Genetic polymorphism and expression analysis of cMBL gene in Iranian native and commercial chickens

The aims of this study were to compare the promoter sequence of the mannose-binding lectin (cMBL) gene in Iranian native and commercial chicken strains; as well as to compare the cMBL gene expression in crossbred and inbred chickens. In total 79 native (Western Azerbaijan native fowls, WANF) and 49 commercial (Arian Commercial Strain, ACS) birds were reared as parents under same management practices. Then, four genotypes of F1 offspring (purebreds: ACS and WANF, and crossbreds: ACS roosters × WANF hens and WANF roosters × ACS hens) were produced using artificial insemination. Sequence analysis of the promoter and exon 1 of the cMBL gene on the WANF and ACS parents was carried out; then, gene expression was analyzed in 4 genotypes of offspring. A valuable SNP (T>C) was found in −185 position of the cMBL promoter in the native birds. The mutation resulted in the modification of the promoter pattern to attachment of the c-Jun transcription factor. Due to the similarity of the c-Jun with the product of Avian Sarcoma Virus, it seems that the native birds are immunologically more resistant. Gene expression analysis revealed no significant differences between cMBL transcripts of 4 different genotypes; however, gene expression in crossbreds was slightly higher than in purebreds. The results showed that the promoter sequence of the cMBL gene in Iranian native and commercial birds is variable and is necessary to be investigated in further studies.