Genetic bottleneck in the threatened western population of European mink Mustela lutreola

The western population of European mink Mustela lutreola has recently suffe red a severe decline in over more than 50% of its range, probably disappear ing from Brittany in 1992 and from Pays de Loire in 1997. Allozyme electrop horesis on 38 presumptive loci showed that the proportion of polymorphic lo ci reached only 10.5% at P < 0.01 level in the European mink. Observed hete rozygosity averaged H-O = 0.02 and expected hererozygosity H-E = 0.038 but the F-IS index reached 0.48, revealing a considerable deficit. The low gene tic variability might be due to previous bottlenecks. Demographic depletion in Mustela lutreola resulted in a loss of genetic diversity emphasising th at reproductive exchanges were altered and worsening the risk of extinction of this vulnerable population.