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The secret to longevity may be found in the bowhead whale

By Karen Graham     Jan 6, 2015 in Science
Possibly the longest-living mammal on Earth is the bowhead whale. Sometimes living more than 200-years, the bowhead has only recently been studied in depth. Now, the complete genetic blueprint of this giant of the sea has been mapped.
Not only do bowhead whales have an extraordinarily long life, but scientists have wondered for many years how the large Arctic marine mammals are able to avoid many of the killing diseases that humans get as they age.
The bowhead whale is the second heaviest mammal on Earth, behind the blue whale. The bowhead reaches up to 66 feet in length and can weigh from 50 to more than 100 tons as an adult. They are primarily black in color with the upturned part of the lower jaw being white. Bowheads are filter feeders and consume huge amounts of zooplankton.
Researchers have now mapped the entire genome of the great marine creature, a step towards perhaps finding clues to its longevity and ability to maintain and repair itself at the cellular level. Their research was published today, Jan. 6 in Cell Reports.
Figure 1. Phylogeny of Mammals Used in
Codon-Based Maximum Likelihood Comparison
of Selective Pres...
Figure 1. Phylogeny of Mammals Used in Codon-Based Maximum Likelihood Comparison of Selective Pressure Variation The number of candidate genes under positive selection on each lineage is indicated.
Keane et al., 2015, Cell Reports 10, 112–122
According to The Verge, Joao Pedro de Magalhaes, a co-author of the study and a geneticist at the University of Liverpool, in the United Kingdom says, "We discovered changes in bowhead genes related to cell cycle, DNA repair, cancer, and aging relative to other species of whales."
Mads Peter Heide-Jørgensen is a biologist with the Greenland Institute of Natural Resources and the University of Copenhagen. He said, "Bowhead whales have probably 1,000 times as many cells as humans, but they apparently have an anti-tumor response at the cell level that is far more efficient than what is found in humans."
To sequence the genomes, researchers chopped samples of bowhead whale DNA into 4.0 billion tiny particles. The particles are called nucleotides. The DNA segments were then sequenced and then put together by computers. This then gave scientists a "blueprint" of the bowhead genome. The bowhead's blueprint, or genome was then compared to other whales, such as the orca and minke whales.
An exciting discovery was made when the bowhead genome was compared to other whale species and other mammals. Alterations were found in key genes in the bowhead that could be relevant to aging and cancer. There were also differences in cell repair and cell cycles. The scientists said the bowhead is the largest mammal to have its genome mapped thus far, reported Reuters.
"By identifying novel maintenance and repair mechanisms, we hope to learn what is the secret for living longer, healthier lives and may be able apply this knowledge to improve human health and preserve human life," Magalhães added.
The researchers plan to create mice with bowhead genes. "Mouse studies, I think, would be ideal to determine if these genes emerging from the bowhead genome can protect against age-related diseases or even promote longevity," says Magalhaes.
Now that genome sequencing is becoming more affordable, many more species can have their genomes mapped, leading to that much more of an in-depth study of life itself. But whales, who went from being terrestrial mammals to aquatic mammals are very interesting, and scientists are particularly interested in the environmental changes that took place at the cellular level.
More about bowhead whale, Longevity, Dna sequencing, transcriptome, maintenance and repair