动物实验,DNA演化 z-bo 2020-08-19 514

　　The data set provided here is useful for researchers seeking to understand how mammalian regulatory DNA has evolved. The lack of detailed information from the different cell types that are comparable between humans and mice shows how to regulate thousands of mammalian genes through DNA components such as enhancers and promoters (regulating gene expression). The limitations of studying DNA profiles are limited.

　　Jeff Vierstra and colleagues (here is the Mouse ENCODE project) aim to solve the functional components encoded in the mouse genome and have overcome this challenge. The researchers used a site called DHS or DNase I, which usually marks gene regulatory regions to map the appearance of mouse regulatory DNA in 45 different mouse cell and tissue types. They compared mouse DHS maps with corresponding DHS maps of human cells and tissues. Compared with the affected gene, the number of DHS farther from the affected gene is much higher. This indicates that DHS, which has been preserved throughout the evolutionary history of mammals, may have different functions from the genes controlled by DHS that are closer to it.

　　This report explains why mouse research is not always replicated in humans. More importantly, the scientists say that their work has brought dawn to the elucidation of the functions of DNA regulatory regions. It is usually the genetic cause of common chronic diseases in humans. "Most of the differences between mice and humans are due to the regulation of gene activity, not the regulation of the gene itself."

　　In the early days of genetics, researchers tended to look for single or multiple gene mutations related to disease. Have. But if there is no "mission control center", genes will not be able to produce the right amount of protein at the right time and at the right place. Biya said: "From diabetes, ADHD to Parkinson's disease, most human diseases are caused by unconventional gene regulation. This phenomenon is becoming more and more obvious." Almost all human genes are present in mice. Corresponding genes, but protein coding genes account for only 1.5% of each genome. Based on this, combination drugs that can cure mice are generally ineffective in humans. According to the physical tissue network reported on November 20, Beijing time (Beijing time), in order to study these functional areas in detail, the research team has 124 types, including brain, heart, blood, liver, kidney and skin. The mouse cells were analyzed. The organization has collected more than 1,000 reports. The database shows the active position of genes in the DNA region, the binding of special proteins to DNA, and the occurrence of DNA replication. Takumi also invented a mathematical tool that can compare mouse and human tissue databases and identify the most similar areas between the two. Analysis shows that when mouse genes are in protein production and other intracellular processes, they are very similar to human activities, but when they are in cell surface activity, their radioactivity distribution is exactly the same. Show different modes.

　　"This is a discovery of broad significance. Researchers can use it to study cell-to-cell communication, immunity, cardiovascular disease, and many other diseases." The evolutionary mechanism has been carefully selected: the core cell process maintains the regulatory mechanism, and The rest of the process varies according to different needs. "

　　Mouse Surprisingly, mice and humans. The researchers also compared gene activity patterns in mouse cells and tissues, and found similarities between mouse brain and small intestine gene models in mouse and human brain gene models at the level of gene activity. The similarity between the two is much higher. This means that most genetic changes in evolution occur at the species or system level.