Comparative Study On The Different Content Of Protein In Feed Of The Growth And Immune Effect Of Different Local Populations Of Macrobrachium.nipponensis

In this paper,we used casein to regulate the protein content of feed and set up 4 test feed with different levels of protein level of 30%,36%,42%and 48%,and then biochemistry and molecular biological was used to research the Macrobrachium nipponense of Dianshan Lake to research the nutrition of different protein levels on the growth performance,immune function,resistance to nitrite.We also cloned the gene which related molting and growth—chitin deacetylase 1?CDA1?and phagocytic immune related protein—phagocytic cell protein?PAP?,and analyzed the expression level in different nutritional conditions under the different tissues.It also explores the differences between genetic analysis in different regions and different populations of M.nipponense growth and immunity performance in protein in different nutritional conditions and population.The main results of this paper are as follows.1.The optimal protein level in the diet of Oriental river prawn wasinvestigated.4 isocaloric diets containing 30%?36%?42%and 48%crude protein?casein?were tested.Prawns fed 42%or 48%protein exhibited higher weight gain,specific growth rate,hepatopancreas somatic indices,feed coefficient,and survival rate.Trypsin activity in the hepatopancreas increased with increasing dietary protein,with no significant difference between 42%and 48%groups?P<0.05?.Amylase,lipase,and cellulase levels were comparable between groups?P>0.05?.Crude protein content in muscle increased with increasing dietary protein,with no significant difference between 42%and 48%diets?P>0.05?.There were no significant differences in moisture,crude fat,or crude ash between groups.Essential amino acids lysine,tryptophan,phenylalanine,threonine,isoleucine,leucine,and valine increased with increasing dietary protein,with no significant difference between 42%and 48%groups?P>0.05?.Total and essential amino acids increased with increasing dietary protein.Cloning of the full-length 2435 bp M.nipponense chitin deacetylase 1?MnCDA1?gene have an open reading frame of 1632 bp encoding a 535 residue polypeptide,qPCR revealed highest expression in the hepatopancreas,followed by muscle,gill?heart?and eyestalk.Expression in hepatopancreas and gill tissue,but not muscle,increased gradually with increasing dietary protein.2.The aim of the present study was to determine the effects of dietary protein levels on resistance to Aeromonas hydrophila infection,immunity-and antioxidant-related enzyme activity,and expression of the PAP gene in M.nipponense.This is also the first study to clone and sequence the PAP gene in M.nipponense.Four isocaloric diets containing30%,36%,42%and 48%crude protein?casein?were used.After A.hydrophila infection,the survival rate and superoxide dismutase,catalase,acid phosphatase and lysozyme activity were found to increase with increase in the dietary protein content,with the 48%protein group having significantly higher values than the other groups.The full-length 494-bp PAP gene of M.nipponense was found to contain an open reading frame of 363 bp that encodes 120 amino acids.The molecular weight of the protein was predicted to be 13.5 kDa,and the theoretical PI was 11.04.The results of RT-PCR showed that PAP was distributed in the hepatopancreas?muscle?gill?heart and eyestalk,that the highest expression was in the hepatopancreas.PAP expression in the hepatopancreas and gill tissue increased gradually with increase in the protein content.After A.hydrophila infection,PAP expression in the hepatopancreas increased till it reached a peak at 10 h,reached its peak then decreased,the expression level was stable.after 24h,the expression of96h was almost unchanged after 24h,the present results indicate that a high protein diet can improve immune function in M.nipponense,and that the PAP gene may play a role in the innate immune system of this prawn species.3.With the development of our society,a large amount of industrial and domestic sewage discharge has become an important cause of water pollution.The nitrite is one of the most common toxic pollutants in large-scale aquaculture,the current research is focused on m.nipponense protein requirement,as well as the protein source instead.For the m.nipponense anti nitrite stress at different protein level has not been reported.The median lethal concentration Challenge with Lc50 13.3mg/L sodium nitrite to study the effects of dietary protein levels on M.nipponense nitrite stress resistance.The results showed that the activity of Na⁺K⁺ATPase and Ca²⁺Mg²⁺ATPase of gill was gradually increased with the increase of protein content,the alkaline phosphatase?ACP?and lysozyme?LSZ?was also increased with the increase of protein content,Using transmission electron microscope to observe the hepatopancreas of M.nipponense in nitrite stress,the hepatopancreas was seriously damage but with the increase of protein content,the injury was slowed down.4.In order to study the different nutritional conditions on the growth performance and immunity of Dianshan Lake?DS?,Dongting Lake?DT?,and their hybridization?DSxDT?we set the protein level of 3different nurtrion test 30%?36%?42%,after 8 weeks feeding trial determinted the growth profermance and immunity,and then calculation and statistics of the average observed number of alleles,the average effective number of alleles,heterozygosity,polymorphism information content Hardy-Weinberg balance deviation index,the coefficient of genetic similarity data by microsatellite loci of 11 high polymorphism of M.nipponense the.The results showed that the weight gain rate and specific growth rate of DTDS was higher than those of the parents under all raising conditions,and the feed coefficient hybrids were lower than those of the parents.The activity of protease and amylase,in 42%group was significantly higher than others,but there is no significant differences in between the 30%and 36%group alkaline phosphatase,the acid phosphatase,lysozyme,and increased with the increase of protein content in the feed,there is no significant difference between the three groups in the same protein content.The results of microsatellite analysis of 3 groups of m.nipponense populations showed high levels of genetic diversity,the average expected heterozygosity was 0.733,showed high levels of genetic diversity.The Fst value is 0.00954⁰.3171.it is also found that Mn10,Mn12,Mn33 and Mn39 realated to body length and body weight,The aa genotype of the Mn10 locus is negatively correlated with body weight length,bb was positively correlated with the weight,aa genotype of Mn12is negatively related to body weight therefore,and negative correlation between ab genotypes of Mn12 and body length.The ee genotype of the Mn33 locus is negatively correlated with body weight,and the bb genotype of the Mn39 locus is negatively correlated with body weight length.Thereforegrowth related genes of M.nipponense may be located near the site.through further analysis of gene sequences of these sites nearby might be obtain functional genes related to the growth of M.nipponense...