| Biology of Genomes |  |
Journal articles
Population genomics reveals chromosome-scale heterogeneous evolution in a protoploid yeast
Abstract : Yeast species represent an ideal model system for population genomic studies but large-scale polymorphism surveys have only been reported for species of the Saccharomyces genus so far. Hence, little is known about intraspecific diversity and evolution in yeast. To obtain a new insight into the evolutionary forces shaping natural populations, we sequenced the genomes of an expansive worldwide collection of isolates from a species distantly related to S. cerevisiae: Lachancea kluyveri (formerly Saccharomyces kluyveri). We identified 6.5 million SNPs and showed that a large introgression event of 1-Mb of GC-rich sequence in the chromosomal arm probably occurred in the last common ancestor of all L. kluyveri strains. Our population genomic data clearly revealed that this 1-Mb region underwent a molecular evolution pattern very different from the rest of the genome. It is characterized by a higher recombination rate, with a dramatically elevated A:T→G:C substitution rate, which is the signature of an increased GC-biased gene conversion. In addition, the predicted base composition at equilibrium demonstrates that the chromosome-scale compositional heterogeneity will persist after the genome has reached mutational equilibrium. Altogether, the data presented herein clearly show that distinct recombination and substitution regimes can coexist and lead to different evolutionary patterns within a single genome.
Cited literature [43 references]
https://hal.sorbonne-universite.fr/hal-01087685
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Submitted on : Wednesday, November 26, 2014 - 2:56:38 PM
Last modification on : Thursday, September 2, 2021 - 9:06:25 AM
Long-term archiving on: : Friday, February 27, 2015 - 12:25:57 PM
Contributor : Hal Sorbonne Université Administateur Connect in order to contact the contributor
Submitted on : Wednesday, November 26, 2014 - 2:56:38 PM
Last modification on : Thursday, September 2, 2021 - 9:06:25 AM
Long-term archiving on: : Friday, February 27, 2015 - 12:25:57 PM
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