I can extract side effects - Chapter 650

c646 Cell competition is gone

Sanqing Headquarters, Stem Cell Laboratory.

Ding Mian sat in front of the inverted microscope, staring intently at the camera, carefully inspecting the cell suspension in the glass petri dish, completely ignoring the voices of inquiries coming from behind him.

“how is everything?”

“Is there any result?”

“Hey, you should say something.”

“Brother, please!”

“Just tell me a little bit, just a little bit.”

Huang Qin kept pacing back and forth behind him, with a painful and tangled expression on his face, and kept uttering pleading words from his mouth.

Finally, his harassment is showing results.

“Successful.” Ding Mian straightened up, stretched lazily, and said.

“Really?” Huang Qin stopped suddenly when he heard the words, turned around again, and rushed forward impatiently: “Tell me more.”

Ding Mian pointed to the microscope lens: “Look for yourself.”

Huang Qin put one eye in front of the camera, looked at it for a while, and said doubtfully.

“No, the cells inside are completely dead.”

Ding Mian waved his hand: “Look at the label, it’s a mixture of human and mouse stem cells, the kind that hasn’t been genetically modified.”

Only then did Huang Qin suddenly realize that he glanced at the glass petri dish on the experimental bench, squinted his eyes and looked for it for a while, then picked up a petri dish with the label “NF-kappa B-human mouse” and put it in the inverted microscope. superior.

This time, in just a few seconds, Huang Qin shouted excitedly.

“It’s amazing that the phenomenon of cell competition has disappeared.”

“Our work is in the right direction. Turning off the NFKB gene pathway is really useful.”

“These genetically modified human pluripotent stem cells could actually survive in a co-culture environment.”

“The survival rate has increased visibly with the naked eye!”

He turned around, his eyes sparkled, and he continued: “Does that mean that we can do in vivo experiments?”

Ding Mian nodded with a smile: “It can be done.”

Huang Qin instantly jumped up from the stool as if his butt was on fire.

“Then what are you waiting for, do it quickly.”

He was very excited at the moment, and felt that the door of the new world had opened a crack in front of him, as long as he squeezed hard, he would immediately enter the paradise he dreamed of.

After completing his Ph.D. defense at the end of last year, he returned to the company directly and joined Ding Mian in the research and development of xenotransplantation.

The two have done several months of experiments, and finally made a qualitative breakthrough today.

At the beginning, they tried to put pluripotent stem cells of different species such as large-mouse (rodent), human-monkey (primate), human-pig and cow together for co-culture.

Then the number of surviving cells per square centimeter was used as an index to judge the degree of apoptosis of the cells.

The answer is obvious.

From the third day, the gradual apoptosis of human pluripotent stem cells was observed in the culture dish, while the stem cells of other animals continued to grow.

On day 5, human pluripotent stem cells had only a handful of survivors.

This kind of apoptosis rate was really too fast, which immediately startled the two of them.

They immediately compared the surviving human pluripotent stem cells with the human pluripotent stem cells grown alone to see how the two were different.

What exactly is causing the cells to compete so fiercely?

After a round of gene sequencing, the analysis results showed that in the surviving human pluripotent stem cells, a signaling pathway called NF-kappa B was activated, which led to the rapid apoptosis of the cells.

Therefore, the next experiment is a matter of course.

The two intend to turn off this signaling pathway to test whether apoptosis can be inhibited in this way.

That’s how today’s scene came about.

The results were surprising. Human pluripotent stem cells that shut down the NFKB signaling pathway can survive in a co-culture environment.

In sharp contrast to previous experiments, the phenomenon of cell competition between different species disappeared.

Whether it’s human-mouse, human-pig, human-cow, the stem cells of both parties become warm and affectionate in the petri dish, as close as a family.

Of course, humans and monkeys belong to the same species, and the stem cell competitiveness between the two is similar. There is no obvious cell competition phenomenon, and it is mainly used in the experiment for comparison.

As for the other three species, due to the considerable evolutionary distance between species, there was originally fierce cell competition.

Stem cells from mice, pigs, and cattle that stand at the front of the evolutionary tree are more competitive and will quickly induce apoptosis of less competitive human stem cells.

