Table of Contents
Advances in Evolutionary Biology
Volume 2014, Article ID 104683, 9 pages
http://dx.doi.org/10.1155/2014/104683
Review Article

Repetitive Sequence and Sex Chromosome Evolution in Vertebrates

Institute for Applied Ecology, University of Canberra, Canberra, ACT 2601, Australia

Received 14 May 2014; Accepted 3 September 2014; Published 11 September 2014

Academic Editor: Paul Harrison

Copyright © 2014 Tariq Ezaz and Janine E. Deakin. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Sex chromosomes are the most dynamic entity in any genome having unique morphology, gene content, and evolution. They have evolved multiple times and independently throughout vertebrate evolution. One of the major genomic changes that pertain to sex chromosomes involves the amplification of common repeats. It is hypothesized that such amplification of repeats facilitates the suppression of recombination, leading to the evolution of heteromorphic sex chromosomes through genetic degradation of Y or W chromosomes. Although contrasting evidence is available, it is clear that amplification of simple repetitive sequences played a major role in the evolution of Y and W chromosomes in vertebrates. In this review, we present a brief overview of the repetitive DNA classes that accumulated during sex chromosome evolution, mainly focusing on vertebrates, and discuss their possible role and potential function in this process.