Vol. 9, Special Issue 7, Part J (2025)

Antimicrobial peptides (AMPs), especially β-defensins, serve as critical innate immune components in various organisms, including goats. The present study aimed to sequence and analyze the coding region of a β-defensin-1 like (GBD-1 Like) gene from the Osmanabadi goat, a breed known for its disease resistance. Tongue epithelial tissue from an Osmanabadi goat was collected aseptically, and total RNA was extracted. Complementary DNA (cDNA) synthesis was performed using standard protocols, and PCR amplification was conducted with primers specific to the GBD-1 Like gene. The PCR product of 275 bp was sequenced, and bioinformatic analysis was performed using DNASTAR and Phyre2 tools.

The open reading frame (ORF) comprised 195 nucleotides, encoding a 64-amino acid peptide. Sequence alignment at the nucleotide level showed up to 100% identity with other goat defensins and high similarity (89-99.6%) with defensins from other ruminants such as sheep, cattle, and buffalo. At the amino acid level, identity ranged from 71.9% to 100% with corresponding peptides from various species. Phylogenetic analysis confirmed that Osmanabadi GBD-1 Like clustered closely with goat defensins, forming a distinct group from those of other ruminants. Notably, an amino acid substitution (Valine replacing Leucine) was observed at position 13, which may affect the structural and functional properties of the peptide. Structural prediction using Phyre2 indicated this mutation's location and potential impact on peptide conformation. Further studies are warranted to explore the biological significance of this variation in immune response and disease resistance.