EVIDENCE OF SELECTION ON THE ORANGE ALLELE IN THE DOMESTIC CAT FELIS-CATUS - THE ROLE OF SOCIAL-STRUCTURE

Various ecological conditions encountered by cats have important effects on their spatial and social organization. Our interest was focused on the relationships between genetic structure of populations, and their social structure and mating behaviour. A survey of allele frequencies at seven coat-colour loci in rural and urban populations of domestic cats in France confirmed the rural-urban dine for the Orange locus. The frequencies of the Orange allele were high in rural habitats, which were characterized by low densities (between 140 to 230 individuals per km(2)), and a polygynous mating system. Low frequencies of the Orange allele were found in urban populations, which had high densities (1300 cars per km(2)) and a promiscuous mating system. Orange males were heavier than non-Orange males, whereas Orange females were lighter than non-Orange females. Due to the importance of body weight in life-history trails variability, we hypothesize that reproductive tactics may differ between individuals according to Orange genotype. This may explain why the Orange allele does not reach frequencies as high as those of non-agouti and blotched tabby alleles, which are more recent coat colour mutations.