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allied
academies
Archives of Industrial Biotechnology | Volume 2
May 14-15, 2018 | Montreal, Canada
World Yeast Congress
A
llelic recombination due to meiotic crossovers is a major
driver of genome evolution, as well as a key player for
the selection of high-performing genotypes in economically
important species. To get more insights into crossover
regulation, we developed a high-throughput method to
measure recombination rate and crossover interference in 26
S. cerevisiae
strains representing a large part of the diversity
of the species. 15 intervals were monitored, covering
chromosomes VI and XI entirely, and part of chromosome I.
Average recombination rates and recombination landscapes
varied significantly across strains, and some regions
showed up to 9.5-fold variation. We observed interference
which varied across strains and was positively correlated
with crossover number. Recombination rate was strongly
and negatively correlated with whole-genome sequence
divergence between homologs, but less so when using solely
the sequences of the intervals probed for recombination
and even less so when using the sequences in the DSB rich
regions within these intervals, indicating that the negative
correlations are not explained by cis-effects only. Finally, to
investigate the genetic architecture of crossover rate, we
built an incomplete diallel design from five parental strains
and measured recombination in one region of chromosome
XI for 10 different hybrids. The results suggest that
recombination rate across hybrids may be mainly controlled
by the level of sequence divergence between parental strains
and by inbreeding effects, while additive effects of parental
alleles were hardly significant. These results open the way
to a better understanding of the genetic control of crossover
formation, as well as building more efficient designs for yeast
selection in industrial applications.
e:
matthieu.falque@inra.frIntraspecific diversity of recombination in
S. cerevisiae
Matthieu Falque
GQE– Le Moulon, INRA, Univ. Paris-Sud & Université Paris-Saclay, France