Kunming City, Suzhou University Sanqing Branch.
Jingle bell bell~
At eight o'clock in the morning, the school bell rang on time.
Huang Qin stood at the door, devouring the last bun in his hand, throwing the plastic bag into the trash can, and then walked into the classroom to the sound of the bell.
I randomly found a corner, took out a thick textbook, and listened to the class carefully.
It has been almost a year since he returned to class, and he has long been accustomed to this busy life of coming and going in the wind, between company, home and school.
I come to school every morning for two classes, have a meal in the cafeteria at noon, rush back to the company to work in the afternoon, go home in the evening to read literature, keep in touch with my tutors and classmates, and fall asleep at 12 o'clock. After going back and forth, I actually fell in love with it. This incredibly fulfilling feeling.
Today was the professional class "Cell Engineering Technology". The teacher was frothing at the mouth while speaking on the podium. The classmates were drowsy below, but he was the only one who felt energetic after listening to it.
Especially when the teacher talked about the chapter "Animal Cell Engineering", Huang Qin became happy as soon as he heard it.
"Haha, animal cell culture, animal somatic cell nuclear transfer technology and animal cloning, animal cell fusion."
"I am so familiar with this course that I can almost teach on stage."
"Teacher, this ppt hasn't been updated in years, and it's still talking about the breeding process of Dolly the cloned sheep."
"I have to score 100 points in the final exam again. How embarrassing."
When Huang Qin thought of this, he couldn't help scratching his head and smiling innocently.
He is studying for a master's degree and a Ph.D. in two years and three years for a doctorate. Basically, all courses are arranged in the first year of graduate school. Starting from the second year of graduate school, he has to formally choose a topic and warm up for scientific research.
Several required major courses, such as "Advanced Biochemistry", "Cell Biology", "Molecular Biology", and this "Cell Engineering Technology", are all contents that he is familiar with and uses in his daily work. .
So if nothing else goes wrong, you can basically get full marks on the test.
What gave him a headache was Ma Zhe. In a public course like academic ethics, he had no time to review. He could only take notes and memorize by rote before the exam, and narrowly passed the test with a score of just over 60 points.
As for English, he has been working with Williams for several years and has long been trained. Whether it is graduate English or professional English, it is no problem to get 80 or 90% in the test.
As for those elective courses, animal model applications, commonly used experimental techniques, molecular pharmacology, genomics research, protein engineering, electron microscopy observation and living cell detection technology, etc.
He knows everything very well, and he can't be more familiar with it. It's like buying vegetables at the market. He can answer the questions with his eyes closed.
The operation was as fierce as a tiger. After the test, I got 99.
In the remaining literature discussion class, he revised a reading note he had written before and submitted it, which attracted praise from the teacher.
In short, after these classes, he was shocked to find that everything was incredibly simple. It was easier to get high marks in exams than to eat and drink.
And he also completely completed the magnificent transformation from a scumbag to a top student, and healed his long-term fear of exams.
Otherwise, school life can be considered relaxing and pleasant, a break from the rigid routine of the laboratory.
The morning's classes passed by in a blink of an eye. Huang Qin ran to the cafeteria at the speed of light, packed two lunch boxes, and ran to the laboratory happily.
"Teacher, I brought you a meal, including your favorite chicken drumsticks."
Huang Qin opened the lunch box, revealing a shiny big chicken drumstick. He knew that teachers usually eat late, so he brought him a portion.
Du Biao raised his head and looked at him with complicated eyes: "Huang Qin, thank you for your hard work."
This student really has nothing to say. Although he sometimes speaks too straightforwardly, he is diligent, studious, cheerful and enthusiastic, and can also recruit people into the group. With such a capable student, every instructor can wake up from his dream in the middle of the night with a smile.
He almost woke up laughing in the middle of the night last night.
Huang Qin held the chicken legs between his legs and gnawed until his mouth was full of oil. He did not forget to remind the teacher.
"Teacher, please eat quickly, the food is almost cold."
Du Biao had no choice but to eat together, but he had something on his mind, and his favorite chicken legs were tasteless in his mouth.
After finally finishing eating, he wiped his mouth and couldn't wait in his heart, but he pretended to be calm and asked as he asked.
"Xiao Huang, do you have any thoughts or ideas on the topic you mentioned? Do you want us to discuss it together?"
Huang Qin nodded and his expression became serious.
"Teacher, my idea is this, mainly divided into two steps."
