Population structure and divergence using microsatellite and gene locus markers in Chinook salmon (<i>Oncorhynchus tshawytscha</i>) populations

Heath, Daniel D.; Shrimpton, J. Mark; Hepburn, R. I.; Jamieson, S.; Brode, Sarah K.; Docker, Margaret F.

doi:10.1139/f06-044

Cited by 27 publications

(28 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, it is unlikely that pre-or post-settlement selection is causing the observed genetic patchiness among populations of Stegastes partitus in this study because neutral microsatellite markers are insensitive to natural selection, and it is unlikely that selection would occur across all 9 unlinked loci (Christie et al 2010). Our markers show no evidence of linkage with functional loci under selection as indicated by consistently low global F ST values across loci (our Table 1; Heath et al 2006). Furthermore, analysis using the Beaumont & Nichols (1996) algorithm showed no evidence of selection effects on these loci in either adult or juvenile populations.…”

Section: Discussionmentioning

confidence: 65%

Variability in connectivity indicated by chaotic genetic patchiness within and among populations of a marine fish

Hogan¹,

Thiessen²,

Heath³

2010

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

Despite substantial advances in our understanding of marine population dynamics, there is still much uncertainty as to what processes influence connectivity, gene flow and population structure. To explore this, we examined the spatial and temporal variation in population genetic structure of adult and recently settled bicolor damselfish Stegastes partitus, a coral reef fish. We genotyped adult and juvenile fish from 10 sites over 4 sample years at 9 microsatellite loci. We show spatial heterogeneity in adult and juvenile population structure; however, we found no evidence of a pattern of spatial genetic divergence. Furthermore, genetic structure changed through time and between life stages in an unpredictable manner. Using these data, we test whether pre-or postsettlement selection, sweepstakes effects or variability in connectivity can explain the observed chaotic genetic patchiness. Our results indicate that the contributions of various larval sources likely change through time as a result of stochastic processes such as oceanographic flow. Our results have implications for the management of marine populations, as spatial and temporal variability in connectivity may act to promote long term stability of populations. Therefore it is important that marine management efforts account for such heterogeneity in the design of protected areas.KEY WORDS: Connectivity · Temporal variability · Larval dispersal · Chaotic genetic patchiness · Genetic structure · Coral reef fish Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 417: [263][264][265][266][267][268][269][270][271][272][273][274][275] 2010 through time and space (Larson & Julian 1999). This fine-scale genetic heterogeneity, termed chaotic genetic patchiness (Johnson & Black 1982), is characterized by low level genetic differentiation among and between adult and recruit populations (i.e. low F ST ) that is not consistent in space or time (Johnson & Black 1984).There are 4 main hypotheses put forth to explain chaotic genetic patchiness (Larson & Julian 1999); each infers a different mechanism by which this pattern can be explained. These hypotheses are (1) localized postsettlement selection resulting from microgeographic variation in environmental conditions, (2) variable local natural selection on pre-settlement individuals generating variability in cohorts through space and time, (3) 'sweepstakes chance-matching' (Hedgecock 1994) created by variable reproductive success of the adult source populations as a result of stochastic processes. This causes a genetic drift effect during the larval stage and a subsequent reduction in genetic variability in the recruit populations, and (4) spatial and temporal variability in the genetic composition of recruits caused by fluctuations in the source of larvae (Selkoe et al. 2006).Post-settlement natural selection has been invoked to explain spatial genetic heterogeneity in a marine snail (Johannesson et al. 1995). Generally, however, most studies have shown that gen...

show abstract

Section: Discussionmentioning

confidence: 65%

Variability in connectivity indicated by chaotic genetic patchiness within and among populations of a marine fish

Hogan¹,

Thiessen²,

Heath³

2010

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

show abstract

“…For each microsatellite, forward and reverse primer sequences, PCR annealing temperatures (T m ), observed (H O ) and expected heterozygosity (H E ) and number of alleles found in the 16 parents from each population are indicated a Primer sequences published in Nelson and Beacham (1999), Williamson et al (2002), O'Connell et al (1997) b Touchdown PCR: Annealing temperature set at 64°C for initial cycle, then dropped by 1°C in each subsequent cycle until a final annealing temperature of 49°C was reached, which was continued through the remaining cycles polymerase chain reaction (PCR) following the protocol outlined in Heath et al (2006). Each forward primer was tagged with a fluorescent dye, which enabled the PCR products to be compared against size standards using the Li-Cor 4300 DNA analyzer (Li-Cor Biosciences, Lincoln, Nebraska).…”

