Comparison of nucleotide and amino acids sequence of Nilgai (Boselaphus tragocamelus) interleukin-18 (IL-18) with other ruminants

Abstract

Interleukin-18, a component of innate immunity with potent interferon-ϒ-inducing activity, is not well characterized in wild ruminants. In this study, IL-18 cDNA of Nilgai (Boselaphus tragocamelus) was cloned and characterized. The nucleotide sequence was 582 bp long and contained its entire open reading frame encoding 193 amino acid residues. The sequence analysis indicated seven nucleotide substitutions with reported buffalo sequence showing 98.5% similarity, 97.8% with cattle and 97.6% with sheep. The Nilgai IL-18 cDNA included a putative cleavage site of IL-1β-converting enzyme (ICE) and IL-1 signature-like sequence identified in human and cat IL-18 cDNA. Both nucleotide as well as amino acid sequence similarity shows that the cloned sequence was closer to buffalo IL-18 sequence.