Mitochondrial DNA (mtDNA) plays a pivotal role in cellular bioenergetics, immune regulation, and evolutionary adaptation, making it a uniquely informative genomic system for studying host–pathogen interactions. The cytochrome b (cyt b) gene, one of the most conserved mitochondrial protein-coding loci, is widely recognized for its utility in species identification, phylogenetics, and molecular evolution [1-3]. However, its potential role in shaping comparative host susceptibility to infectious diseases remains underexplored. In this study, we re-analyzed PCR–RFLP-derived mitochondrial cyt b restriction profiles targeting CCNNGG, GTAC, AGCT, TTAA, and CGCG motifs across seven vertebrate hosts: cattle, buffalo, pig, goat, rabbit, chicken, and quail. These motif architectures were compared with documented susceptibility patterns for Pasteurellosis, foot-and-mouth disease (FMD), Rinderpest, and Sarcoptes scabiei infestation [4, 6, 7]. The integrated motif matrix revealed distinct host-specific restriction profiles and four comparative genomic vulnerability clades. The findings support a model in which conserved mitochondrial motif architecture may reflect evolutionary genomic signatures relevant to pathogen–host range and susceptibility. The study is intended as a comparative genomic framework and does not claim direct causality between single restriction motifs and disease outcome.
