After a gestation of 70 days, ten Naked Mole-rat pups were born at BIOPARC Valencia.
The new family makes their home in a special exhibit that recreates the underground life of the African Savannah. Part of the galleries that houses them allows visitors to see the intricate tunnels and rooms where the rodents live and raise their young.
The Naked Mole-rat (Heterocephalus glaber) is a burrowing rodent native to parts of East Africa. It has a highly unusual set of physical traits that allow it to thrive in a harsh underground environment and is the only mammalian thermoconformer, almost entirely ectothermic (cold-blooded) in how it regulates body temperature. One of the most striking features is the skin that is almost free of hair and “transparent” for lack of an insulating layer of fat under it.
The Naked Mole-rat lacks pain sensitivity in its skin, and has very low metabolic and respiratory rates. The species is also remarkable for its longevity and its resistance to cancer and oxygen deprivation.
These curious rodents are the only mammals with a eusocial behavior, which is also a characteristic feature of insects. Like insects, the Naked Mole-rats live in colonies that have overlapping generations and make an organized division of labor and cooperative care of offspring. Likewise, there is only one reproductive female, the “queen”, and one to three breeding males or “drones”. The rest of the individuals are divided between “soldiers” and “workers”. The rest of the females are sterile, because the “queen” inhibits their reproductive capacity and a part of them ingests the excrements of the queen, which are rich in the sexual hormone estradiol, which activates them to be in “breeding” mode and to exercise of caretakers of the children of the queen.
The Naked Mole-rats longevity is superior to other rodents, up to 30 years, and the low presence of cancerous tumors were already known; thanks to a special gene, p16, which prevents the disordered growth of cells.
We also knew of the species’ resistance to the absence of oxygen. A human brain can die after 1 minute without oxygen, but the Naked Mole-rat holds up to 18 minutes without it and arrives at 5 hours with low oxygen levels. What we now know is that this is because this rodent changes its metabolism to anaerobic and uses fructose as energy as plants do, instead of glucose. These latest discoveries open avenues of investigation not only to increase survival, but also to possibly preserve our brain from the damage and degeneration produced by diseases that cause oxygen deficiency in neurons.