Abstract

In almost all animal species, natural resistance-associated macrophage proteins (NRAMPs) have been linked to disease resistance. It plays a crucial part in innate immunity and can affect adaptive immunity as well. The aim of this study was to investigate some immunological traits and molecular genetics in the native breed of chickens, named Sinai (S) and a commercial strain of Lohman Brown (LB). The NRAMP1 gene was reported to be associated with a defense mechanism against infection by bacteria and viruses. A total of 144 female day-old chicks, including 72 from the commercial layer strain (LB) and 72 from the Egyptian native chicken strain (S), were used in this study. At 38 days of age, blood samples were taken randomly from 8 chickens of each group for serum antibodies against the New Castle disease virus, avian influenza virus, and infectious bursal disease virus analysis. Additionally, genomic DNA was extracted from 20 blood samples at 38 days of age. Polymerase chain reaction (PCR) analyses were conducted on the DNA samples, followed by sequencing of the PCR products to identify single nucleotide polymorphisms (SNPs) in the NRAMP1 gene in the two strains of chickens. The findings indicated that lymphocyte, eosinophil, phagocyte activity, and IgY were significantly greater in LB chicks than in S chicks. Sinai chickens, on the other hand, achieved dominance in Newcastle titter. Eight SNPs were found in NRAMP1 of the two strains. The nucleotide identity between S and LB nucleotides was 58.68%, while the changes in different amino acids were found in different positions. Multiple SNPs in the NRAMP1 gene have been discovered in Sinai and LB, suggesting that this gene can be used as a genetic marker for the selection of high-producing indigenous hybrids with the ability to resist pathogenic diseases in poultry.