Genetic architecture of marine and freshwater maturation in Atlantic salmon
A key developmental transformation in the life of all vertebrates is the transition to sexual maturity, whereby individuals are capable of reproducing for the first time. In the farming of Atlantic salmon, unwanted maturation that occurs prior to harvest size has a serious negative impact as it retards growth while severely diminishing flesh quality.
Recent findings in European Atlantic salmon report the presence of a gene that exerts a large effect on age of maturation (VGLL3). We performed two genome wide association studies in Tasmanian animals, which are derived from North American stock, to map genetic loci that contribute to variation.
First, a total of 2721 fish with trait data describing maturation in the marine environment were genotyped using a custom SNP50 array. Second, genotypes were collected from 1846 fish with trait data describing maturation in freshwater. For both experiments, a case-control design lineage regression analysis was performed to identify associated regions. Neither GWAS suggests VGLL3 plays a major role in the two maturation traits as measured in the Tasmanian population. Further, the two traits have different architecture as few highly associated SNP were common to both experiments.
GWAS revealed a highly polygenetic nature for both maturation traits, with few common SNP suggesting they are likely controlled by largely distinct genetic mechanisms. Only two variants were significantly associated with both traits, and each display sex specific effects restricted to male fish. Neither GWAS suggest vgll3plays a major role as measured in the Tasmanian population. These results increase our understanding of the genetic basis of maturation and direct future strategies to delay maturation in this important aquaculture species.
Paper has been published as Mohamed et al 2019 Polygenic and sex specific architecture for two maturation traits in farmed Atlantic salmon. BMC Genomics https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-019-5525-4
Recent findings in European Atlantic salmon report the presence of a gene that exerts a large effect on age of maturation (VGLL3). We performed two genome wide association studies in Tasmanian animals, which are derived from North American stock, to map genetic loci that contribute to variation.
First, a total of 2721 fish with trait data describing maturation in the marine environment were genotyped using a custom SNP50 array. Second, genotypes were collected from 1846 fish with trait data describing maturation in freshwater. For both experiments, a case-control design lineage regression analysis was performed to identify associated regions. Neither GWAS suggests VGLL3 plays a major role in the two maturation traits as measured in the Tasmanian population. Further, the two traits have different architecture as few highly associated SNP were common to both experiments.
GWAS revealed a highly polygenetic nature for both maturation traits, with few common SNP suggesting they are likely controlled by largely distinct genetic mechanisms. Only two variants were significantly associated with both traits, and each display sex specific effects restricted to male fish. Neither GWAS suggest vgll3plays a major role as measured in the Tasmanian population. These results increase our understanding of the genetic basis of maturation and direct future strategies to delay maturation in this important aquaculture species.
Paper has been published as Mohamed et al 2019 Polygenic and sex specific architecture for two maturation traits in farmed Atlantic salmon. BMC Genomics https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-019-5525-4
