Naked mole rats are probably the ugliest rats, their hair is sparse and slender, so that they look completely naked, you can even see the folds on their skin, it looks very unappetizing.
However, naked mole rats are probably one of the most amazing animals on the planet, looking underground for large rhizomes to feed on for a long time, and with the regenerative effect of the rhizomes themselves, they can eat for months or even years.
These foods are no better than other rodent foods, and the living environment of naked mole rats is not very superior, but their lifespan is 10 times that of ordinary rodents, and the longest even reaches more than 30 years old. These guys look hard to age and hardly get cancer.
So what is the divine naked mole rat? Why do they live so long? Why can naked mole rats even help humans overcome cancer?
1. What is the divine naked mole rat?
Naked mole rats, scientifically known as African naked molecular rats, are mainly distributed in Kenya, Ethiopia and other places in Africa, and they stay underground almost their entire lives. The burrow of the naked mole rat can be as deep as 1.8 meters, where it is small and dark, humid and oxygen-deficient, and it is this harsh environment that allows the naked mole rat to evolve a super survival ability.
First, naked mole rats have almost completely abandoned body hair and body temperature, they are no longer obsessed with maintaining a stable body temperature like other mammals, they are cold-blooded animals that become warm.
Of course, this is related to the relatively stable temperature of the underground environment in which they live, and they can regulate their body temperature by migrating. If the temperature inside the cave is high, they will go looking for a cool place; If it's cold in the cave, they migrate downwards to warmer layers.
Secondly, naked mole rats are fully adapted to the underground environment. In the cave, there will be a lack of oxygen, and the naked mole rat is very resistant to hypoxia. Regular mice can survive only a few minutes in an anaerobic environment, while naked mole rats can survive for 18 minutes in an anaerobic environment.
In general, the energy required for animal activities mainly comes from glucose, and the process of converting glucose into energy requires oxygen, without which animals cannot obtain energy from glucose.
The transformation mechanism of naked mole rats is different, they can obtain energy through the conversion of fructose in an oxygen-free environment, and when fructose is converted, oxygen is not required, so naked mole rats can survive for a long time in hypoxic caves.
In addition, due to the harsh underground environment, coupled with the food shortage in the African desert area, the naked mole rat's metabolism level is extremely low. In order to maintain a low level of metabolism, they actively shut down some useless organs, such as in dark caves, visual ability is completely useless, so naked mole rats evolved blind.
Not only that, naked mole rats feel pain in order to avoid bumping into them while traveling through the burrow, but also to save energy, they even shut down some sensory systems, such as additional neuroreceptors, which makes them less sensitive to pain.
2. Magical true social animals
The strong ability to survive is not the most amazing thing about naked mole rats, but the most amazing thing is that naked mole rats are one of the few true social species among mammals, they have a social structure like bees or ants.
A naked mole rat cave may be home to a few to hundreds of members. In this group, there is only one female with reproductive ability, and one or more males with reproductive ability.
Most of the remaining naked mole rats have underdeveloped reproductive organs and cannot reproduce, and they are like worker bees in bee colonies, which scientists call "worker mice".
And the female naked mole rat who is high above and holds reproductive rights is called the "queen rat". The urine of the rat contains substances that inhibit the reproductive function of the worker mouse, allowing it to sit in this position.
Worker rats are responsible for the day-to-day nest work, including helping the rats and taking care of the children. Typically, young rats are cared for by the queen for the first month of life and thereafter by worker mice.
However, for mammals, the instinct to rearing young is stimulated by estrogen. But the reproductive function of worker mice is inhibited, and how do they obtain hormones to stimulate child-rearing behavior? This may be related to the feces of rats.
It may sound disgusting that naked mole rats eat the droppings of their companions, but there are still many nutrients in naked mole rats that are not fully digested, and it is not surprising to use nutrients in feces in the underground of African deserts where food is scarce.
In fact, in addition to using the nutrients that may be present in the feces, naked mole rats also use feces to obtain the unique smell of their nest to distinguish invaders.
It is precisely by taking advantage of the habit of group members to eat the feces of their peers that the queen rats transmit the estrogen in their bodies to the worker rats through feces, so that they can willingly take care of their cubs.
However, although the rat queen is very powerful and has a very long life, there will be a day when life will come to an end. The death of the rat queen does not bring an end to the group, but it does bring chaos.
Those females, who were once suppressed, began to regain their abilities and instincts. They begin to fight each other until they decide on the alpha individual and become the new rat queen of the group.
The queen will mate with the male, and its body will also change, becoming as fertile as the original queen. And it will inherit everything from the entire nest and assume the responsibility of breeding.
3. Why do naked mole rats live so long?
Most of the rodents have a lifespan of about 2~3 years old, while the naked mole rat can live up to 30 years old, ten times that of ordinary rats, why do they live so long? The answer to the question is that naked mole rats don't get cancer, which gives them a long lifespan.
Here we need to point out the basic mechanism of cancer: cancer actually starts from genetic errors, animal cells are dividing all the time, normal cell division requires growth signals, and at the same time inhibits signals to prevent excessive cell division and tissue overgrowth.
But if a cell mutates during division and becomes a cancer cell, the normal growth process of animal tissue will be disrupted. The characteristics of cancer cells are that there are especially many growth signals, and they are not controlled by inhibitory signals, so cancer cells will continue to divide and grow to form tumors.
In this way, the longer the animal lives, the greater the chance of cancer, because a longer lifespan means more cell divisions and a greater chance of becoming cancerous. The great increase in human life expectancy is also the main reason for the increasing number of cancer patients in our modern society.
In general, the longer the life of naked mole rats, the greater the risk of cancer, but why do they live 10 times longer than other rodents and do not die from cancer?
In general, due to the mechanism of contact inhibition, normal animal cells stop proliferating when they come into contact with each other, as do tumor cells, so benign tumors cannot be considered cancer.
But if the cells become cancerous, the mechanism of contact inhibition will fail, and even if cancer cells come into contact with each other, they will continue to increase in value and even metastasize to other parts.
However, the cells of naked mole rats secrete a hyaluronic acid dominated by polysaccharides, which is the main non-protein component of the extracellular matrix. It is this special substance that gives the cells of naked mole rats a different ability to inhibit contact, even cancer cells, can not proliferate indefinitely in naked mole rats.
The skin connective tissue of naked mole rats contains a large amount of hyaluronic acid in the form of high molecular weight, while the corresponding hyaluronic acid content in ordinary mice or humans is less than one-fifth of that of naked mole rats.
This hyalic acid molecule in naked mole rats is not only larger than that of humans and other mammals, but also in more amounts. This high molecular weight form of hyaluronic acid inhibits the transformation of normal cells into cancer cells. If the hyaluronic acid in the naked mole rat is removed, the normal cells of the naked mole rat are no longer inhibited when they transform into cancer cells.
Studies have shown that this hyaluronic acid in naked mole rats can increase cell-to-cell sensitivity, and once the cells are too close, it will prevent the cell from dividing, and the fewer times the cell divides, the less likely it is to become cancerous.
In the future, human beings may be able to control the incidence of cancer by studying this hyaluronic acid and regulating the content of hyaluronic acid, which may become a new way to prevent and treat cancer.