I’m just curious about the science, and potential. I ask that we keep morals and ethics out of this one, TIA.
So we’ve mapped the human genome now, many times over, and we can genetically engineer corn. Where are we in terms of human genetic engineering?
I mean, how far along are we, and what is the end game?
I envision a day where parents supplant their own DNA at will.
“I’ll take 40 moles of that ATCG, take out all the laziness traits. Give this one a right-brain creative mind with a penchant for music, #225.7 voice (cloned from Elton John, Paul McCartney, and Freddy Mercury), finger dexterity. Oh yeah a big dick.”
While the development of CRISPR/Cas9 gene editing has been revolutionary in research and offers great opportunities to treat genetic maladies and provide more effective vaccines, targeted cancer treatments, and fighting antibiotic-resistant bacteria, it is not the biomagical potion that many people seem to believe it is. It’s most useful ability may be not in actually editing the genome but selectively turning on and off gene expression through epigenetic modification (methylation interference), preventing ‘bad’ genes from being expressed at critical developments, or forcing the activation of genes that provide a crucial function but aren’t operating correctly.
Part of the problem with genetic editing is that we only have a cursory understanding of what most of the human genome does, and so the results of any particular edit may have unexpected consequences or affect the expression of other genes. For instance, genetic modification to improve intelligence may have other unintended consequences such as creating neurochemical imbalances that could make a patient schizophrenic or cause malformations in affective regulartory systems. Of course, you won’t be able to determine this until you modify a zygote and then let it gestate and be born and then let it grow into an adult, which means assessing effects on humans will be a slow processes.
Many of the capabilities imagined by would-be transhumanists have complex physiological interactions; even though you could express the legacy genes that exist to make gills, it is not possible for a warm-blooded mammal to extract enough dissolved air from the water to sustain themselves, hence why aquatic mammals such as cetaceans, pinnipeds, and sea otters have developed adaptations for living in the surface and extracting maximum oxygen from a lung’s volume of air rather than re-evolving the gill. Actually producing novel capabilities would require so much system-level reengineering of human physiology I think we’re still a long way off from making radical changes to the human form or even selecting for specific capabilities with a high degree of assurance, notwithstanding the ethical issues.
Once place where control of gene expression and repair of the genes would help is in space medicine and physiology. Right now, we have considerable evidence from the six-month to year-long stays of a few astronauts on the ISS that long duration (or even for durations of a few months) has a number of deleterious effects both due to the freefall environment and high energy cosmic radiation. While it would be possible in theory to provide simulated gravity via centrifugal mechanism and protection from radiation, the increases in mission requirements of both inert “payload” mass and propellant rapidly become prohibitive even for a crewed mission to Mars, much less the asteroids or outer planets. The ability to directly repair or prophylactically protect the genome from damage and control expression to prevent physical deterioration would go a long way to making long duration human spaceflight viable.
Since the OP has been on the Dope since 2001 and only has 200 posts, I figured I had to share what I could.
My son is in college studying this stuff - he did an internship at a genetics lab in High School and is now getting a double major in statistical biology and business.
Bottom line: CRISPR/cas9 is like Gutenberg’s printing press. It takes something that had been complex, pricey and done by hand, and introduces a method that is much more simple, less expensive (per splice, if you will) and done with a replicate-able process.
**Stranger **shared some of the things they can do. But what will be interesting is what Humans will do with this stuff when they can get a CRISPR kit to do it at home!
CRISPR/cas9 is like Gutenberg’s printing press and you know only the rough definitions of a few words and some general grammatical rules and you get the idea that you can rewrite a novel that is almost but not quite jibberish to you.
I went blind before I got 10% down into the Wiki of CRSPR, but I made it through your explanation, so thank you for an excellent dumbing down of that for me.
There are certain things that could be done right now. There are certain known genetic diseases that result from a change of a single nucleotide. I think Tay-Sachs, sickle cell and other specific defects could be corrected now. But to be meaningful, the change has to be in the germ cells and that is currently a no-no. Myself, I cannot see a single objection for these genetic diseases.
