The longest-lived mammal on Earth is the bowhead whale (Balaena mysticetus), which lives more than 200 years. How do bowhead whales enjoy such longevity in the frigid Arctic Ocean? Scientists have found the secret in their genes. They have fewer cancer-causing gene mutations, and even when mutations occur, they are repaired immediately. In other words, they break down less often to begin with, and when they do, they are quickly fixed as they go.
A joint research team led by spouses Professor Vera Gorbunova and Professor Andrei Seluanov of the Department of Biology at the University of Rochester and Professor Jan Vijg of the Department of Genetics at the Albert Einstein College of Medicine said on the 30th in the international journal Nature, "We found that the bowhead whale's remarkably long lifespan is thanks to enhanced ability to repair DNA mutations."
◇ Vulnerable to mutations but excellent at repair
Bowhead whales measure 15–24 meters in length and weigh more than 80 tons. With blubber up to 50 centimeters thick, they can live in the icy waters of the Arctic Ocean. DNA accumulates mutations over time, which leads to cancer. Because bowhead whales are enormous and long-lived, they would be expected to have many DNA mutations. However, bowhead whales are not prone to aging-related diseases such as cancer. The researchers found the secret in whale cells: a cold-activated protein that helps repair damaged DNA.
Bowhead whales are difficult animals to study. Because they are so large, they cannot be kept and observed in a laboratory. Above all, as an endangered species, they are not easy to study in the wild. The researchers received help from the Inuit, Indigenous people of the Arctic. Each fall, Inuit living in northern Alaska hunt bowhead whales with government permits. The Inuit have hunted whales in the Arctic Ocean for more than 1,000 years.
The University of Rochester team collected samples from bowhead whales caught by the Inuit and cultured bowhead whale cells in the lab. At first, they thought whales live long because they have resistance to cancer. Contrary to expectations, the number of oncogenic mutations needed for whale cells to turn into cancer cells was smaller than in human cells. In other words, the mutation threshold for cancer is lower than in humans.
Even so, whales are not prone to cancer. The researchers found that the chance of oncogenic mutations occurring in bowhead whales is inherently low. In particular, whale cells had a stronger ability to repair damaged DNA. Whales may be vulnerable if mutations occur, but they effectively block such mutations from arising in the first place.
The team also found that the CIRBP protein plays a key role in repairing damaged DNA in bowhead whale cells. This protein operates in low-temperature environments like the icy seas where bowhead whales live. Bowhead whales had 100 times more of this protein than humans. When CIRBP was induced in human cells, DNA repair capacity improved. When the protein was expressed in fruit flies, their lifespan increased. Resistance to radiation, which can induce DNA mutations, also rose. Although fruit flies are small insects, they share 60% of their genes with humans and are widely used in biological and medical experiments.
Professor Zhiyong Mao of Tongji University said in Nature the same day, "Everyone knows bowhead whales are extremely long-lived, but no one knew why," adding, "This study shows that DNA repair mechanisms that enhance genomic stability are a highly effective strategy enabling extreme longevity." Mao is a former student of Professors Gorbunova and Seluanov.
◇ The secret to longevity aligns with land-dwelling mole rats
The notion that DNA repair capacity is a key to longevity has also been confirmed in a land-dwelling longevity champion: the naked mole rat (Heterocephalus glaber), which lives underground. Native to East Africa, this animal is 8–10 centimeters long and weighs 30–35 grams, and as its name suggests, it has little hair. Although it may look unimpressive, its lifespan is an astonishing 32 years—more than 10 times that of other rodents of similar size. In human terms, that would be equivalent to living more than 800 years.
Mao announced in Science on the 10th that "we found the naked mole rat's secret to longevity stems from mutations in cGAS (cyclic GMP-AMP synthase), an enzyme that detects external invaders and triggers immune responses."
cGAS detects the DNA of cancers or viruses outside the cell nucleus. But inside the nucleus, cGAS shows the opposite behavior. In humans and mice, it suppresses DNA repair, increasing the risk of gene mutations and cancer. In contrast, in the naked mole rat, mutations in this enzyme make it do the opposite and prevent cancer. It is as if a troublemaker transformed into a dutiful helper.
The DNA repair abilities of whales and mole rats may be far more powerful than we think. There may even be bowhead whales over 300 years old. In 2019, researchers at the Commonwealth Scientific and Industrial Research Organisation (CSIRO) reported in Scientific Reports that the average lifespan of bowhead whales is 268 years.
The researchers analyzed the genes of 252 vertebrate species and identified 42 genes related to lifespan. Based on this, they built an animal lifespan clock, which predicted that bowhead whales live 268 years—57 years longer than previously expected.
Mao said, "To understand whether CIRBP, which contributes to bowhead whale longevity, could also benefit humans, further research is needed to elucidate how this protein works," while adding, "Overall, these findings highlight the importance of DNA repair in longevity and cancer prevention." Gorbunova said, "The core message of this study is that there is room for improvement for us," adding, "As research advances, humans' DNA repair capacity could also be enhanced."
References
Nature(2025), DOI: https://doi.org/10.1038/s41586-025-09694-5
Science(2025). DOI: https://doi.org/110.1126/science.adp5056
Scientific Reports(2019), DOI: https://doi.org/10.1038/s41598-019-54447-w