View at: Google Scholar T. Skaletsky, and D. Some recent models of the resolution of the intralocus sexual antagonism by gene duplication and the generation of a male-specific and a female-specific gene predict that accumulation of female-biased genes on the X chromosomes and male-biased genes on the autosomes is independent of the dominance effects and can account for the observed autosomal locations of male-biased genes [ ].
Eipper-Mains, B. Hoogerbrugge, J. The occurrence of X chromosome inactivation in the male germline has also been observed in worm [ 5643 ]. Bergero and D. Page, and J. Examples of these are accessory gland proteins and female reproductive proteases [ 83]. Although ectopic recombination does not always lead to reduced male fertility [ 53788687 ], fitness-reducing consequences of ampliconic structure are likely to be frequent enough to impose an upper limit on the number of duplicates that can be maintained in a Y chromosome as a higher number is expected to lead to more ectopic crossovers [ 88 ].
For instance, in the Drosophila pseudoobscura lineage, ancestral Muller elements A the current XL arm, homologous to the X chromosome in D. Nam, B. Forrest, V. Lopes, T. It has been suggested that the role of these palindromes on the sex chromosomes might be to prevent meiotic sex chromosome inactivation allowing the expression of spermatogenesis genes that reside in palindromes [ ].
Connallon and L. Additional models that may govern Y chromosome gene content likely include efficient sex-limited selection, selfish genetic elements, and subfunctionalization. Mita, and J. Out of these, 2 are sex chromosome XX or XY , and 44 are autosomes.