As we all know, human life begins with fertilized eggs, but how did fertilized eggs develop into complex organisms with more than 200 cell types and 36 important organs? This process is one of the biggest problems in life science. ?
Scientists have known that development requires the orderly expression of genes in the human body at a specific time and place according to a set procedure. This process is called "gene expression programming". Similar to computer programming, the human body has a set of "programming language" for setting gene expression-also known as "chromosome open state". It is reported that the research results published by Professor Liu Jianqiao's team have interpreted how this "programming language" guides the gene expression of human embryos. It is reported that about two days after human fertilization is very special. The cells of this period are very different from all other human cells. During this period, there is almost no gene expression in the embryo. So how to express human genes, which genes are expressed first and which genes are expressed later, has always been a difficult point for scientists to study this process. ?
In this study, with the approval and guidance of the Ethics Committee, the researchers took samples from 82 infertile couples (female tubal obstruction, normal sperm and eggs). In order to find the "switch" of gene expression, the research team established the detection method of ultramicro cells, and finally found the key molecule "Oct4" that started the expression of human genome. It was found that the genes that appeared earlier in the evolution process would be expressed first, while the genes that appeared later often expressed later, that is, this study studied the activation mechanism of human embryonic genome expression for the first time in the world.