Evolution and determination of phenotype in salmonid fishes: Inferences from molecular markers in the absence of pedigree

Molecular markers can be used to scrutinize both pedigree and population genetic structure, providing important insights into phenotypic evolution and determination in natural populations. Here, microsatellite markers were used to investigate the determination of size, growth, and maturation traits...

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Main Author: Wilson, Alastair James
Other Authors: Ferguson, M.M.
Format: Thesis
Language:English
Published: University of Guelph 2002
Subjects:
Online Access:https://hdl.handle.net/10214/24869
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spelling ftunivguelph:oai:atrium.lib.uoguelph.ca:10214/24869 2023-11-05T03:43:34+01:00 Evolution and determination of phenotype in salmonid fishes: Inferences from molecular markers in the absence of pedigree Wilson, Alastair James Ferguson, M.M. 2002 application/pdf https://hdl.handle.net/10214/24869 en eng University of Guelph https://hdl.handle.net/10214/24869 All items in the Atrium are protected by copyright with all rights reserved unless otherwise indicated. microsatellite markers determination pedigree population genetic structure phenotypic evolution size growth maturation traits salmonid fishes Thesis 2002 ftunivguelph 2023-10-08T06:13:35Z Molecular markers can be used to scrutinize both pedigree and population genetic structure, providing important insights into phenotypic evolution and determination in natural populations. Here, microsatellite markers were used to investigate the determination of size, growth, and maturation traits in salmonid fishes. Two marker-assisted methodologies for estimating quantitative genetic parameters were compared in an aquaculture population of rainbow trout ('Oncorhynchus mykiss'). A regression-based model employing estimates of pairwise relatedness effectively detected significant components of genetic variance and covariance for size and spawning time traits. However, numerical estimates of parameters were unreliable. A Markov Chain Monte Carlo (MCMC) procedure to reconstruct families resulted in estimates that did not differ significantly from those obtained with known pedigree, and was therefore deemed the superior method. This method was then used to investigate constraints on the evolution of larger body size in two stunted populations (designated Lower and Upper) of brook charr ('Salvelinus fontinalis') from Freshwater River, Cape Race, Newfoundland, Canada. Population structure of the system was investigated using ecological and genetic methods. Over a 5-year period, mark-recapture data revealed limited movement, with the proportion of recaptured fish migrating from one population area to another being low (0-3.8%). Despite this, microsatellite analysis based on sixteen polymorphic loci provided no evidence of genetic differentiation. These results indicate that while gene flow occurs between the populations, they are relatively isolated on an ecological time frame. Selective and genetic constraints on the evolution of larger body size were investigated by measuring viability selection acting on length-at-age traits, and by estimating quantitative genetic parameters 'in situ' (following reconstruction of sibships using the MCMC procedure). In the Lower population, significant heritabilities were found for ... Thesis Newfoundland University of Guelph: DSpace digital archive
institution Open Polar
collection University of Guelph: DSpace digital archive
op_collection_id ftunivguelph
language English
topic microsatellite markers
determination
pedigree
population genetic structure
phenotypic evolution
size
growth
maturation traits
salmonid fishes
spellingShingle microsatellite markers
determination
pedigree
population genetic structure
phenotypic evolution
size
growth
maturation traits
salmonid fishes
Wilson, Alastair James
Evolution and determination of phenotype in salmonid fishes: Inferences from molecular markers in the absence of pedigree
topic_facet microsatellite markers
determination
pedigree
population genetic structure
phenotypic evolution
size
growth
maturation traits
salmonid fishes
description Molecular markers can be used to scrutinize both pedigree and population genetic structure, providing important insights into phenotypic evolution and determination in natural populations. Here, microsatellite markers were used to investigate the determination of size, growth, and maturation traits in salmonid fishes. Two marker-assisted methodologies for estimating quantitative genetic parameters were compared in an aquaculture population of rainbow trout ('Oncorhynchus mykiss'). A regression-based model employing estimates of pairwise relatedness effectively detected significant components of genetic variance and covariance for size and spawning time traits. However, numerical estimates of parameters were unreliable. A Markov Chain Monte Carlo (MCMC) procedure to reconstruct families resulted in estimates that did not differ significantly from those obtained with known pedigree, and was therefore deemed the superior method. This method was then used to investigate constraints on the evolution of larger body size in two stunted populations (designated Lower and Upper) of brook charr ('Salvelinus fontinalis') from Freshwater River, Cape Race, Newfoundland, Canada. Population structure of the system was investigated using ecological and genetic methods. Over a 5-year period, mark-recapture data revealed limited movement, with the proportion of recaptured fish migrating from one population area to another being low (0-3.8%). Despite this, microsatellite analysis based on sixteen polymorphic loci provided no evidence of genetic differentiation. These results indicate that while gene flow occurs between the populations, they are relatively isolated on an ecological time frame. Selective and genetic constraints on the evolution of larger body size were investigated by measuring viability selection acting on length-at-age traits, and by estimating quantitative genetic parameters 'in situ' (following reconstruction of sibships using the MCMC procedure). In the Lower population, significant heritabilities were found for ...
author2 Ferguson, M.M.
format Thesis
author Wilson, Alastair James
author_facet Wilson, Alastair James
author_sort Wilson, Alastair James
title Evolution and determination of phenotype in salmonid fishes: Inferences from molecular markers in the absence of pedigree
title_short Evolution and determination of phenotype in salmonid fishes: Inferences from molecular markers in the absence of pedigree
title_full Evolution and determination of phenotype in salmonid fishes: Inferences from molecular markers in the absence of pedigree
title_fullStr Evolution and determination of phenotype in salmonid fishes: Inferences from molecular markers in the absence of pedigree
title_full_unstemmed Evolution and determination of phenotype in salmonid fishes: Inferences from molecular markers in the absence of pedigree
title_sort evolution and determination of phenotype in salmonid fishes: inferences from molecular markers in the absence of pedigree
publisher University of Guelph
publishDate 2002
url https://hdl.handle.net/10214/24869
genre Newfoundland
genre_facet Newfoundland
op_relation https://hdl.handle.net/10214/24869
op_rights All items in the Atrium are protected by copyright with all rights reserved unless otherwise indicated.
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