Comparison Of The Difference In Diploid And Triploid Female Rainbow Trout(Oncorhynchus Mykiss)muscles

The aim of this paper was to identify differences in the proximate composition,amino acid composition and expression of the muscle growth-related genes between diploid(2n)and triploid(3n)female rainbow trout(Oncorhynchus mykiss)that were reared under the same conditions.The research included three different body weight of diploid and triploid female rainbow trout.The main objectives of this study were to analyze and compare the differences in muscle growth between diploid and triploid female rainbow trout,to better characterize these fish for culture purposes and to establish a more profitable and sustainable triploid rainbow trout farming industry.Contribute to provide basic theory of biological evolution,histology,and genetic breeding in polyploid fish.This research were also provides reference value data for production application.The main results were as follows:(1)The lipid and protein contents of the triploid female rainbow trout were significantly higher(P<0.05)while their moisture content was lower than those of the diploid female rainbow trout.Glutamic acid had the highest content in both diploid and triploid female rainbow trout and the triploid female rainbow trout were higher than those of the diploid female rainbow trout.Total amino acid content were higher in triploid female rainbow trout(P<0.05).The delicious amino acids(Glu,Gly,Asp,Ala)in both diploid and triploid female rainbow trout were more than 35% of the total amino acids and the amino acid contents are higher than the FAO/WHO.With the increase of the body weight,the essential amino acid index(EAAI)was gradually reduce in both diploid and triploid female rainbow trout.The chemical score(CS)and amino acid score(AAS)were high in both diploid and triploid rainbow trout.(2)Diploid female rainbow trout muscle fiber diameter were significantly lower than the triploid(P<0.05)and the density were significantly higher than the triploid(P<0.05).With the increasing of body weight,the diameter of muscle fiber increased and the density of muscle fibre decreased gradually in both diploid and triploid female rainbow trout.Diploid female rainbow trout muscle was more tenderness than triploid.(3)Myo D1 m RNA expression was higher(P<0.05)while MSTN2 mRNA expression was lower(P<0.05)in triploid than in diploid female rainbow trout muscle.Both in muscle and liver,the expression of GHR and IGF-1 were higher in triploid rainbow trout than in diploid rainbow trout(P<0.05).In conclusion,triploid rainbow trout were found to exhibit significantly higher nutritional quality,better protein resources,larger muscle fiber area and greater growth potential than their diploid counterparts.The low expression of MSTN2,higher expression of Myo D1,GHR and IGF-1 is one of the reasons for the strong growth performance on triploid.