But things like intelligence are simply not understood at all at a genetic level. Even hair and eye color are much more complicated than used to be thought. Two blue-green eyed parents can have a brown eyed child. My wife and I do. We are not in a position to do these more complex things, not nearly.
The “potential” is fabulous. Right now, Nature has its own form of genetic engineering. It’s called, “Natural Selection”. Genetic traits that allow an organism to survive and flourish are carried on while genetic traits that are damaging are eliminated when an organism fails to survive. Unfortunately, not only is the process a very long and arduous one, it is faulted because, in many instances, an organism can reproduce before it succumbs to a genetic deficiency. Thus, the genetic deficiency is carried on.
With human genetic engineering, however, we not only accelerate the process many times over, we can eliminate damaging genes that Natural Selection cannot. Evolution of the human species can happen in a lifetime, not over a million years.
I know I’m misunderstanding a lot but please help;
Every description I’ve heard of DNA modification, like CRISPR, starts off talking about editing the DNA of one cell. But we’ve got DNA in every cell in the body. How are edits to be implemented, if not across the whole body, at least in the area they’re trying to effect? Say you’re implementing a DNA edit to repair a gene known to cause lung cancer - how is that edit made across the lungs (or maybe farther) ?
With great difficulty and rare success. These techniques tend to be done on a test tube (or petri dish) full of “loose” cells and scientists are thrilled when 1 percent of the cells integrate the change correctly. Thinking of correctly making targeted gene modifications in every cell of an adult (or even every cell of a specific tissue type) is still science fiction, will continue to be science fiction for the foreseeable future, and possibly will remain science fiction forever. The proper time to correct someone’s genome is while they are a zygote.
Lungs would be one of the easier tissues to treat, repurpose a respiratory virus and control the immune reaction.
One main issue would be how long it could take to see side effects. If making your kid a tall genius gives him a 10x risk of developing cancer, they might die in their 40s, or develop dementia at 50…it’s a long time to wait to determine side effects…ethics committees wouldn’t sign off.
Fixing germ cells to do ivf could allow people with high risk genes safely have their own kids.
You need a country with no ethical restrictions to test everything, which I suspect means at some point and bunch of 10’ tall, bulletproof north Koreans will charge across the DMZ in 18 years or so
We’ve Sequenced the Human genome! CRISPR/Cas9 allows us to edit genes! Exciting stuff, hooray science! A revolution of genetically perfected humanity is surely just around the corner! Right? Just around the corner? Surely?
No. Sorry, but as cool as it would be to genetically engineer mutant atomic super men, we’re not there yet.
You see, we (by “we” I mean scientist who study this stuff) are ignorant of a LOT of stuff. As anyone who watches Lindybeige knows “we can’t read the gattaca.” We’re closing in on eliminating genetically inherited illnesses, but a designer child is REALLY far off. Hell, a designer flower isn’t even in the cards for now. I have no doubt that we’ll get there eventually, but it’s going to take a lot time and effort. As my middle school science teacher was fond of saying, “science is hard.”
A major limitation is that our standards of success for human modifications are naturally much, much higher than for non-human organisms. Human engineering of any type will always lag behind because we won’t tolerate the kinds of failure rate or side effects with humans that we would with an engineered corn plant or something.
Actually there’s a bigger problem; anything that makes a good organ for exchanging oxygen also makes a good heat exchanger, and water absorbs heat far better than air does. Even if there was enough oxygen or if the mammal just used it to supplement stored oxygen, the animal would die of hypothermia* anyway.*
Another issue is that it* always* throws the baby out with the bathwater. Natural selection doesn’t clip out one defective gene, it discards the entire genome of the “loser”, and quite likely kills the “losing” organism in the process.
Also, natural selection “cares” only about what succeeds in getting the gene into the next generation. Not what’s good for the organism the gene is in, and not for what happens in the generation after that; it has no foresight.
