Chinese people cannot live without pigs. The original meaning of "home" is to raise a pig in the house. Pigs are the most important livestock, providing humans with a large amount of animal protein and fat energy. But in addition to being eaten, pigs are also important experimental animals, playing a major role in carrying out life science research and improving human health and life extension.
The evolutionary history of pigs can be traced back to 40 million years ago. Archaeological evidence shows that domestic pigs originated from two wild populations in Europe and Asia 10,000 years ago. Wild boars were first domesticated in China. As early as the matrilineal clan commune period, China had begun to raise pigs, dogs and other domestic animals. The shape of the pottery pig unearthed at the Hemudu Neolithic Cultural Site in Yuyao, Zhejiang is very similar to that of a domestic pig, indicating that the domestication of pigs had already taken shape at that time. It was not until the 16th century that domestic pigs were brought to the Americas. In the 18th century, Europeans introduced Chinese pigs to the European continent, mated with local pigs, and developed modern pigs with high litter rates and high feed conversion rates, forming the mainstream pig breeds in the world today.
It is said that the invention of the gas mask was inspired by wild boar. When the wild boar smells a strong pungent odor, it digs the ground with its mouth. After the soil is kicked by the wild boar, its particles become softer, which plays a role in filtering and adsorbing the poisonous gas. The pig can therefore avoid the stimulation of the smell. . During World War I , the famous Russian chemist Nikolay Dimitrievich Zelinsky (Nikolay Dimitrievich Zelinsky) designed and manufactured the first batch of gas masks based on this discovery. . Nowadays, although the performance of adsorbent is getting better and better, its basic style of resembling a pig's mouth has not changed.
What are experimental animals? Experimental animals refer to animals that are raised in a "sterile" environment, have a clear genetic background, and are used for scientific research and scientific experiments. Research shows that the IQ of pigs is similar to that of 4-year-old humans, and "the genetic difference between humans and pigs is only 1%." In September 2019, Chinese scientists released the high-quality genome sequence of Guangxi Luchuan pigs for the first time. This provides key benchmark data for research in the field of pig genetics, and enables better use of pigs as model animals to carry out basic research at the molecular level, opening up new avenues for human health and disease research.
Pigs are one of the most important experimental animals. The cardiovascular system, digestive system, skin, nutritional needs, bone development, and mineral metabolism of domestic pigs are very similar to those of humans. Miniature pigs are highly similar to humans in terms of anatomy, physiology, and disease pathology, and are ideal model animals for human medical research. It is widely used in the research of diabetes, cardiovascular, hypertension, Parkinson's disease, tumors and other diseases.
We know that organ transplantation is the ultimate solution to many malignant diseases. However, the source of human organs is very limited, so scientists began to think about whether they can be replaced by organs from other animals. Although primates look closest to humans, most primates are too small and their organs cannot bear the metabolic needs of the human body. Chimpanzees and other great apes are endangered and rare animals, and their reproduction rates are low. It cannot meet the requirements of experimental animals in terms of scale and consistency. In addition, monkeys, orangutans, etc. are so closely related to humans that there are also ethical challenges.
Since "elder brother" Monkey can't count on him, he has no choice but to trouble "second brother" Zhu Bajie . Pigs have many advantages as human organ transplants: First of all, pig organs are just the right size, and their kidneys, hearts, pancreatic islets , nerve cells, etc. are almost identical in structure and function to the corresponding human organs, tissues, and cells and can be replaced. Human-derived organ donors; secondly, the anatomical structure, physiological indicators, and blood group antigens of pigs are also similar to those of humans, and can be genetically modified to improve the therapeutic effect of xenotransplantation; last and most importantly, pigs have a short growth cycle and are easy to raise , facilitates industrialization and reduces treatment costs.
At present, the research frontier on pigs is mainly focused on xenogeneic organ transplantation .In 2015, the world's first artificial biological cornea "Ai Xintong" independently developed by China was put into production. This cornea is made from clean and raised pig cornea. After transplantation, the patient can gradually fully integrate with his or her original corneal tissue to achieve Lifetime use. As of September 2019, Wuhan Union Hospital has completed more than 100 cases of porcine cornea transplantation. Although the initial transparency of the transplantation was not ideal, over time, the transparency gradually approached that of the human cornea, and the naked eye visual acuity could reach 0.4.
Distinguished Professor of Nanjing Medical University and Director of the Jiangsu Provincial Key Laboratory of Xenotransplantation Dai Yifan is an internationally renowned expert engaged in research on genetically modified large animals and xenotransplantation. In 2002, the research group led by him used the gene to knock out technology. , the cloned pig ( universal pig ) was bred in the United States and basically did not contain the "rejection gene". It was selected as one of the 100 major scientific discoveries in the United States "Science" that year. In September 2018, at the Japan Xenotransplantation Research Conference, teams from Meiji University and Kyoto City University announced that they had successfully developed pigs for human organ transplantation and are expected to enter the human production stage.
The World Health Organization pointed out that pigs have the potential to become a donor resource of high-quality organs, tissues and cells, which will provide a continuous supply for patients who are waiting for organ transplants. Perhaps in the future, "human face and pig heart" may become common, and the idiom "human face and animal heart" may no longer be a derogatory term, but a neutral term describing human health or organ composition.
