A team of genetic researchers headed by Dr Joao Pedro de Magalhaes from the University of Liverpool, UK, has sequenced the genome of the mysterious bowhead whale (Balaena mysticetus).
Bowhead whales (Balaena mysticetus). Image credit: U.S. National Oceanic and Atmospheric Administration.
The bowhead whale, also known as Greenland right whale or Arctic whale, is a species in the right whale family Balaenidae.
This species has a dark body and a distinctive white chin. Unlike most cetaceans, it lacks a dorsal fin.
It lives in ice-covered waters of the Arctic and near-Arctic, and spends most of the summer in relatively ice-free waters of seas adjacent to the Arctic Ocean.
The species has a massive bow-shaped skull that is over five meters long and about 35 percent of its total body length. This large skull allows it to break through thick ice with its head. It also has a 40-50 cm thick blubber layer, thicker than any other whale’s blubber.
Bowhead whales reach sexual maturity at about the age of 20 years, when they reach a length of about 14 meters.
Females generally have one calf every three-four years after a gestation period around 13-14 months. Calves are usually about four meters long at birth and weigh about 900 kg.
Adults grow to about 15-20 meters long and weigh up to 100 tons.
The average and maximum lifespan are unknown; however, some evidence suggests that they can live up to 200 years.
Now, Dr Joao Pedro de Magalhaes and his collaborators have sequenced the bowhead whale’s genome and compared it with those from other shorter-lived mammals.
It is thought that large mammals, such as whales, with over 1,000 times more cells than humans, have a lower risk of developing cancer, suggesting that these creatures have natural mechanisms that can suppress disease more effectively than those of other animals.
Sequencing of the bowhead whale showed changes in genetic information that related to cell division, DNA repair, disease and ageing that with further analysis, could help inform future studies in longevity and cancer resistance.
“Our understanding of species’ differences in longevity is very poor, and thus our findings provide novel candidate genes for future studies,” said Dr de Magalhaes, who is the senior author of a paper published in the journal Cell Reports.
“My view is that species evolved different tricks to have a longer lifespan, and by discovering the tricks used by the bowhead we may be able to apply those findings to humans in order to fight age-related diseases.”
He added: “the bowhead’s genome is the first among large whales to be sequenced, so this new information may help reveal physiological adaptations related to size that we have not been able to study in any great detail before.”
“Whale cells have a much lower metabolic rate than those of smaller mammals, and we found changes in one specific gene involved in thermoregulation (UCP1) that may be related to metabolic differences in whale cells.”
“This might allow us to see how and why bowhead whales and other similar creatures have sustained such an enormous size.”
The scientists would next like to breed mice that will express various bowhead genes, with the hopes of determining the importance of different genes for longevity and resistance to diseases.
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Keane M. et al. 2015. Insights into the Evolution of Longevity from the Bowhead Whale Genome. Cell Reports 10, 112-122; doi: 10.1016/j.celrep.2014.12.008
