Effects of vgll3 on maturation and its interaction with salinity in Atlantic salmon (Salmo salar, L)

Abstract

New emerging strategies in the production of Atlantic salmon (Salmo salar), for instance post-smolt and big smolt in land-based facilities experience maturation. High production rates, such as 24 hours photoperiods and high temperatures combined with full rations of feed, promote post-smolt maturation (“jacking”). The gene vgll3 regulate the weight at which maturation happens. Fish with the allele E (early) enter puberty earlier than fish with the allele L (late). As there are two alleles in each gene, we get the three genotypes EE, EL and LL. Eggs from three heterozygote mothers have been fertilised by a heterozygote male, producing three families all with theoretical 25% EE, 50% EL and 25% LL. The study finds that the allele E promotes maturation at a smaller size than the L allele, meaning EE fish mature first, then EL and lastly LL. Findings in this study reinforce the idea that EE fish mature earlier than EL, and EL fish mature earlier than LL. As salinity and maturation have been linked previously, this study finds that salinity does affect testis growth but does not affect jacking.