GENETIC PROFILES FROM COAT GENES OF NATURAL BALEARIC CAT POPULATIONS - AN EASTERN MEDITERRANEAN AND NORTH-AFRICAN ORIGIN

A detailed study of 7 cat populations (Felis silvestris catus) in the 3 principal Balearic islands has been carried out. These populations a re Mahon (474 cats), Villacarlos (226 cats), Mercadal and Alayor (104 cats) and Ciudadela (510 cats) in Minorca, Palma Majorca (475 cats) in Majorca and Ibiza city (210 cats) and San Antonio (63 cats) in Ibiza. The gene frequencies derived from the phenotypic frequencies of a num ber of loci coding for coat colour and pattern, hair length and one sk eleton anomaly were studied with the following implied mutant allele: 0 (Orange; sex-linked allele); a (Non-agouti); t(b) (Blotched tabby); d (Dilution); 1 (Long hair); S (White spotting); W (Dominant white); c (s) (Siamese); and M (Manx). The range of frequency values for each of the loci studied is the following: O: 0.16-0.30; a: 0.72-0.87; t(b): 0.0-0.35; d: 0.14-0.44; 1: 0.0-0.27; S: 0.14-0.30; W: 0.0-0.017; c(s): 0.12-0.31; M: 0.0-0.026. In some populations in Minorca a significant excess of homozygotes was detected for the O locus which might be due to the influence of some evolutionary agent. Though the genetic heter ogeneity of the Balearic cat populations is substantially lower than t hat observed for other island mammals and the theoretical gene flow be tween these Balearic cat populations is noticeably stronger than that observed for other populations of mammals in these islands as well as in other islands, there is a statistically significant genetic heterog eneity between most of the loci studied and between the genetic profil es of the 7 cat populations. Some alleles (d, S, W and t(b)) even show a clinal disposition. An analysis of the contribution of each locus t o the gene diversity observed between the Iberian and Balearic cat pop ulations shows that the largest part of this diversity is due to the t (b) allele. Generally speaking, all the genetic profiles analyzed show stronger genetic influences of eastern Mediterranean and North-Africa n cat populations than of western European cat populations. However, o f the 7 cat populations studied, that of Palma shows a slightly strong er influence of western European cat populations while the central and eastern populations of Minorca (Mahon, Villacarlos and particularly M ercadal and Alayor) seem to have followed a characteristically differe nt evolutionary path caused by founder effect, gene drift and/or diffe rent gene flow from other places around the Mediterranean sea which ha ve not yet been thoroughly studied. The possible origin of other speci es of mammals and the historical and commercial movements of the human beings in these islands might be parallel to the model proposed for t he cat populations of the Balearic islands.