Uneaten vegetable protein textile steak is poured out.

Gao and her team set out to use Kobe beef's muscle cells to grow intact beef tissue.

There are three things that need to be done in the lab.

Cells were taken, genes were extracted, and cultured.

In today's biological world, the most difficult thing is to use animal cells to culture animal tissues, and most laboratories want to culture a certain tissue or organ of an animal, and generally take the embryonic cells of animals or the organs and tissues of young animals that have just been born for culture.

The reason for this choice is that these cells or tissues have a strong ability to divide and proliferate, and the culture success rate is high. In the case of fully differentiated cells, the cell differentiation potential is getting narrower and narrower, and the success rate of culture is very low.

However, the fully differentiated nucleus still retains all the original genetic material and has totipotency, but only when the conditions inside and outside the cell meet certain conditions, the cell totipotency can be expressed.

Going a little deeper, the genes in the cell report all the genetic information of the species to which the cell belongs, and if the internal and external conditions allow for pregnancy, the genes can be fully expressed, and even the species itself can be cultured.

Dolly the sheep, a cloned sheep cultured using mammary gland cells, illustrates this problem.

It's just that the experimental process of Dolly's kind is still a certain gap with the gene expression technology in the hands of Pangu Technology.

The process of producing Dolly the cloned sheep is a three-step process.

In the first step, the mammary gland cells are removed from the mammary gland of the ewe, and they are placed in a low-concentration nutrient culture medium, and the cells gradually stop dividing under the intervention of external conditions, and the cells produced by this process become donor cells.

In the second step, the unfertilized egg cell is collected from the body of another ewe, and the nucleus is removed, leaving a seedless egg cell, which is like leaving an empty house for the donor cell. The nucleated egg cell becomes the recipient cell.

In the third step, the donor cell and the recipient cell are fused by using electrical impulses, and finally the fusion cell is formed, which is similar to the egg cell.

In this way, the initial experimental procedure is complete. The following procedure is very simple, similar to culturing IVF, where the fused cells are placed in the uterus of a certain ewe, and finally they develop and grow, and are born.

The experiment of cloning Dolly sheep is one of the greatest experiments in the biological world, and it has also proved in practice that highly differentiated cells are still totipotent.

However, the experimental period is long, difficult and expensive, and its role in the research field is far greater than the role in practical application.

What Pangu Technology needs to do is perfect gene expression, no need to make donor cells, no need to make recipient cells, and make the genes in the nucleus fully expressed in the fastest and cheapest way, once again demonstrating the totipotency of the cell.

The purpose of Pangu Technology is to use this technology in food and medicine, so it is destined that the cycle of the experiment must be short and the cost must be low. If you follow the money-burning method of Dolly sheep, the laboratory will produce tens of thousands of pounds of meat, and it is better for farmers to raise them freely.

Gao Siqi carefully extracted the muscle cells of Kobe beef, and under the new experimental idea, the cell membrane of the muscle cells was broken, the gene sequence of the nucleus was lifted, and then the gene sequence was completely read through the gene reading instrument.

At this time, although the muscle cells have the totipotency of cells, they cannot meet the requirements of the laboratory in the regulation and expression of genes.

If myocytes are mitotic under the action of serum-like culture agents, the myocytes will continue to multiply just against the petri dish, a process similar to the continuous increase of myocytes in the body.

At this time, the product is still a muscle cell, but it is slow and the number of proliferations is effective. Normally, a group of healthy muscle cells, after a certain number of proliferations, will stop proliferating and then fall into decay en masse.

This is both the process of healthy cell death and the process of human aging.

(In terms of macroscopic cell death expression, it is related to cell telomeres, so I will not repeat it here.) ）

So what is the reason for the limited proliferation rate and proliferation of healthy cells? This is a topic that is being studied by molecular biology around the world, and it is also a topic that Pangu Technology is researching.

Pangu Technology already has a relatively complete answer, because in the regulation of gene expression, there is a mediation mechanism that controls the production rate and number of muscle cells.

The specific process is that every time a muscle cell proliferates, a negative charge in the gene will move down the number of times it multiplies, and at the same time it will move down in the gene fragment of the original muscle cell and the new individual that proliferates.

In the laboratory data, the number of shifts in the charge in the gene is strictly equal to the number of proliferations.

Then, when the negative charge is indicated to a certain point in the gene fragment, the entire gene expression changes dramatically.

Cessation of proliferation and senescence of cells, death ensues.

This is the experimental result of Pangu Science and Technology Life Science Laboratory when doing gene expression regulation.

Pangea's lab also did an experiment to stop the proliferation of cells and keep them in a fairly peaceful state.

However, the performance of the experimental samples also surprised Pangea Technology, as over time, the negative charge still has to move in the gene fragment, and even indicates a "death fragment" at a faster time, and then the cell dies in a peaceful state without proliferation.

Pangea's last indication to control the charge was that the cells survived longer, but still died.

This is the latest problem faced by Pangu Technology in the regulation of gene expression, although Pangu Technology can control the expression of genes, but cannot control the death of cells.

Back to the Kobe beef muscle experiment at Pangu Technology's Life Science Laboratory.

Since muscle cells are controlled by a negative charge, they cannot achieve the conditions for rapid proliferation, indefinite proliferation that the laboratory wants.

So what about the lab?

Gao Siqi's team was very clever in using an experimental approach.

First, the gene expression regulation laboratory is perfectly used here.

The conditions that control the directional proliferation of cells are eliminated, so that muscle cells do not proliferate slowly, as in the body of Kobe cows, and after a certain degree of proliferation, they will die.

So how can we make muscle cells proliferate quickly? or even proliferate wirelessly?

This question was put in front of Gao Siqi's team, and it also led to the second step of the experiment, learning about cancer cells.

This is also the point put forward by Xiao Ming.

"Learning cancer cells?" Gao Siqi was taken aback by Xiao Ming's idea.

Xiao Ming nodded and said, "Cancer cells proliferate quickly and can multiply indefinitely. We can inhibit the proliferation of cancer cells and make them die through gene expression regulation, and we can also learn the advantages of infinite proliferation and fast proliferation of cancer cells. ”