Naked mole rat genome may point way to long, healthy life

(Also, youre a naked mole rat.)How this collection of traits and behaviors came to exist in a strange rodent found only in a Horn of Africa has been a mystery. Now, biologists have a tool for unraveling it and what they find might one day prove useful to tellurian medicine.A team of 36 scientists working on 3 continents on Wednesday published a genome of a naked mole rat, a latest and perhaps a most exotic organism to have its entire DNA sequence transcribed.Its a treasure trove for cancer and Alzheimers research. Its got so much information that we can now go and mine to test all kinds of theories about aging and disease, said Rochelle Buffenstein, a researcher at a University of Texas Health Science Center in San Antonio who participated in a project.Having a genome raises a possibility of finding treatments that might prevent cancer in people and possibly even extend lifespan, said Vera Gorbunova, a cell biologist and mole rat researcher at a University of Rochester, who was not involved.Mole rats are hairless and buck-toothed rodents four inches prolonged that live in underground colonies in arid sections of Kenya, Ethiopia, Somalia and Eritrea. Their social structure is a mammalian equivalent of an ant colony. Theres a queen who takes two or 3 male consorts and is a only female to reproduce. She lords over a rest of a realm which can be as large as 200 animals so that a other females cease ovulating and a males give up.Mole rats can survive in environments low in oxygen (as little as 8 percent as opposed to 21 percent in a atmosphere) and laden with ammonia and carbon dioxide. Unlike other mammals (but like reptiles) they have a hard time regulating their body temperature. They have to move toward a warmer upper reaches of a burrow, or huddle with their brethren, when they get cold.But their most unusual features are extreme longevity and apparently complete resistance to developing cancer. Naked mole rats can live more than 25 years; mice live about four. Buffenstein said shes never found a ! malignan t tumor in a mole rat in her 30-year-old colony, which now has 2,000 animals. In a recent experiment, a group of mole rats had patches of skin painted with a chemical carcinogen at a dose 1,000 times stronger than what causes skin cancer in mice. None developed tumors.A study published in 2009 found that naked mole rats had a molecular anticancer mechanism not present in mice or people. But a first look at a species full complement of 22,561 genes shows thats just a beginning.There are changes in genes concerned in maintaining telomeres, a tails of chromosomes that determine how prolonged a cell lives. There are changes in genes concerned in marking damaged proteins for destruction. Theres an increase in chaperone genes that keep proteins folded into their right shapes. There are genes that appear to let them maintain stem cells longer than other rodents.The researchers looked at 54 tellurian brain genes that either become more or less active as a person ages. In a mole rat, 30 of those genes remain stable throughout life, and changes move in a direction opposite to what occurs in tellurian brains.Mole rats have 96 gene families unique to a species. Interestingly, they and tellurian beings also share 178 gene families that neither mice nor other rats have.Now we have to go back and study each one of these in detail, said Vadim N. Gladyshev, a researcher at Harvard Medical School who headed a project, whose report appears in a journal Nature.In many cases, a unusual features of a naked mole rat genome make perfect sense.The species lacks many genes associated with vision, although it still has ones that allow it to perceive light. Genes concerned with setting circadian rhythms formed on daylight and darkness are gone. A gene that regulates Substance P a protein concerned in a perception of pain caused by caustic chemicals is very different. That presumably allows a animals to tolerate breathing air loaded with ammonia from their urine.They also lack many bitter-taste receptors. Buffenstein said that p! robably makes underground tubers, a staple of a mole-rat diet, more palatable. Many of those roots are loaded with bitter, plant-protecting compounds. On a other hand, they appear to have genetic enhancement of sweet receptors. This doesnt surprise a Texas researcher.My colonies go absolutely nuts for sweet things, she said.


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