Divergence, hybridization, and recombination in the mitochondrial genome of the human pathogenic yeast Cryptococcus gattii |
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Authors: | JIANPING XU† ZHUN YAN‡ HONG GUO† |
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Institution: | Department of Biology, and Institute of Infectious Disease Research, Michael G. DeGroote School of Medicine, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4K1;, Central Research Laboratory, Hainan Medical College, Haikou, Hainan, 571101, China |
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Abstract: | The inheritance of mitochondrial genes and genomes are uniparental in most sexual eukaryotes. This pattern of inheritance makes mitochondrial genomes in natural populations effectively clonal. Here, we examined the mitochondrial population genetics of the emerging human pathogenic fungus Cryptococcus gattii . The DNA sequences for five mitochondrial DNA fragments were obtained from each of 50 isolates belonging to two evolutionary divergent lineages, VGI and VGII. Our analyses revealed a greater sequence diversity within VGI than that within VGII, consistent with observations of the nuclear genes. The combined analyses of all five gene fragments indicated significant divergence between VGI and VGII. However, the five individual genealogies showed different relationships among the isolates, consistent with recent hybridization and mitochondrial gene transfer between the two lineages. Population genetic analyses of the multilocus data identified evidence for predominantly clonal mitochondrial population structures within both lineages. Interestingly, there were clear signatures of recombination among mitochondrial genes within the VGII lineage. Our analyses suggest historical mitochondrial genome divergence within C. gattii , but there is evidence for recent hybridization and recombination in the mitochondrial genome of this important human yeast pathogen. |
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Keywords: | population genetics gene genealogy hybridization dispersion mitochondrial recombination C gattii |
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