However, although we have mastered cloning technology and have continued to appear cloned animals over the years, we have never cloned humans. What's going on?

From a purely principle point of view, cloning is actually very simple, that is, extracting somatic cells from organisms, and then producing offspring that are exactly the same as the parent gene through asexual reproduction. Of course, the actual operation is definitely not as simple as the principle. Although the actual cloning technology is relatively complex, humans have mastered cloning technology decades ago. However, although we have mastered cloning technology and cloned animals have been constantly appearing over the years, we have never cloned human . What's going on?

clone Arctic wolf

Harbin Polar Park In 2006, two wild Arctic wolf wolves were introduced from Canada. They were named " Maya " and "Hal". These Arctic wolf are survivors of the Ice Age, with strong survivability and are mainly distributed in the Arctic region. We know that there are polar day polar night in the two poles of the earth, that is, the time of a year is only one day and one night, while one day is half a year, and one night is also half a year. For most organisms, it is difficult to survive in the Arctic region. On the one hand, it is difficult to withstand such cold temperatures, and on the other hand, it is also very difficult to survive in a dark night for half a year. For example, it is difficult to find food. But these Arctic wolves can live well in these extreme environments. Even if there is no sufficient food at the Arctic night, these Arctic wolves can survive.

These Arctic wolf have average sizes and are medium-sized wolf among the subspecies of gray wolf , with an average weight of between 35 kg and 45 kg. Although Arctic wolf has strong survivability, due to the wild environment, the lifespan of Arctic wolf in the wild is relatively short, usually about 7 years. However, if it is artificially raised, the lifespan of the Arctic wolf will be relatively long, which can exceed 17 years.

06 The two Arctic wolves introduced in Harbin Polar Park have now entered the old age, and there is not much time left for them. In order to "retain" Arctic wolves, the staff intend to "continue" Arctic wolves through cloning technology, and it has been successful. On June 10 this year, the world's first somatic cloned Arctic wolf "Maya" was born in the Arctic. On September 28 this year, the cloned Arctic wolf "Maya" met with the public in Harbin Polar Park. The situation of the cloning of the Arctic wolf "Maya" is roughly as follows:

1. Donor cells were extracted from the skin sample of the wild Arctic wolf "Maya" introduced by Harbin Polar Park;

2. Extract oocyte from a female dog in estrus, and the oocytes were decumed and nucleated. Then the donor cells were injected into the oocytes that had been ennucleated. The somatic nucleus and the ennucleated oocytes were combined to obtain a new embryo;

3. Finally, another beagle dog completed surrogacy, and finally the cloned Arctic wolf was born. After careful care of the staff, the cloned Arctic wolf had obvious physical characteristics and good health.

Why doesn’t people clone?

saw the birth of cloned Arctic wolf, and it has passed a "hundred days". Now its indicators are normal and very healthy. Some friends may start to think of this question in their minds. Since animals can be successfully cloned, humans have mastered cloning technology for decades, why haven't they cloned humans? If we can clone people, wouldn’t it be great if we can “continue” our lifespan through cloning technology when we are old and about to pass away?

seems wonderful and exciting, but the cloning technology is not as perfect as imagined. First of all, although the cloned new individual looks almost the same as the person who provides genetic information, it is a brand new individual with independent thoughts, which is actually equivalent to a "twin" that has been separated by several years or decades. So, cloning doesn't really make us "eternal life".

Secondly, the cloned new individuals may still face many problems.Taking the Arctic Wolf cloned this time as an example, there were actually two cloned small Arctic wolfs born this summer, but one of the cloned Arctic wolf unfortunately died due to the hemolysis of the newborn. This cloned Arctic wolf "Maya" has become the focus of everyone's attention. Now this small cloned Arctic wolf has successfully passed the "100 days" and is in good condition. In addition, the cloned Arctic wolf from another Arctic wolf, "Hal", was also born last month.

Of course, it is just the beginning now. Will these cloned Arctic wolf encounter any problems in the future? It is actually hard to say, and it may be like cloned sheep Dolly.

Speaking of cloned sheep Dolly, I believe everyone still remembers it. After all, there are knowledge points about Dolly sheep in middle school textbooks. The cloned sheep Dolly is the first animal born in the world to be transplanted with through cell nuclear transplantation. Its birth is not only of great significance to embryology and medicine. If we can combine these cloning technologies well with genetically modified technologies, it can theoretically benefit humans. But in fact, the life of cloning sheep is not as beautiful as we imagined. On the contrary, its life seems to be very sad.

The cloning process of Dolly sheep is similar to the previous cloned Arctic Wolf. Both are extracted from one sheep to donor cells, and receptor cell is extracted from another sheep, and then the donor cells and recipient cells are combined to obtain the embryo through a series of operations. Finally, the obtained embryo was transplanted into the uterus of another ewe and developed further, and Dolly was born.

Dolly sheep was born in July 1996, made its first public debut in 1997, and then was "euthanized" in February 2003. Dolly sheep actually only lived for more than 6 years. In comparison, ordinary sheep can live up to 11-22 years. Dolly Sheep, who had only lived for more than 6 years, developed a series of "agency diseases" in the late stage, which made many people start to think about what age is the real life span of Dolly Sheep who died in her prime? Is its lifespan calculated by the time of birth or the age of the sheep who was given the donor cell? Dolly sheep was cloned using somatic cells of a 6-year-old ewe. If the lifespan of Dolly sheep is calculated based on the birth time, it has only lived for more than 6 years, and Dolly sheep is considered to have died early. If the age of the sheep provided with donor cells is included, the lifespan of Dolly is 11-12 years old. In this case, Dolly will be considered a dead end.

This is a difficult question that scientists have not found yet. In addition to these technical issues, cloning humans also faces many problems, such as the problem of ethics and morals . After the birth of Dolly, cloned sheep, many people thought that cloning might not be far away, but in fact, more than 20 years have passed, there is no sign of cloning, and no one said he wanted to clone. What is blocking in front of you may be a matter of ethics.

Just imagine, if you start cloning people, then the cloned new individual with your own thoughts and souls will lead to chaos. It is completely impossible to say whether it is a child of a gene provider or a sibling. It's a child, but it doesn't go through the ten-month pregnancy process, it's a sibling, and the age difference may last decades, and the genes are almost the same. In addition, there are many deeper problems, which I will not explain them one by one here.