"The first step is to address some of the issues surrounding pigs themselves as a source of xenogeneic organs."
"There is a consensus in the transplant community that pigs are an ideal source of human organs. However, problems such as viral infection, immune rejection, and abnormal coagulation function need to be solved before they can be considered a qualified source."
"Viral infections are easy to solve. We can raise them in a sterile environment and screen donors to prevent hepatitis virus, cytomegalovirus, lymphoid herpes virus and other pathogens from infecting the recipient."
"In addition, gene editing technology can also knock out endogenous retroviruses in pigs and reduce the risk of infection after entering the human body. However, these pig organs have not yet been implanted into the human body, and the potential risks require further clinical verification."
"As for immune rejection, compared with allogeneic organ transplantation, the immune rejection reaction of xenogeneic organ transplantation is more serious and more complex. However, we can knock out specific antigen genes through gene editing and transfer into humanized genes, which can be effective Inhibit the occurrence of transplant rejection."
"The academic community has discovered 29 related immune genes, of which 21 foreign genes need to be inserted and 8 endogenous genes need to be broken through or knocked out."
"Our first step in research is to figure out different gene combinations to see which gene combination has the best effect on which organ transplantation."
"It sounds like a lot of work, but many genes already have clear research results. We only need to conduct permutation and combination studies and then verify the results."
"As for the verification method, you can choose non-human primates, transplant the genetically modified pig internal organs into macaques or baboons, observe their survival time, and then test the organ function, coagulation parameters, and receptor activity By taking the test, we can know the result of the transplanted organ.”
The more Du Biao listened, the more frightened he became. He was worthy of being a leading student who could guide his mentor. Not only could he choose his own topics, but he also had in-depth and feasible thinking on the solutions to the topics.
He wanted to express some opinions, but he didn't know what to say when he opened his mouth. He hesitated for a while before slowly spitting out two words.
"very good."
After thinking for a while, he added: "Clear thinking, clear goals, great job!"
Huang Qin smiled honestly: "Thank you for the compliment, teacher. The verification of gene arrangement and combination is relatively simple but very tedious work. You may need help from teachers and classmates."
"After all, there are 29 genes, and it is not ruled out that new influencing genes will be discovered during the research process."
Du Biao muttered: "You are very thoughtful. If you want to exhaust all the permutations and combinations of these dozens of genes, the number of experiments that need to be carried out will be extremely huge. However, there must be some key genes. We only need to seize a few A key gene can produce results."
"So the workload is actually not that big. We can use some mathematical methods, such as exhaustive methods, to screen. Then through some carefully designed experiments, we can find a few key genes."
Having said this, he showed a confident smile: "Your tutor and I were still one of the best in mathematics back then. There will definitely be no problem with my research and analysis in this area."
Huang Qin nodded repeatedly: "That's great. The teacher said that, and I feel relieved."
"As for the algorithm and verification, teacher, you don't have to worry. Sanqing has powerful artificial intelligence. As long as you record all the experimental data, I will take the data back and run the simulation, and the analysis results should be available soon."
The smile on Du Biao's face suddenly fell. He thought of Sanqing's AI diagnosis and his heart sank.
Huang Qin saw that the teacher's face was not good, so he quickly comforted him: "No matter how strong the AI analysis and simulation capabilities are, without teachers and classmates working hard to do experiments, there would be no data to analyze. Haha."
"That's right." Du Biao's face returned to normal and he said slowly.
"By the way, you just said that the project is divided into two steps. You mentioned the first step, but what about the subsequent plan?"
Huang Qin cleared his throat, returned to the topic, and continued.
"The second step is related to stem cell research and embryonic development."
"You should be well aware that any animal's development from a fertilized egg to an embryo must not only receive instructions from ancestral DNA, but also be affected by extracellular tissues."
"Cell cultures in vitro cannot simulate the complex interactions between cells and cells and between cells and tissues in the body that are necessary for organ formation."
"Just like whether a person can become a talent, in addition to his or her IQ, family education is also very important."
"No matter how smart a child is, if he has a tragic childhood, it will be difficult for him not to grow into a crooked-necked tree."
“Getting back to the subject, our ultimate goal in studying pigs is to use them to grow human organs.”
"Originally, there is isolation between different species. It is impossible for pigs to grow human organs."
"But fortunately, all of our mammals come from the same ancestor. Although they are distantly related, they all have the same origin. They all evolved from single-celled organisms and share the same underlying cell operating mechanism. "
"This certainly presents a huge opportunity for xenotransplantation."
