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 effec ts on their spatial and social organization. Our interest was focused on the relationships between genetic structure of populations, and the ir social structure and mating behaviour. A survey of allele frequenci es at seven coat-colour loci in rural and urban populations of domesti c cats in France confirmed the rural-urban dine for the Orange locus. The frequencies of the Orange allele were high in rural habitats, whic h were characterized by low densities (between 140 to 230 individuals per km(2)), and a polygynous mating system. Low frequencies of the Ora nge allele were found in urban populations, which had high densities ( 1300 cars per km(2)) and a promiscuous mating system. Orange males wer e heavier than non-Orange males, whereas Orange females were lighter t han non-Orange females. Due to the importance of body weight in life-h istory trails variability, we hypothesize that reproductive tactics ma y differ between individuals according to Orange genotype. This may ex plain why the Orange allele does not reach frequencies as high as thos e of non-agouti and blotched tabby alleles, which are more recent coat colour mutations.