Section: Microsatellite Parentage Analysismentioning

confidence: 99%

MHC-mediated local adaptation in reciprocally translocated Chinook salmon

2010

View full text Add to dashboard Cite

Most Pacific salmonid populations have faced significant population declines over the past 30 years. In order to effectively conserve and manage these populations, knowledge of the evolutionary adaptive state of individuals and the scale of adaptation across populations is needed. The vertebrate major histocompatibility complex (MHC) represents an important adaptation to parasites, and genes encoding for the MHC are widely held to be undergoing balancing selection. However, the generality of balancing selection across populations at MHC loci is not well documented. Using Chinook salmon (Oncorhynchus tshawytscha) from two populations, we follow the survival of full-sib family replicates reared in their natal river and reciprocally transplanted to a foreign river to examine selection and local adaptation at the MHC class I and II loci. In both populations, we found evidence of a survivorship advantage associated with nucleotide diversity at the MHC class I locus. In contrast, we found evidence that MHC class II diversity was disadvantageous in one population. There was no evidence that these effects occurred in translocated families, suggesting some degree of local adaptation at the MHC loci. Thus, our results implicate balancing selection at the MHC class I but potentially differing selection across populations at the class II locus.

show abstract

“…Thus, population genetic structure in broadcast spawning marine invertebrates likely results from a combination of selection and barriers to dispersal (Veliz et al 2006). The effects of selection and physical isolation can be partitioned by examining spatial genetic structure using neutral markers that are not under direct selective pressure and, hence, reflect primarily physical barriers to dispersal (Heath et al 2006).…”

Section: Introductionmentioning

confidence: 99%

Marine landscape shapes hybrid zone in a broadcast spawning bivalve: introgression and genetic structure in Canadian west coast Mytilus

Shields¹,

Heath²,

Heath³

2010

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

Adult marine mussels are sessile, but their highly dispersive planktonic larval stage plays a critical role in shaping population structure. However, shoreline geography and oceanographic currents can modify the dispersal pattern of pelagic larvae. On Vancouver Island (VI), British Columbia, 3 species of blue mussels (native Mytilus trossulus and introduced M. galloprovincialis and M. edulis) form a localized hybrid zone. Here we genetically mapped the distribution of Mytilus species and populations along VI and the surrounding islands. Using diagnostic species markers and microsatellite loci, we estimated the extent of the Mytilus hybrid zone on VI and measured population differentiation among the observed sites in 2005 and 2006. We predicted that the distribution of non-native genotypes would be mirrored by the microsatellite allelic patterns, which correspond to oceanographic features that reflect barriers to gene flow in the Strait of Georgia. Generally, non-native genotypes were restricted to southern VI and strong microsatellite population structure was detected. The distribution of non-native genotypes reflected patterns of microsatellite allele frequency in the Strait of Georgia. Using a landscape genetics approach, we identified 2 genetic discontinuities, which correspond to oceanographic and hydrographic features of the Strait of Georgia. Thus, physical dispersal barriers likely limit the spread of the VI Mytilus hybrid zone; however, additional biological barriers to dispersal must also exist. The VI Mytilus hybrid zone provides an excellent example of complex dispersal patterns in a non-equilibrium system.

show abstract

Population structure and divergence using microsatellite and gene locus markers in Chinook salmon (Oncorhynchus tshawytscha) populations

Cited by 27 publications

References 41 publications

Variability in connectivity indicated by chaotic genetic patchiness within and among populations of a marine fish

Variability in connectivity indicated by chaotic genetic patchiness within and among populations of a marine fish

MHC-mediated local adaptation in reciprocally translocated Chinook salmon

Marine landscape shapes hybrid zone in a broadcast spawning bivalve: introgression and genetic structure in Canadian west coast Mytilus

Contact Info

Product

Resources

About