Genetic variation in the hooded seal, Cystophora cristata, based on enzyme polymorphism and multi-locus DNA fingerprinting.

ABSTRACT

The genetic population structure of hooded seal, Cystophora cristata, was examined by electrophoretic analysis of allozymes and with multilocus DNA fingerprinting. Samples were collected in the Jan Mayen area and off Newfoundland. Allele products were resolved by isoelectric focusing. Only five of 32 protein-coding loci investigated were polymorphic at the 95% level. The proportion of polymorphic loci was estimated to P = 0.233, and average heterozygosity to H = 0.047. Tissue distribution, genotype distribution, and approximate pI (4 degrees C) of the proteins are reported. The allele frequencies of the AAT-2, GPD-2, and GPI-1 loci, were used in genetic comparisons of samples from the two stocks. Chi-square and G-tests showed no significant difference among the samples from the two groups. Highly variable profiles of HaeIII, HinfI and MboI digested genomic DNA were revealed using the human minisatellites 33.15 and 33.6 (HinfI digests only) as hybridization probes. Comparisons of band-sharing coefficients from HinfI and MboI digest were carried out. We were unable to detect significant differences in band-sharing between Newfoundland and the Jan Mayen area. The hypothesis that there is a considerable degree of intermixing between the stocks cannot be rejected.