University of Guilan Animal Production Research 2252-0872 10 3 2021 11 22 Investigation of the relationship between exon 2 of MHC-DMB2 polymorphism and humoral immune response in Japanese quail Investigation of the relationship between exon 2 of MHC-DMB2 polymorphism and humoral immune response in Japanese quail 45 55 5238 10.22124/ar.2021.15822.1499 FA H. Chenani MSc Student of Animal Breeding and Genetics, Department of Animal Science, Faculty of Animal Science and Food Technology, Agricultural Science and Natural Resources University of Khuzestan, Mollasani, Iran M. Nazari Assistant Professor, Department of Animal Science, Faculty of Animal Science and Food Technology, Agricultural Science and Natural Resources University of Khuzestan, Mollasani, Iran M. T. Beigi Nassiri Professor, Department of Animal Science, Faculty of Animal Science and Food Technology, Agricultural Science and Natural Resources University of Khuzestan, Mollasani, Iran H. Roshanfekr Professor, Department of Animal Science, Faculty of Animal Science and Food Technology, Agricultural Science and Natural Resources University of Khuzestan, Mollasani, Iran A. Aghaei Assistant Professor, Department of Animal Science, Faculty of Animal Science and Food Technology, Agricultural Science and Natural Resources University of Khuzestan, Mollasani, Iran Journal Article 2020 03 03 The DMB2 gene is one of the MHC cluster genes that plays a role in the humoral immune response. This study was performed to identify the polymorphism of exon 2 of the MHC-DMB2 gene and its association with the humoral immune response in Japanese quail. For this purpose, on day 28, 0.2 mL of 5% saline suspension of sheep red blood cell (SRBC) was injected into 130 quail's breast muscle (65 males and 65 females). Seven days later, cervical vein blood sampling was performed on the 35^th day. Afterward, the anti-SRBC titer antibody was determined using a micro hemagglutination technique. Also, genomic DNA was extracted from blood samples and a 333bp fragment of exon 2 was amplified using polymerase chain reaction and PCR products were digested by Hinf 1 restriction enzyme. The results showed that there were two types of C (333bp) and G (226, 107bp) alleles in this region with a frequency of 74.6% and 26.4% in the whole population, respectively. The results indicate high polymorphism and high homozygosity in the studied population. In addition, the results showed that genotype had a significant effect on antibody titers (<em>P</em><0.01). The CC genotype showed the highest total antibody titer (2.13 mg/dL) and the GG genotype showed the lowest total antibody titer (0.33 mg/dL). It is suggested that the negative effects of this single nucleotide polymorphism be considered in breeding programs. The DMB2 gene is one of the MHC cluster genes that plays a role in the humoral immune response. This study was performed to identify the polymorphism of exon 2 of the MHC-DMB2 gene and its association with the humoral immune response in Japanese quail. For this purpose, on day 28, 0.2 mL of 5% saline suspension of sheep red blood cell (SRBC) was injected into 130 quail's breast muscle (65 males and 65 females). Seven days later, cervical vein blood sampling was performed on the 35^th day. Afterward, the anti-SRBC titer antibody was determined using a micro hemagglutination technique. Also, genomic DNA was extracted from blood samples and a 333bp fragment of exon 2 was amplified using polymerase chain reaction and PCR products were digested by Hinf 1 restriction enzyme. The results showed that there were two types of C (333bp) and G (226, 107bp) alleles in this region with a frequency of 74.6% and 26.4% in the whole population, respectively. The results indicate high polymorphism and high homozygosity in the studied population. In addition, the results showed that genotype had a significant effect on antibody titers (<em>P</em><0.01). The CC genotype showed the highest total antibody titer (2.13 mg/dL) and the GG genotype showed the lowest total antibody titer (0.33 mg/dL). It is suggested that the negative effects of this single nucleotide polymorphism be considered in breeding programs. https://ar.guilan.ac.ir/article_5238_a31882647e368e40283b30658460ce43.pdf