Genome-wide maps of recombination and chromosome segregation in human oocytes and embryos show selection for maternal recombination rates

Nat Genet. 2015 Jul;47(7):727-735. doi: 10.1038/ng.3306. Epub 2015 May 18.

Abstract

Crossover recombination reshuffles genes and prevents errors in segregation that lead to extra or missing chromosomes (aneuploidy) in human eggs, a major cause of pregnancy failure and congenital disorders. Here we generate genome-wide maps of crossovers and chromosome segregation patterns by recovering all three products of single female meioses. Genotyping >4 million informative SNPs from 23 complete meioses allowed us to map 2,032 maternal and 1,342 paternal crossovers and to infer the segregation patterns of 529 chromosome pairs. We uncover a new reverse chromosome segregation pattern in which both homologs separate their sister chromatids at meiosis I; detect selection for higher recombination rates in the female germ line by the elimination of aneuploid embryos; and report chromosomal drive against non-recombinant chromatids at meiosis II. Collectively, our findings show that recombination not only affects homolog segregation at meiosis I but also the fate of sister chromatids at meiosis II.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cells, Cultured
  • Chromosome Mapping
  • Chromosome Segregation*
  • Crossing Over, Genetic
  • Female
  • Genome, Human
  • Humans
  • Meiosis
  • Oocytes / physiology
  • Polar Bodies
  • Polymorphism, Single Nucleotide
  • Recombination, Genetic*
  • Sequence Analysis, DNA