The relationship between the preference of mating type (MAT) and source in the opportunistic pathogen Talaromyces marneffei

Genome-wide comparisons have shown Talaromyces marneffei possessed a stable mating type locus in its meiosis genes. But the function of the mating type locus in T. marneffei is not clear. The potential sex recombination might lead to problems in clinical, such as the evolution of increased resistance to antifungal drugs and virulence. To determine the mating type in a sample of 107 T. marneffei isolates and to explore the possible relationship between fungus virulence and mating type or source. We used PCR analysis to determine the distribution of mating type genes and also analyzed the relationship between mating type and isolated sources (including HIV-positive patients, HIV-negative patients, bamboo rats, and the environment). Further, the Drosophila melanogaster model of infection was used to compare the differences of virulence in mating type and sources. Our results showed the entire sample population of T. marneffei with an overabundance of MAT1-2 alleles, but with a higher ratio of MAT1-1 in the isolates from HIV-negative patients. However, no significant differences in the survival of the D. melanogaster infected neither with MAT1-1 (6.5 days) nor MAT1-2 (4 days) isolates. Similar results were also observed in virulence analysis tested with different sources of isolates. So, we found that all isolates bore single mating type idiomorphs and unequal distribution. The distribution of the MAT genes seems related to different sources. And the virulence differences are independent of mating type genotype and source.Our work shows the entire sample population of 107 Talaromyces marneffei isolates with an overabundance of MAT1-2 alleles, but with a higher ratio of MAT1-1 in the isolates from HIV-negative patients. And fungus virulence is independent of mating type genotype and source in the Drosophila melanogaster model.