For the first time, the global mammalian complete chromosome programmable connection

【Technological frontier】

On August 26, the international academic journal "Science" published a pioneering achievement of Chinese scientists -Researcher Li Wei and Zhou Qi Researcher team in the Institute of Animal Research of the Chinese Academy of Sciences and the Beijing Institute of Stem cells and Researchers in Beijing for the first time in the world to achieve the first time in the world The comprehensive chromosomal connection of mammals, and created mice with a new nuclear (chromosome group).

Some comments believe that this work means that the breakthrough of biological engineering technology is breaking through again, and in order to deeply understand the large -scale reconstruction of mammalian chromosomes such as the large -scale reconstruction of mammalian chromosomes, such as the molecular mechanism of the growth, development, reproduction and evolution of species, etc. Synthetic biological research strategies have laid the corresponding technical platform.

The complete dyeing weight of mammals for the first time

To understand this achievement, we must first understand a concept -chromosomal rearrantement. Li Wei introduced that the chromosome weight row refers to the break of chromosomes and connects with other chromosomes to form a new chromosomal.

In the long process of biological evolution, the dyeing weight row is an important factor that causes quality changes and leaps. But for individuals, dyeing weight is more of the disease -some types of children with leukemia and infertility of children are caused by dyeing weight.

To understand the mystery of color dyeing weight, it can further reveal the mystery of human evolution, and it can also make a leap in the treatment of various diseases. Therefore, dyeing weight is the focus area of ​​biologists. In recent years, the precise re -arrangement of chromosomes has been the first to be successful on genomic composition and a polarized yeast. However, because mammalian genome is much more complicated than yeast genome, the overrun of complete chromosomes on mammals has not been successfully achieved.

After years of hard work, Chinese scientists have first achieved the complete dyeing weight of mammals worldwide in the world, and have achieved new breakthroughs in synthetic biology. "Our research breaks the technical bottleneck, and uses mouse gangbang embryo stem cells and CRISPR gene editing tools to successfully connect the longest chromosomes No. 1 and 2, and the medium -length 5 and 4 chromosome Perform the first and tail connection, and it is also found that chromosome breaks and re -connection may occur during chromosomal connection. "Li Wei said," The research results show that two independent chromosomes from mice can be used as non -homologous after gene editing. The end connection repair method is connected to a chromosome. "

In understanding evolution, design life, and disease treatment, it will have a huge impact

On this basis, the researchers further studied the impact of a specific dyeing weight connection.

First of all, researchers have confirmed that the chromosomes of mammalian cells are not longer and better, which will cause abnormal cell division. Li Wei introduced that at the level of cell surface type, the multi -energy gene expression and differentiation of stem cells after chromosomal connection have not changed significantly, while the longest chromosomal connection (2 and No. 1 chromosomes connect) The rate is significantly accelerated, and it has become a multiplied multiplication in the twice the embryo stem cells and nerve stem cells. "This phenomenon is caused by abnormal cell division due to the long length of chromosomes, which also proves that the length of the chromosomes of mammalian cells has a certain limit. For mouse cells, the upper limit of the chromosome length is between 308.3MB ~ 377.6MB. "

Secondly, scientific researchers "created" mice with a new and unique chromosome group. According to Li Wei, in order to solve the impact of specific chromosome weight on the animal surface type, researchers successfully obtained the mice connected to the chromosomal connection by the polymeter stem cells -it seems to be with ordinary mice It is no different, in fact, there is a new and unique chromosome group that has never existed in the world.

Studies have found that different chromosomal connections have different effects on mice. The longest of the longest chromosomal connection (No. 2 and No. 1 chromosomal connection) makes the embryo development cannot be carried out normally. The break is re -connected to the 17th chromosomes, and the generated mice showed the abnormal growth curve and behavior. Mice No. 4 and No. 5 chromosome did not show obvious abnormalities.

At the same time, the connected chromosomes can be passed to the offspring, and further mating can produce pure mice. Li Wei said: "This proves that the connection of the two chromosomes will not cause absolute reproductive isolation, but the genital force of mice carrying chromosomes with chromosomes has dropped significantly. Further exploration and found that although the chromosomes after connection can still be separated from the two separations from the two separations. The homologous chromosomes are performed normally, but the separation of homologous chromosomes after the federation will occur abnormal. "

Finally, the researchers also comprehensively analyzed the trend of chromosomal space structures in embryonic stem cells, neuroplastic cells and brains. Studies have found that changes in spatial structure of chromosomes weaken with differentiation.

Li Wei said that this study strictly complies with my country's laws and regulations and relevant state regulations, and complies with my country's and international ethical norms."Our research has established new technologies for comprehensive chromosomal connection of mammals for the first time, and realized the editing of large -scale genomes, adding new research tools to mammalian synthetic biology.Mammalian synthetic biology for chromosomal design synthesis provides an important reference; through re -constructing chromosome weight emission events in the laboratory mouse model, it helps understand the evolutionary chromosomal fusion, which also proves the correlation between the chromosomal weight and reproductive isolation.It provides new ideas for evolutionary biology research. And chromosomal precision reperfrontation technology is an animal model for establishing dyeing and weight -renovation diseases, studying the pathogenesis of infertility and tumor diseases caused by dyeing weight.New technical means. "(Newspaper, Beijing, August 26th. Reporter Qi Fang)

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