Gonadal expression of aromatase and estrogen receptor alpha genes in two races of Tunisian mice and their hypofertile hybrids.

Genetic Laboratory, Genetic Biodiversity and Bioresources Valorization, Higher Institute of Biotechnology, Monastir, TunisiaReceived: 10 February 2007; accepted 30 June 2007SUMMARYHouse mice (Mus musculus domesticus) in Tunisia consists of two races, one carries the 40-acrocentric standard karyotypes and the other one is a robertsonian race (2n=22) homozygous for nine centric fusions (Rb). The F1 hybrids between the two chromosomal races showed a significantdecrease in reproductive success and litter size. Such results can be related to the formation of meiotic trivalent in the hybrids leading to the production of viable aneuploid gametes and post-zygotic elimination of embryos due to chromosomal non disjonction events at meiosis. Moreover, testicular ORIGINAL RESEARCH