TY - JOUR
T1 - Per-Nucleus Crossover Covariation and Implications for Evolution
AU - Wang, Shunxin
AU - Veller, Carl
AU - Sun, Fei
AU - Ruiz-Herrera, Aurora
AU - Shang, Yongliang
AU - Liu, Hongbin
AU - Zickler, Denise
AU - Chen, Zijiang
AU - Kleckner, Nancy
AU - Zhang, Liangran
PY - 2019/4/4
Y1 - 2019/4/4
N2 - © 2019 Elsevier Inc. Crossing over is a nearly universal feature of sexual reproduction. Here, analysis of crossover numbers on a per-chromosome and per-nucleus basis reveals a fundamental, evolutionarily conserved feature of meiosis: within individual nuclei, crossover frequencies covary across different chromosomes. This effect results from per-nucleus covariation of chromosome axis lengths. Crossovers can promote evolutionary adaptation. However, the benefit of creating favorable new allelic combinations must outweigh the cost of disrupting existing favorable combinations. Covariation concomitantly increases the frequencies of gametes with especially high, or especially low, numbers of crossovers, and thus might concomitantly enhance the benefits of crossing over while reducing its costs. A four-locus population genetic model suggests that such an effect can pertain in situations where the environment fluctuates: hyper-crossover gametes are advantageous when the environment changes while hypo-crossover gametes are advantageous in periods of environmental stasis. These findings reveal a new feature of the basic meiotic program and suggest a possible adaptive advantage. Crossover formation covaries within gametes generated by meiosis, leading to gametes with either many or few total crossovers, potentially representing a meiotic bet-hedging strategy to balance the evolutionarily advantages of recombination with its inherent risk.
AB - © 2019 Elsevier Inc. Crossing over is a nearly universal feature of sexual reproduction. Here, analysis of crossover numbers on a per-chromosome and per-nucleus basis reveals a fundamental, evolutionarily conserved feature of meiosis: within individual nuclei, crossover frequencies covary across different chromosomes. This effect results from per-nucleus covariation of chromosome axis lengths. Crossovers can promote evolutionary adaptation. However, the benefit of creating favorable new allelic combinations must outweigh the cost of disrupting existing favorable combinations. Covariation concomitantly increases the frequencies of gametes with especially high, or especially low, numbers of crossovers, and thus might concomitantly enhance the benefits of crossing over while reducing its costs. A four-locus population genetic model suggests that such an effect can pertain in situations where the environment fluctuates: hyper-crossover gametes are advantageous when the environment changes while hypo-crossover gametes are advantageous in periods of environmental stasis. These findings reveal a new feature of the basic meiotic program and suggest a possible adaptive advantage. Crossover formation covaries within gametes generated by meiosis, leading to gametes with either many or few total crossovers, potentially representing a meiotic bet-hedging strategy to balance the evolutionarily advantages of recombination with its inherent risk.
KW - chromosome axis legngth
KW - chromosome loops
KW - crossover
KW - crossover covariation
KW - crossover variance
KW - evolution of recombination
KW - evolution of sex
KW - genome-wide recombination rate
KW - meiosis
KW - recombination
U2 - 10.1016/j.cell.2019.02.021
DO - 10.1016/j.cell.2019.02.021
M3 - Article
C2 - 30879787
VL - 177
SP - 326-338.e16
JO - Cell
JF - Cell
SN - 0092-8674
ER -