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The article examines the immune traits of different chicken breeds in China. Researchers assessed 80 chickens form Rugao Chicken (RG), Wenchang Chicken (WC) and Anka Chicken (CK) and injected 0.5 milliliters (mL) of suspension of red blood cell (SRBC). They found that the value of heterophil/lymphocytes (H/L) varies according to age, wherein H/L in RG is lesser compared to other breeds. They concluded that the immune traits of chickens vary according to breeds.

Previous research has revealed that miR-215 might be an important miRNA regulating weaned piglets' resistance to Escherichia coli ( E. coli) F18. In this study, target genes of miR-215 were identified by RNA-seq, bioinformatics analysis and dual luciferase detection. The relationship between target genes and E. coli infection was explored by RNAi technology, combined with E. coli stimulation and enzyme linked immunosorbent assay (ELISA) detection. Molecular regulating mechanisms of target genes expression were analyzed by methylation detection of promoter regions and dual luciferase activity assay of single nucleotide polymorphisms (SNPs) in core promoter regions. The results showed that miR-215 could target EREG , NIPAL1 and PTPRU genes. Expression levels of three genes in porcine intestinal epithelial cells (IPEC-J2) in the RNAi group were significantly lower than those in the negative control pGMLV vector (pGMLV-NC) group after E. coli F18 stimulation, while cytokines levels of TNF-α and IL-1β in the RNAi group were significantly higher than in the pGMLV-NC group. Variant sites in the promoter region of three genes could affect their promoter activities. These results suggested that miR-215 could regulate weaned piglets' resistance to E. coli F18 by targeting EREG , NIPAL1 and PTPRU genes. This study is the first to annotate new biological functions of EREG , NIPAL1 and PTPRU genes in pigs, and provides a new experimental basis and reference for the research of piglets disease-resistance breeding.

Enterotoxigenic Escherichia coli F18 (ETEC F18) is the main pathogen that causes edema disease and post-weaning diarrhea in piglets, and a1-fucosytransferase (FUT1) gene has been identified as a receptor gene encoding the receptor for ETEC F18 bacteria. In this study, the method of PCR-RFLP was used to investigate the among 21 breeds including one wild boar breed and 20 western commercial and Chinese native pig breeds (populations). The results showed that none of the individuals in all 21 breeds possessed the resistant AA genotype, the genetic polymorphisms of the FUT1 locus were only detected in two western pig breeds (Duroc and Yorkshire), Lingao pig and hybrid pig breeds, while the wild boar and all the other Chinese pig breeds only possessed the susceptible GG genotype. The results indicated that Chinese native pig breeds, unlike western pig breeds, lack the genetic background on the resistance to ETEC F18 bacteria. This may be owe to their different origination, as the resistance gene to ETEC F18 might be originated from European wild boar. It was also inferred that edema disease and post-weaning diarrhea caused by ETEC F18 had close relationship with the growth speed of pigs.

By the PCR-RFLP method, the polymorphisms of exon 14 of Mx1 gene were detected in 7 native and foreign pig breeds. Taken together with the analysis of restriction enzyme Hin6 I digestion, there were 6 genotypes and 3 alleles. And, all individuals of Duroc exhibited the AA genotype but the Sutai pigs exhibited all three kinds of genotypes. The BB genotype was detected only in Meishan pigs and their derivate Sutai pigs. Among all pig breeds, the allele B only appeared in Chinese indigenous pig breeds and developed pig breed in this study, and the allele A was dominant allele in all pig breeds except for Songliao black pig. The results of Chi Square test showed that there were abundant polymorphisms in all pig breeds. The gene frequency of Meishan pig and Songliao black pig showed greatly significant difference to other pig breeds (P<0.01), Sutai pig showed greatly significant difference (P<0.01) to other pig breeds except for Pietrain; and Huai pig showed greatly significant differences (P<0.01) with Pietrain and other indigenous Chinese pig breeds, but no difference with Duroc and Yorkshire (P>0.05). Three new mutation points in three genotypes were identified by sequencing comparison analysis of PCR products, two of which resulted in Thr-->Ala and Glu-->Arg respectively, the last one was a silence mutation, the Glu-->Arg mutation point and this silence mutation point only appeared in the individuals with the BB genotype.

The single nucleotide polymorphism (SNP) of growth hormone gene was investigated in various breeds of duck, including Beijing ducks, Xihu mallards, Jinding ducks, Shan Partridge ducks, Jingjiang ducks and Shaoxing ducks. The primers for intron 2 and 3 in GH gene were designed based on the database of duck genomic sequence and the SNPs were detected by PCR-SSCP method. Eight SNPs were found among individuals within a breed, which were 2593(C-T), 2770(G-A), 2813(T-A), 2829(C-A), 2894(C-T), 2896(T-C), and 3100(C-G) in intron 2 and 3270(A-G) in intron 3. The analytic results showed that the frequencies of genotypes in different breeds were significantly different. Based on these SNPs, Beijing ducks and Shaoxing ducks represented their own unique conservativeness, indicating that these SNPs may have relationship with some productive traits of duck.

This study investigates single nucleotide polymorphism (SNP) of the adenylosuccinate lyase(ADSL) gene in variety chicken breeds, including Recessive White chickens, Silkies chickens, Baier chickens, Tibetan chickens and two red jungle fowls. Primers for exon 2 in ADSL gene were designed based on the chicken genomic sequence and a SNP(C/T at 3484) was detected by PCR-SSCP and DNA sequencing. Three genotypes within all breeds were found and least square analysis showed that TT genotype birds had a significant higher inosine monophosphate acid (IMP) content than TC (P < 0.01) and CC (P < 0.05) genotype birds, TC genotype birds had a little higher IMP content than CC genotype birds, but the difference was not significant. We proposed this SNP site correlated with IMP content in chickens. A neighbour-joining dendrogram was constructed based on the Nei's genentic distance. The genetic relationship between Chinese red jungle fowl and Tibetan chickens was the nearest, whereas Baier chickens were more closer to Silkies chickens. The Chinese red jungle fowls were relatively closer to the domestic fowls, whereas Thailand red jungle fowls were relatively diverging to the Chinese native breeds. These results supported the theory concerning the independent origins of Chinese native fowl breeds.