"As long as we master the secret, we can make stem cells obey our instructions and automatically grow the organs we want."
"What we should do is to modify the host animal and artificially create a niche for the required organs."
"As long as the host embryo is modified so that it loses the ability to form a certain organ, a vacancy can be left in its original position."
"Then human stem cells are injected into the host's embryo, which can quickly fill the gap and automatically grow organs that would not otherwise grow."
"The whole process is quite amazing, one of the greatest miracles of nature."
"It's like you engineered a mouse and knocked out a key gene so that it couldn't produce the white blood cells of the immune system, and then you injected stem cells from normal mice into it."
"These stem cells injected into the embryo have no specific fate at the beginning. They have the potential to develop into any type of tissue, but they are confused and have no idea what they should do."
"As the embryo develops, the original cells in the embryo seem to be saying, it's time to produce immune cells, wait a minute, we don't have the genes to produce white blood cells, ah, look, these outsiders do, let's just let them take on this task."
"What's even more amazing is that these outsiders are really obedient. After hearing the instructions, they actually develop into white blood cells."
"It can be seen that during embryonic development, if they have any defects, they will actively fill a vacant tissue niche with suitable cells from other organisms."
"This process can be induced by artificially creating a niche."
"The same approach applies to the pancreas, kidneys, liver, and other organs."
"Cross-species applications are equally valid if you do a cross-species experiment between rats and mice."
"Although rats do not have a gallbladder, the cells still have the ability to form gallbladder tissue. If conditions permit, the mouse embryo can send a signal that it is time to grow a gallbladder, thus unlocking this ability."
"This ability comes from the common evolutionary ancestor of rats and mice. This ancestor had a gallbladder, but the rat's gallbladder disappeared during the process of evolution. However, the cells of rats still remember the development instructions of the gallbladder. , like preserving the memory of their evolutionary history.”
"But this method is not that simple in humans and pigs."
"On the one hand, the experiment lasts longer. The gestation period of pigs is 3 months, while that of mice is only 3 weeks."
"On the other hand, humans and pigs are much more distantly related evolutionarily than mice and rats."
"Pigs can create niches for organs in their bodies. After transplanting embryonic stem cells from another pig, pig embryos lacking a key gene for pancreatic development were indeed able to grow a pancreas."
"But when human induced pluripotent stem cells are introduced into blastocyst-stage pig embryos, the survival rate of these stem cells is very low. Only a small number of cells can survive and develop into muscle and precursor cells of some organs.
"Similarly, human induced pluripotent stem cells can also survive in bovine embryos, but the survival rate is also not high."
At this point, Du Biao excitedly interjected: "I know this reason. I have read a paper that stem cells of species that are too different will compete with each other and kill each other."
"This kind of evolutionary difference between species can form an effective developmental barrier to maintain the isolation between species and prevent the growth of strange creatures."
"Bah bang bang!" Huang Qin clapped vigorously: "Teacher is really knowledgeable and talented."
He changed the topic and said: "I have also read this paper. It seems to be a paper in "Nature" two years ago."
"The study found that as long as the activation of the NFKB signaling pathway in human IPS stem cells is inhibited, competition between cells and apoptosis can be inhibited, and the survival rate of human-mouse chimeric embryos can be improved."
"There are different levels of competitiveness between different species. Between rats and mice, humans and monkeys, the competitiveness of stem cells is similar, so there will be no cell competition."
"However, the relative competitiveness of stem cells between humans and pigs, cows, and mice is different, which will lead to the occurrence of cell war. The more competitive cells directly induce the apoptosis of the weaker ones. Which one is stronger depends on the relationship between the two. evolutionary distance.”
"So as long as we knock out the relevant genes in pigs, we can make pigs grow human organs."
"This path is very clear and promising, but no one has yet found the exit and produced the final results."
"Teacher!" Huang Qin held Du Biao's hands tightly and said excitedly.
"The future is bright, just seize the day and live up to your time!"
"As long as you win this jewel in the crown of science, teacher, your outstanding talent will be safe!"
Du Biao held the student's hand with his backhand. He was also very excited and said in a trembling voice.
"Go up to the sky to catch the moon, and go down to the five oceans to catch turtles, all at the snap of a finger!"
"Whether a teacher can become an outstanding youth depends entirely on your training!"
(End of chapter)
