Analysis Of Tissue Different Expression Of TLRs,NLRs And AMPs Genes Between DPL And Landrace Pigs

In the swine production,diseases,especially infectious diseases have become a natural enemy of modern pig industry.The frequent use of drugs,vaccines and antibiotics has led to the emergence of problems such as drug resistance and serious drug residues,which cause a large number of economic losses.Therefore,it has been an urgent problem needed to be solved in current pig industry development that how to get rid of the occurrence of problems,such as drug resistance and serious drug residues,and improve the immunity and disease resistance of pigs.Previous studies have found that the disease resistance and immunity of Dapulian(DPL),a Chinese local pig species,are significantly higher than that of foreign Landrace.DPL pigs possessing this characteristic can be used as an excellent breed resource for disease resistance breeding,and provide good material for selecting of candidate genes in disease resistance breeding.However,disease resistance is related to the reaction capacity of the immune system.The pattern recognition receptors(PRRs)mainly functions via recognizing the pathogen-associated molecular patterns(PAMPs)in the innate immune responses and play an important role in the host defense against pathogenic microorganisms.Antimicrobial peptides(AMPs),as small peptide,are widely distributed in the animal body and have broad spectrum of antibacterial and antiviral properties.Therefore,we used the method of qRT-PCR and Western blot to detect the transcriptional expression of TLRs(TLR1–9),NLRs(NOD1,NOD2,CIITA,NLRC3 and NLRX1)and AMPs(pBD-1 and PR-39)genes in the selected tissues(heart,liver,spleen,lung,kidney,tonsil,mandibular lymph nodes and mesenteric lymph nodes)of DPL and Landrace pigs at different ages,and analyze the expression differences of these immune-related genes in order to find the differential expression genes related with immune in DPL and Landrace pigs,and provide theoretical basis for the disease resistance breeding of pigs and accelerate implement of the ultimate goal of disease resistance breeding.The results of this research are as follows:1.The analysis of expression differences of TLRs genes: the result of statistical analysis revealed that TLR mRNAs were all expressed ubiquitously in selected tissues of DPL and Landrace pigs.The expressions of TLR1 and TLR2 were the highest in mandibular lymphnodes,TLR3 in kidney,TLR4,TLR7,TLR8 and TLR9 in spleen,TLR5 and TLR6 in liver.Between two pig breeds,relative expression levels of most TLR genes of DPL pigs were significantly higher than Landrace pigs.Additionally,in the chronological order,most TLR genes expression increased with age in the two breeds.2.The analysis of expression differences of NLRs genes: The result of statistical analysis revealed that NLR mRNAs were all expressed generally in selected tissues of DPL and Landrace pigs.The expressions of NOD1,NOD2 and CIITA were the highest in spleen,NLRC3 in mandibular lymph nodes and NLRX1 in liver.The relative expression levels of NLR genes were significantly higher in all tested tissues in DPL than that in Landrace.On the other side,the expression level of most NLR genes were the most highest at age 4 months,and then declined.3.The analysis of expression differences of AMPs genes: The statistical results indicated that AMPs genes are all expressed in selected tissues of DPL and Landrace.The expression of pBD-1was the hightest in tonsil and PR39-1 in mesenteric lymph nodes.The expression of the two genes in all tissues of DPL were higher than Landrace.In the chronological order,the expression level of the two genes were highest at age 4 months and then declined.4.The detection of the expression of TLR4 and NOD2 protein in different organs and tissues: the results showed that both genes were expressed in various tissues and were consistent with the results of qRT-PCR.In conclusion,the expression levels of the three immune-related genes was significantly higher in DPL than that in Landrace,which was the important reseaon that the disease resistance and immunity of the DPL pigs were higher than Landrace.Additionally,the expression of these immune related genes are influenced by the breed,individual and its age,organs and tissues,which then lead to genetic differences of the disease resistance.