Scientists have discovered that a mouse model of miRNAs gene knockout can be obtained through TALEN technology, successfully solving the problem of small genes (such as miRNAs) and gene knockout containing repetitive sequences in mice in the past.
MiRNAs are endogenous double-stranded RNA molecules with a length of about 21-25 nt. They have a typical hairpin structure and can regulate the expression of other genes. It is speculated that miRNAs regulate one third of human genes. There are many forms of miRNAs, from the most primitive pri-miRNA to pre-miRNA (microRNA precursor) after one processing, and the pre-miRNA is digested with Dicer enzyme to become mature miRNA. miRNA specifically binds to the mRNA of the target gene, thereby inhibiting post-transcriptional gene expression, and plays an important role in regulating gene expression, cell cycle, and biological development timing.
Hiroshi Asahara and his researchers used TALEN technology to target a gene desert and miRNAs to obtain miRNA knockout mice with a high success rate. The researchers also confirmed that allelic mutations caused by microinjection of TALEN RNA can be passed on to the next generation of mice. At the same time, the study showed that it is consistent with the maturation mechanism of miRNAs. As long as TALEN is used to target the sequence of one of the mature miRNAs on the miRNA precursor and introduce mutations, the function of the entire mature miRNAs will be knocked out. This is for studying the effects of miRNAs on genes. Regulation provides an effective technical method.