Natural variation in meiotic recombination rate shapes introgression patterns in intraspecific hybrids between wild and domesticated barley

Citations Over TimeTop 10% of 2020 papers

Abstract

Meiotic recombination rates vary considerably between species, populations and individuals. The genetic exchange between homologous chromosomes plays a major role in evolution by breaking linkage between advantageous and deleterious alleles in the case of introgressions. Identifying recombination rate modifiers is thus of both fundamental and practical interest to understand and utilize variation in meiotic recombination rates. We investigated recombination rate variation in a large intraspecific hybrid population (named HEB-25) derived from a cross between domesticated barley and 25 wild barley accessions. We observed quantitative variation in total crossover number with a maximum of a 1.4-fold difference between subpopulations and increased recombination rates across pericentromeric regions. The meiosis-specific α-kleisin cohesin subunit REC8 was identified as a candidate gene influencing crossover number and patterning. Furthermore, we quantified wild barley introgression patterns and revealed how local and genome-wide recombination rate variation shapes patterns of introgression. The identification of allelic variation in REC8 in combination with the observed changes in crossover patterning suggest a difference in how chromatin loops are tethered to the chromosome axis, resulting in reduced crossover suppression across pericentromeric regions. Local and genome-wide recombination rate variation is shaping patterns of introgressions and thereby directly influences the consequences of linkage drag.

Related Papers

• → Cost–Benefit Analysis of Recombination and its Application for Understanding of Chiasma Interference(2001)14 cited
• → Chiasmata and chromosome breakages are related to crossing over in Drosophila ananassae males(2006)4 cited
• → Chiasma formation, crossing-over and recombination in meiosis(1994)11 cited
• [Cytogenetic study of synapsis and crossing-over in male mice heterozygous for reciprocal translocation T(14; 15)6Ca].(1990)
• → Estimating the Chiasma Frequency in Diplotene-Diakinesis Stage(2020)