Bowhead whales (Balaena mysticetus) were once believed to live between 60 to 70 years just like other whales, but subsequent discoveries and research eventually revealed that these denizens of the Arctic seas can live to be 200 years old.
Besides their remarkable longevity and resistance to age-related diseases, these marine animals may also offer insight into how humans can have a long and healthy life, suggest researchers of a new study that mapped the complete genome of the bowhead whale and identified key differences in the bowhead's genes from those of other animals.
In the study published in the Jan. 6 issue of Cell Reports, João Pedro de Magalhães from the University of Liverpool in the UK, together with colleagues, sequenced the genome of the bowhead whale using tissues from whales that were killed in hunts in Alaska and Greenland. The genome was compared with those of nine other mammals, which included other cetacean species, cows, humans and rats, unveiling secrets on how the marine creature manages to live a long life and build resistance to disease.
The researchers, in particular, discovered a mutation in two of the bowhead's genes involved in DNA repair, cancer, cell cycle and aging process, which may be responsible for the animal's long lifespan and vitality.
The bowhead's unique mutation in the gene known as ERCC1, which is involved in the repair of damaged DNA, may provide protection against cancer, a disease that according to the American Cancer Society, strikes over 1.6 million Americans each year and causes more than half a million deaths yearly in the U.S.
Although a large number of people develop some forms of cancer in their life, whales have low prevalence of cancer regardless of the fact that the number of their cells is 1,000 more than those of humans and despite their long lifespan.
Magalhães and colleagues likewise found that the bowhead's PCNA gene, which is involved in DNA repair and cell growth, has a section of duplicated DNA. The researchers think that the duplication could slow aging.
"Our analysis identified genes under positive selection and bowhead-specific mutations in genes linked to cancer and aging," the researchers wrote. "Our results expand our understanding of the evolution of mammalian longevity and suggest possible players involved in adaptive genetic changes conferring cancer resistance."
Bowheads are considered endangered species in the U.S. and in many other countries.