Photosensitive proteins help, and scientists can regularly recombine genes

in "The Water Otter", Song Jiang in Zhujiazhuang with a high hanging red lantern to direct the horse, and achieved victory. Ye Haifeng, a researcher at the School of Life Sciences at East China Normal University, recently published a paper in the journal Nature Communications as a communications author, saying they have developed a split Cre-loxP recombinant enzyme system that is regulated by far red light. This recombinant enzyme, which is integrated into the optical control system, can start the "battle" in the place where the LED is far red light, which not only achieves the effective control of gene recombination, but also solves the problems of biological toxicity, tissue organ specificity and poor tissue penetration that have plagued the academic community for a long time.since the implementation of the Human Genome Project, humans have read the genome sequence that transmits the "code of life", but it is not clear what each gene does.
In order to decipher the function of a gene, people study the specific function of a gene in life by indescensing it, looking at changes that occur in living organisms, or by tapping the gene directly into model animals to see what happens to experimental animals.
In Cre-loxP recombinant enzymes, the loxP sequence consists of 34 base pairs, consisting of 13 base pairs at each end of the reply and 8 symmetrical base pairs in the middle. Cre-loxP recombinant enzymes are able to specifically identify loxP sequences, so Cre-loxP recombinant enzymes are known as gene-editing artifacts that can perform targeted modifications to genes at specific sites, including knocking, insertion, flipping, and translocation.
Cre-loxP recombinant enzyme system is good to use, but the problem has come. Cre recombinant enzyme was discovered in 1981 from P1 phages and is not native to mammals. The loxP sequence is also derived from P1 phages. "Continued and stable expression of Cre recombinant enzymes can lead to early embryo fatality, which is not conducive to subsequent genetic function research." Ye Haifeng explained to science and technology daily reporters, on the other hand, long-term expression of Cre recombinant enzymes will also cause certain toxicity to cells, resulting in chromosomal rearfuration and cellular physiological function disorders.
, if the mice expressed this foreign Cre recombinant enzyme throughout its life cycle, it was either "short-lived" or "sick." When scientists use animal models to study the function of a gene, space is very limited and the effect may not be ideal, creating "pain points" in the application.In this published paper, the research team used the far red light regulation mammalian cell
expression control system developed by the team to stitch together four main components and complete the signal path construction from far red light to recombinant enzyme "switch".
", genetic recombination can be controlled not only in time but also in space, thus realizing the 'custom' needs of life science research. Ye Haifeng said, "For example, some genes systemic knock-out is fatal, it can not be sustained research, now if the use of light to control the fixed-point knock-out of genes, you can study the function of such key genes." After
design of the system with "smart line" added, Ye Haifeng team rigorously tested the whole program with the experiment of "3 steps". Ye Haifeng said that the testing of human embryonic kidney cells was not ideal at first, but by optimizing the initiation, particle size and other parameters, the optimal solution was finally obtained.
, the team tested them in mammalian cells and mice, respectively, and showed that the recombination system had higher recombination efficiency under far red light exposure. Live and liver imaging of mice showed higher fluorescent protein expression in the light group than in dark group mice.Zhujiazhuang's red lantern battle, relying on the recognition of the red light by the human eye. In the light control system of life science, it is a photosensitive protein called BphS that makes life activity "climb up" with light.
people have always wanted to control gene expression precisely from the outside, early hope through the chemical small molecules to achieve, the visual expression is "dot medicine" "add some material."
"I think small molecule control may not make much sense because chemical molecules lose local control as soon as they are added." Ye Haifeng believes that using light to control the expression of genes is different, can achieve which to say which.
to light, the first thought of the human eye in the retina protein, because the human eye is sensitive to light. Therefore, Ye Haifeng first studied photosensitive proteins in the human retina, but this protein is naturally sensitive to light at specific frequencies, and these frequencies have poor phototransmissive effects.
"In order to find useful photosensitive proteins, we have found in the literature 'needles in a haystack', from some literature reports found microorganisms, plant far red light response proteins, the range of available light is more extensive." Ye Haifeng said that later, some scholars from the microbiology identified BphS, is the light-sensitive protein we are now using.
based on some of the protein's functional properties, we transfer photosensitive proteins from red bacteria to mammalian systems so that they can still function," he said. Ye Haifeng says they have designed a number of strategies to assemble splicing parts through synthetic biology theory and assembling them into gene circuits with different functions.
, said the "light control" gene regulatory system could become more complex in the future. For example, blue light, red light, purple light to transmit different signals, and then achieve multi-color light control, while adding logic operations to control more complex cell behavior.