Background news :
A piece of international news yesterday subverted the traditional concept of human family succession — a British laboratory announced that for the first time, human sperm were cultivated in vitro using embryonic stem cells , which means that sperm may no longer need to be produced in a male body. But whether this kind of cellular substance can be called a qualified sperm in the true sense has raised doubts in the scientific circles at home and abroad. The basic judgment of experts from universities and colleges in Shanghai is that “artificial sperm looks similar in appearance but not in spirit.”
This time, researchers from Newcastle University and other scientific research institutions in the UK used embryonic stem cells with XY male chromosomes as “seeds” to prepare a “nutrient solution” composed of chemical substances and vitamins, so that the stem cells differentiated and turned into sperm. Under the microscope, this artificial sperm is similar to human sperm, with a head and a tail, and can swim.
Since embryonic stem cells mostly exist in the fetus , if this technology can be realized, the stem cells of the fetus in the abdomen can be extracted and its sperm can be produced before it is born. In addition, since the scientific experiment of reversely restoring human skin to the state of stem cells has achieved some success, it is theoretically possible to use skin cells to create stem cells and regenerate sperm.
Compared with the ethical doubts raised by the public on artificial intelligence, scientists have raised more technical doubts. Professor Zhou Guomin, director of the Department of Anatomy, Histology and Embryology, Shanghai Medical College, Fudan University, believes that there are many possibilities for inducing stem cell development in vitro, which may lead to changes in cell morphology and cell function. He introduced that the development process of sperm in the testis and epididymis is very complicated and needs to be regulated by various factors in the body. The absence of any link may lead to immature sperm. “This kind of artificial sperm may only be similar in shape, not in spirit, and may not have genetic functions, or some functions may be missing.”
Three years ago, the main members of the British research team used a similar method to create artificial sperm for male mice, inject them into female mouse eggs, and finally implant the resulting embryos into surrogate mother mice. During that time, they produced only seven pups out of about 400 fertilized eggs. One of the cubs died soon after birth, and the remaining six died after 5 months, while the average lifespan of normal mice is about 2 years. Given this, there is a big question mark over whether artificial sperm can help humans reproduce, or ensure healthy offspring. But experts also said that this study is still meaningful for further understanding the mechanism of sperm development and explaining the causes of immature sperm.