Cell competition was originally a ubiquitous biological phenomenon, which is a normal result of natural evolution. It is mainly to prevent the invasion of foreign cells, which is very similar to the principle of the immune system.

However, under the blessing of human’s powerful genetic technology, this mechanism quickly disintegrated, creating a spectacle of harmonious coexistence of stem cells of heterogeneous organisms.

Seeing a breakthrough in the research, the two were ecstatic and immediately started a new round of in vivo animal experiments.

Pigs and cows are too big and have a long gestation period, so let’s start with human-mouse xenochimerism and test new research and development results.

Most of the preparation of chimeras uses microinjection, that is, injecting human pluripotent stem cells into early embryos of mice through micromanipulation.

Of course, the human pluripotent stem cells here are all genetically modified to turn off the gene signaling pathways that lead to apoptosis.

Five days later, there were 250 cells in the embryo, which successfully developed into a blastocyst.

In the next 15 days, the chance of chimerism was greatly improved, and the embryo was successfully formed in the mother’s body.

Seeing the fusion of human cells and mouse cells so smoothly, Huang Qin couldn’t help feeling a little worried.

“Well, if the human-mouse chimera is really born, there won’t be any ethical issues, right?”

Ding Mian asked back: “What ethical issues will there be?”

Huang Qin thought for a while, then hesitated and said: “Won’t human cells affect the reproductive cells of mice?”

Ding Mian gave him a strange look, and said casually: “You have to worry, it will be fine when the mouse is born and castrated.”

Huang Qin blushed, and distinguished: “I didn’t mean that, I mean, will human genes affect mice? For example, will there be genetic mutations in the brain or something?”

“Don’t countries like the Eagle Country have ethical requirements for human-animal chimeras? The requirement is that they cannot reproduce and cannot develop into a brain.”

“You also know that the biggest difference between humans and animals is the development of the brain. If the mouse brain develops again, is it really okay?”

After speaking, deep worry appeared on his face.

“Hey, so you are worried about this.” Ding Mian said with a smile: “It’s okay, it’s just a few human stem cells. Even if they are divided into mice, there won’t be too many human cells in each part.”

“As for the brain problem, that’s a ridiculous worry. Even if the human brain cells are in the brains of mice, they can only do what mice should do, and they won’t have human thoughts.”

“Because human beings are determined by the structure of the brain, not by individual cells.”

“You are a student of biology anyway, so you can’t even figure it out.”

Huang Qin was dazed: “But I’m still a little worried. Two days ago, my wife and I rewatched the classic film Rise of the Planet of the Apes. I feel that the plot development in it still has a certain scientific basis.”

Ding Mian said angrily: “You are a sequelae of watching movies, don’t think about it. They are gorillas. They are the same species as humans. They have a 99% genetic similarity and a well-developed brain. Of course there will be It might have changed.”

“You know, early Homo sapiens also had many competitors on Earth, such as Neanderthals.”

“Neanderthals are stronger than Homo sapiens, their brains are larger, and they share 99.7% of their DNA with Homo sapiens. Overall, they even have a slight advantage.”

“But they were eventually defeated by Homo sapiens.”

“Do you know why?”

Huang Qin said awkwardly: “I know, I have heard of it vaguely, it seems that a paper in “Science” mentioned this a few years ago.”

“That’s right,” Ding Mian hurriedly replied, “It’s good that you know.”

“The main reason is that a gene called TKTL1 in Homo sapiens stood out, and an important gene mutation occurred, resulting in the encoding of a new amino acid and the synthesis of a brand new protein in the body.”

“This protein, which is produced when the fetal brain is first developing, drives the formation of neuronal cells, resulting in denser, deeper and longer neurons in humans, especially in the neocortical region.”

“The neocortex is mainly involved in the higher functions of the brain, such as spatial cognition, sensory cognition, language, logical reasoning, motor commands, etc.”

“In this way, no matter how large the brain capacity of Neanderthals is, it is also a low-end version that can only perform some basic functions.”

“However, Homo sapiens is different. Relying on genetic mutations, language ability and collective functions have been unlocked since then. The group size can break through the upper limit of dozens of people, forming an organization of hundreds or even thousands of people, and gradually becoming the overlord of the earth. ”

“A small genetic mutation, a change in the structure of an amino acid, and the formation of a new protein have completely changed the fate of the Homo sapiens race and created a great civilization.”

