Eur. Phys. J. B 50, 613-615 (2006)
https://doi.org/10.1140/epjb/e2006-00167-0

Mathematical glimpse on the Y chromosome degeneration

Instituto de Física Teórica, Universidade Estadual Paulista, Rua Pamplona 145, 01405-900 São Paulo, SP, Brazil

Corresponding author: ^a lobo@ft.org.br

Received: 3 August 2005
Revised: 25 October 2005
Published online: 5 May 2006

Abstract

The Y chromosomes are genetically degenerate and do not recombine with their matching partners X. Non-recombination of XY pairs has been pointed out as the key factor for the degeneration of the Y chromosome. The aim here is to show that there is a mathematical asymmetry in sex chromosomes which leads to the degeneration of Y chromosomes even in the absence of XX and XY recombination. A model for sex-chromosome evolution in a stationary regime is proposed. The consequences of their asymmetry are analyzed and lead us to a couple of conclusions. First, Y chromosome degeneration shows up more often than X chromosome degeneration. Second, if nature prohibits female mortalities from beeing exactly , then Y chromosome degeneration is inevitable.