The Nexus of Extreme Longevity and Physiological Stress: An Evolutionary Rationale for Heightened CIRBP-Mediated DNA Repair in the Bowhead Whale (\textit{Balaena mysticetus})

The bowhead whale (\textit{Balaena mysticetus}) exhibits a lifespan exceeding 200 years. It shows resistance to age-related diseases, including cancer. Studies indicate that cold-inducible RNA-binding protein (CIRBP) is expressed at high levels in this species. CIRBP enhances DNA double-strand break (DSB) repair. This contributes to genomic stability and longevity \citep{firsanov2024dna}. This conceptual framework posits that the whale's physiological adaptations drive the evolution of elevated CIRBP expression. These adaptations include bradycardia and cellular hypoxia during deep dives. Recurrent dive-induced stress involves low temperatures and oxygen deprivation. This poses a risk of DNA damage. This selective pressure likely favored increased CIRBP activity as an adaptive response. CIRBP's role in DSB repair aligns with this model. It mitigates genotoxic effects of the whale's metabolic and circulatory physiology. This supports its longevity.