Ding Mian couldn’t help sighing: “Nature is so magical, and the birth process of life and civilization is so incredible. Every time I think about it, I am filled with emotion.”

Immediately afterwards, he looked solemn and said.

“Because of this, if similar gene mutations occur in gorillas or apes, it is very likely that the brain will develop again and catch up with human intelligence.”

“That’s why the ethics committee strictly restricts our genetic modification of primates. As long as we don’t mess around, there should be no problems.”

“As for other animals, their genomes are too far from those of humans to affect their brains, so don’t worry.”

However, these words did not completely dispel the worry in Huang Qin’s eyes.

But he did not continue this topic, but nodded, agreeing with Ding Mian’s conclusion.

“I understand that science fiction movies are fictional and belong to artistic creation.”

“As long as we don’t do genetic experiments on primates, and don’t give distant relatives a chance to overtake, the plot in the movie won’t happen.”

“That’s why we insist on doing pig organ transplants.”

Ding Mian waved his hand resolutely and made a knife-slashing movement, revealing a murderous aura.

“That’s right, even if you do it, you can’t allow the embryo to survive for a month. You must completely kill the threat in the womb.”

At this moment, in the cage behind him, the mother mouse suddenly let out a shrill squeak, interrupting the conversation between the two.

Ding Mian trembled all over, slowly turned his head to look over, and opened his mouth in surprise: “Ah, it’s about to give birth.”

Huang Qin hurriedly said: “Go and see, I don’t know if this chimera can survive.”

The two hurried over and looked curiously at the few pink and white meat balls emerging from the mother mouse’s body.

“It’s up to fate, we can’t help you with breastfeeding.” Ding Mian shrugged and said.

Huang Qin counted the meatballs and found five of them. His expression changed suddenly: “They all survived, and none of them died. The survival rate is 100%. It’s really terrifying.”

Another question flashed through his mind like lightning: “Tell me, when will we euthanize them.”

“What? Are you still thinking about this stupid thing?” Ding Mian was stunned for a moment, then realized, and said in surprise: “This chimera doesn’t look like it will die.”

“Are you thinking too much? Mice only live for one or two years, and this kind of chimera can’t live long. Are you afraid that it will live too long?”

Huang Qin stared at the little things lying on the belly of the mother mouse and drinking milk with their eyes closed, feeling a little uneasy.

“I’m not worried. The main thing is to go through the process. Originally, this kind of chimera will also be destroyed. I will finish it sooner and feel at ease.”

“Otherwise, thinking about the cells of Lao Tzu in this mouse always makes me feel creepy.”

Ding Mian closed his eyes, took a deep breath, opened his eyes again, and said calmly.

“Okay, then follow the procedure and destroy it after four weeks. I don’t know if these little guys can live until then.”

“Anyway, I won’t use your cells next time. I’ll use my own, so you won’t feel weird anymore.”

Huang Qin smiled awkwardly, and hurriedly explained: “Listen to me, I don’t mean that, I just have obsessive-compulsive disorder. Didn’t I do animal experiments before? I haven’t used my own cells, so I’m not used to it.”

Ding Mian said speechlessly: “You are purely Mr. Ye and a good dragon. Who told me at the beginning that such a big project requires a sense of participation, so you need to use your cells?”

Huang Qin scratched his head, feeling a little ashamed, and lowered his voice.

“This person is like this. When I haven’t seen it before, I always want to try it. When I really try it, I feel unbearable, haha.”

But the next few words he said made Ding Mian want to go berserk.

“Xiao Ding, don’t you think it’s strange that you use your own cells for the human-pig chimera?”

“Think about it, when the pig has your cells in it, can you stand it just looking at you in the cage?”

“The genetic similarity between pigs and humans is also very high, plus your own human genes, tsk tsk, I dare not imagine this picture.”

“Shut up!” Ding Mian spit out two words expressionlessly.

Huang Qin opened his eyes wide in surprise: “Xiao Ding, isn’t it, why are you still angry? I’ll just say that casually.”

“You!” Ding Mian’s emotional management finally got out of control, he turned around and left angrily.