Open AccessSEX CHROMOSOME TRANSLOCATIONS IN THE EVOLUTION OF REPRODUCTIVE ISOLATION
Author(s) -
Martin L. Tracey
Publication year - 1972
Publication title -
genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.792
H-Index - 246
eISSN - 1943-2631
pISSN - 0016-6731
DOI - 10.1093/genetics/72.2.317
Subject(s) - biology , heterogametic sex , chromosomal translocation , genetics , fixation (population genetics) , sterility , chromosome , reproductive isolation , evolution of sexual reproduction , y chromosome , x chromosome , autosome , evolutionary biology , gene , population , demography , sociology
Haldane's rule states that in organisms with differentiated sex chromosomes, hybrid sterility or inviability is generally expressed more frequently in the heterogametic sex. This observation has been variously explained as due to either genic or chromosomal imbalance. The fixation probabilities and mean times to fixation of sex-chromosome translocations of the type necessary to explain Haldane's rule on the basis of chromosomal imbalance have been estimated in small populations of Drosophila melanogaster. The fixation probability of an X chromosome carrying the long arm of the Y(X.Y(L)) is approximately 30% greater than expected under the assumption of no selection. No fitness differences associated with the attached Y(L) segment were detected. The fixation probability of a deficient Y chromosome is 300% greater than expected when the X chromosome contains the deleted portion of the Y. It is suggested that sex-chromosome translocations may play a role in the establishment of reproductive isolation.