different mating types contribute differently in determining fusant mtDNA genotype in these crosses. Flow cytometry analysis revealed that meiotic progeny population of each cross was of mixed ploidy while the ploidy level of the selected fusants ranged from diploid to triploid.
在担子菌酵母新生隐球菌中，来自交配型 a (MAT a) 和交配型α (MATalpha) 菌株之间的单倍体-单倍体 (HH) 杂交的融合体和减数分裂后代通常从 MAT a 亲本继承线粒体 DNA (mtDNA)。在这项研究中，我们研究了单倍体 x 非单倍体杂交中的 mtDNA 遗传模式。从五个杂交中获得了总共 420 个减数分裂后代和 173 个融合体，并对两个多态性线粒体标记进行了分析。从 MATalpha 或 MATalpha/alpha 亲本遗传 mtDNA 的减数分裂后代和融合体的百分比范围为 8% 至 50%。漏出率明显高于 HH 杂交中观察到的漏出率，表明在新生隐球菌的单倍体 x 非单倍体杂交中，mtDNA 遗传不是单亲的。此外，在 MATalpha/alpha x MAT a 杂交的融合体中而不是在 MAT a/a x MATalpha 杂交的减数分裂后代中，mtDNA 漏出明显更高，表明不同交配型的二倍体亲本在这些杂交中融合体 mtDNA 基因型的决定中贡献不同。流式细胞术分析表明，每个杂交的减数分裂后代群体是混合倍性的，而选择的融合体的倍性水平从二倍体到三倍体不等。
