Recombination rate variation and infrequent sex influence genetic diversity in C. reinhardtii

Recombination confers a major evolutionary advantage by breaking up linkage disequilibrium (LD) between harmful and beneficial mutations,thereby facilitating selection. However, in species that are only periodically sexual, such as many microbial eukaryotes, the realized rate of recombination is also affected by the frequency of sex, meaning that infrequent sex can increase the effects of selection at linked sites despite high recombination rates. Despite this, the rate of sex of most facultatively sexual species is unknown. In this project, I am using population genomic data from natural populations of C. reinhardtii to examine fine-scale variation in the population recombination rate across the genome. Specifically, I hope to answer the following questions:

  1. What is the landscape of recombination rate variation across the genome of C. reinhardtii?
  2. What genomic features predict recombination rate variation in the genome?
  3. What is the rate of sex in natural populations of C. reinhardtii?
  4. How does recombination rate affect patterns of neutral diversity?