A reciprocal translocation radically reshapes sex-linked inheritance in the common frog

Mol Ecol. 2019 Apr;28(8):1877-1889. doi: 10.1111/mec.14990. Epub 2019 Apr 29.


X and Y chromosomes can diverge when rearrangements block recombination between them. Here we present the first genomic view of a reciprocal translocation that causes two physically unconnected pairs of chromosomes to be coinherited as sex chromosomes. In a population of the common frog (Rana temporaria), both pairs of X and Y chromosomes show extensive sequence differentiation, but not degeneration of the Y chromosomes. A new method based on gene trees shows both chromosomes are sex-linked. Furthermore, the gene trees from the two Y chromosomes have identical topologies, showing they have been coinherited since the reciprocal translocation occurred. Reciprocal translocations can thus reshape sex linkage on a much greater scale compared with inversions, the type of rearrangement that is much better known in sex chromosome evolution, and they can greatly amplify the power of sexually antagonistic selection to drive genomic rearrangement. Two more populations show evidence of other rearrangements, suggesting that this species has unprecedented structural polymorphism in its sex chromosomes.

Keywords: karyotype; recombination; sex chromosome; sexual antagonism; translocation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chromosome Inversion / genetics
  • Evolution, Molecular
  • Female
  • Genetic Linkage
  • Genome / genetics
  • Male
  • Rana temporaria / genetics*
  • Sex Chromosomes / genetics*
  • Sex Determination Processes / genetics*
  • X Chromosome
  • Y Chromosome