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Allelic variation of Mhc class II in Atlantic salmon; a population genetic analysis

Langefors, Åsa LU ; von Schantz, Torbjörn LU and Widegren, B. (1998) In Heredity 80(5). p.568-575
Abstract
We have studied the degree of genetic variation at a variable Mhc class II beta gene in four populations of Atlantic salmon Salmo salar by using RFLPs. The class II beta gene encodes the part of the Mhc class II molecule that contains the antigen binding region and is therefore essential for disease resistance. There was extensive genetic variation in all four populations; the expected heterozygosity (H-si) varied between 0.50 and 0.81. Heterozygosity tended to be higher in broods surviving a syndrome causing high mortalities (60-95%) in Swedish salmon hatcheries. Populations that had experienced more incidences of genetic bottlenecks (years when fewer than 60 adults had been used for breeding) and had a lower average effective population... (More)
We have studied the degree of genetic variation at a variable Mhc class II beta gene in four populations of Atlantic salmon Salmo salar by using RFLPs. The class II beta gene encodes the part of the Mhc class II molecule that contains the antigen binding region and is therefore essential for disease resistance. There was extensive genetic variation in all four populations; the expected heterozygosity (H-si) varied between 0.50 and 0.81. Heterozygosity tended to be higher in broods surviving a syndrome causing high mortalities (60-95%) in Swedish salmon hatcheries. Populations that had experienced more incidences of genetic bottlenecks (years when fewer than 60 adults had been used for breeding) and had a lower average effective population size (N-e), had a lower degree of heterozygosity. The four populations differed significantly in allele frequencies as measured by F-ST = 0.13 and Nei's genetic distance (D = 0.09 - infinity). Pairwise F-ST values varied between 0.01 and 0.23, all but one being highly significant, indicating a differentiation between the populations in Mhc class II beta. This study shows that the four populations of Atlantic salmon have a high degree of polymorphism in the Mhc class II beta gene. However, there was great variation between different hatcheries, both in heterozygosity levels and allele frequencies. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
allele frequency, Atlantic salmon, genetic variation, heterozygosity, Mhc, population, major histocompatibility complex, electrophoretic variation, f-statistics, diversity, trout, polymorphism, variability, selection, pacific, salar
in
Heredity
volume
80
issue
5
pages
568 - 575
publisher
Macmillan
external identifiers
  • scopus:0031831592
ISSN
1365-2540
DOI
10.1046/j.1365-2540.1998.00321.x
language
English
LU publication?
yes
id
3d257847-6374-47c7-bfc5-e02abd51cd33 (old id 1747672)
date added to LUP
2011-05-11 12:45:11
date last changed
2017-01-01 04:31:11
@article{3d257847-6374-47c7-bfc5-e02abd51cd33,
  abstract     = {We have studied the degree of genetic variation at a variable Mhc class II beta gene in four populations of Atlantic salmon Salmo salar by using RFLPs. The class II beta gene encodes the part of the Mhc class II molecule that contains the antigen binding region and is therefore essential for disease resistance. There was extensive genetic variation in all four populations; the expected heterozygosity (H-si) varied between 0.50 and 0.81. Heterozygosity tended to be higher in broods surviving a syndrome causing high mortalities (60-95%) in Swedish salmon hatcheries. Populations that had experienced more incidences of genetic bottlenecks (years when fewer than 60 adults had been used for breeding) and had a lower average effective population size (N-e), had a lower degree of heterozygosity. The four populations differed significantly in allele frequencies as measured by F-ST = 0.13 and Nei's genetic distance (D = 0.09 - infinity). Pairwise F-ST values varied between 0.01 and 0.23, all but one being highly significant, indicating a differentiation between the populations in Mhc class II beta. This study shows that the four populations of Atlantic salmon have a high degree of polymorphism in the Mhc class II beta gene. However, there was great variation between different hatcheries, both in heterozygosity levels and allele frequencies.},
  author       = {Langefors, Åsa and von Schantz, Torbjörn and Widegren, B.},
  issn         = {1365-2540},
  keyword      = {allele frequency,Atlantic salmon,genetic variation,heterozygosity,Mhc,population,major histocompatibility complex,electrophoretic variation,f-statistics,diversity,trout,polymorphism,variability,selection,pacific,salar},
  language     = {eng},
  number       = {5},
  pages        = {568--575},
  publisher    = {Macmillan},
  series       = {Heredity},
  title        = {Allelic variation of Mhc class II in Atlantic salmon; a population genetic analysis},
  url          = {http://dx.doi.org/10.1046/j.1365-2540.1998.00321.x},
  volume       = {80},
  year         = {1998},
}