A High-Resolution Map of Meiotic Recombination in Cryptococcus deneoformans Demonstrates Decreased Recombination in Unisexual Reproduction

Genetics: A Periodical Record of Investigations Bearing on Heredity and Variation

Cullen Roth^1¹  R. Blake Billmyre^3³  Paul M. Magwene^4⁴  Joseph Heitman^2⁵  Sheng Sun^2⁶ 

[1] Department of Biology, Duke University, Durham, North Carolina 27708;Department of Biology, Duke University, Durham, North Carolina 27708^4;Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710^2;Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710^3;University Program in Genetics and Genomics, Duke University, Durham, North Carolina 27708;University Program in Genetics and Genomics, Duke University, Durham, North Carolina 27708^1

关键词: unisexual reproduction;    whole-genome sequencing;    genome-wide recombination map;    crossover hot spots;    allele segregation distortion;   

DOI  :  10.1534/genetics.118.300996

学科分类：医学（综合）

来源: Genetics Society of America

【 摘 要 】

Multiple species within the basidiomycete genus Cryptococcus cause cryptococcal disease. These species are estimated to affect nearly a quarter of a million people leading to ∼180,000 mortalities, annually. Sexual reproduction, which can occur between haploid yeasts of the same or opposite mating type, is a potentially important contributor to pathogenesis as recombination can generate novel genotypes and transgressive phenotypes. However, our quantitative understanding of recombination in this clinically important yeast is limited. Here, we describe genome-wide estimates of recombination rates in Cryptococcus deneoformans and compare recombination between progeny from α–α unisexual and a –α bisexual crosses. We find that offspring from bisexual crosses have modestly higher average rates of recombination than those derived from unisexual crosses. Recombination hot and cold spots across the C. deneoformans genome are also identified and are associated with increased GC content. Finally, we observed regions genome-wide with allele frequencies deviating from the expected parental ratio. These findings and observations advance our quantitative understanding of the genetic events that occur during sexual reproduction in C. deneoformans , and the impact that different forms of sexual reproduction are likely to have on genetic diversity in this important fungal pathogen.

【 授权许可】

CC BY