Microsatellite variation in grey seals (Halichoerus grypus) shows evidence of genetic differentiation between two British breeding colonies

Abstract

Eight highly variable microsatellite loci were used to examine the genetic variability and differentiation of grey seals (Halichoerus grypus) at two widely spaced British breeding colonies. Samples were collected from adults and pups on the island of North Rona, off the north-west coast of Scotland, and on the Isle of May, situated at the mouth of the Firth of Forth on the east coast. Highly significant differences in allele frequencies between these two sites were found for all eight loci, indicating considerable genetic differentiation. Thus, although grey seals are known to range over very large areas outside the breeding season, site fidelity of adults and philopatry of pups for these breeding colonies must be sufficiently common to have effects, through genetic drift, at the sub-population level. Migration rate was estimated using Wright's fixation index (FST), Slatkin's private alleles model and the new statistic, RST, which is analogous to FST but which takes into account the process of microsatellite mutation. An almost 8-fold discrepancy between the values we obtained provides cautionary evidence that microsatellite loci may contravene one or more of the assumptions on which these methods are based.

Microsatellite assessment of walrus (<i>Odobenus rosmarus rosmarus</i>) stocks in Canada

“…The extracted DNA was diluted to 10 ng/μl. Eight microsatellite loci from walruses (Buchanan et al 1998) and three from grey seals (Halichoerus grypus; Allen et al 1995) were amplified in three duplex and five single PCR reactions: 1) Orr3 + Orr11 2) Orr24 3) Orr7 + Orr23 4) Orr9 + Orr16 5) SGPV9 6) Hg3.6 7) Hg6.1 and 8) HgDii. The 15 μl PCR reactions contained double-distilled water, 1.5X PCR buffer, 0.24 μM of each primer, and 0.24 mM of each dNTP.…”

Proximate factors associated with high levels of extraconsort fertilization in polygynous grey seals

“…Isolated DNA was diluted to 50 ng/jil for the polymerase chain reaction (PCR) amplification of microsatellites. We amplified seven hypervariable microsatellites developed for eastern Atlantic grey seals and harbour seals, Phoca vitulina (Allen et al 1995) for the paternity analysis. We conducted preliminary analysis using these six microsatellites on 50 grey seal males at the Molecular Genetics Laboratory at Cambridge University following the protocol of Allen et al (1995).…”

“…We amplified seven hypervariable microsatellites developed for eastern Atlantic grey seals and harbour seals, Phoca vitulina (Allen et al 1995) for the paternity analysis. We conducted preliminary analysis using these six microsatellites on 50 grey seal males at the Molecular Genetics Laboratory at Cambridge University following the protocol of Allen et al (1995). We analysed the remainder of the samples at the Molecular Genetics Laboratory at National Zoological Park, Smithsonian Institution, adding an additional micro satellite locus to all seals.…”

Genomic signatures of population bottleneck and recovery in Northwest Atlantic pinnipeds

“…In comparison with the relatively rich history of regional genetic studies of gray seals (Allen, Amos, Pomeroy, & Twiss, 1995; Cammen, Hoffman, Knapp, Harwood, & Amos, 2011; Gaggiotti et al., 2002) and to a slightly lesser extent harbor seals (Goodman, 1998; Olsen et al., 2017) in the Northeast Atlantic, there exists relatively little parallel analysis of gray or harbor seals in the Northwest Atlantic, and few attempts to model or monitor long‐ or short‐term histories using genetic tools. Samples from this region have been occasionally incorporated into worldwide or ocean basin analyses (Cammen et al., 2011; Klimova et al., 2014; Stanley et al., 1996), but within the Northwest Atlantic, most seal genetics studies have focused on a single colony (Coltman, Bowen, & Wright, 1998; Worthington Wilmer, Allen, Pomeroy, Twiss, & Amos, 1999).…”