Mutant sterility delayed by genome doubling?

Insane wanderer

First time out of the vault
If the FEV virus "repairs" its host's gametes by restoring their chromosome complement, would sterility necessarily befall the parental generation? Wouldn't the F1-generation simply become tetraploid? In fact, autopolyploidy would probably naturally enhance the FEV effect by making the offspring larger due to the increase in cell size (caused by the repression of certain proteins which facilitate the cell's movement through the G1 phase of mitosis, when growth occurs) and also more fit due to the increased expression of all the host's genes.

Sure, the four homologous quadrivalent chromosomes forming during prophase in meiotic cells of F1-generation individuals would be less stable than bivalent ones and thus more prone to fertility-reducing segregation errors. It's a short-term process so the mutants are destined to die out anyway but perhaps not after just one generation, as the game tells you.

Or maybe I'm mistaken. Thoughts?
 
Interesting speculation, but here is a question i put to you, say you were a mutant who had retained his intellect, how would you go about increasing mutant fertility? That is the question that interests me greatly.



Cheers Thorgrimm
 
Thorgrimm said:
Interesting speculation, but here is a question i put to you, say you were a mutant who had retained his intellect, how would you go about increasing mutant fertility? That is the question that interests me greatly.
Did you just ask him to pretend to be a supermutant? Oooh, I know - let's turn this into a roleplaying thread! :)
 
Insane wanderer said:
If the FEV virus "repairs" its host's gametes by restoring their chromosome complement, would sterility necessarily befall the parental generation? Wouldn't the F1-generation simply become tetraploid? In fact, autopolyploidy would probably naturally enhance the FEV effect by making the offspring larger due to the increase in cell size (caused by the repression of certain proteins which facilitate the cell's movement through the G1 phase of mitosis, when growth occurs) and also more fit due to the increased expression of all the host's genes.

Sure, the four homologous quadrivalent chromosomes forming during prophase in meiotic cells of F1-generation individuals would be less stable than bivalent ones and thus more prone to fertility-reducing segregation errors. It's a short-term process so the mutants are destined to die out anyway but perhaps not after just one generation, as the game tells you.

Or maybe I'm mistaken. Thoughts?
If you're expecting answers and thoughts from anyone, you're not using the correct words. I'm not a biologist, so I don't know half of the terms yhou're using, and I'm too lazy to go look them up. I don't think there are that many people around here that could follow you, and even fewer who are going to post their thoughts here. Stepping out of the Biologist Jargon would help a lot, though.
 
Sounds like some kidde just aced his bio vocab exam and decided to post something.


There is not true test to know weather homo-sapen would survive mutated in such a way, muchless be capable of going to the F1 or beyond generations other than truly initating such a mutation.
 
Actually we had this discussion before, in 2002 or so. I`m curious to see what comes out of it.
 
Sorry, I'm used to being around people who are familiar with this stuff. One sometimes doesn't think about that most people aren't.

To start from the beginning, diploid organisms such as we have two sets of chromosomes, one from each parent. Their germ cells (gametes) are haploid, meaning they've lost one set. When fertilization occurs, the diploidy is restored and a new individual takes shape, with a full amount of 46 chromosomes in our case, 23 from each parent.

Meiosis is the production of germ cells. One of its phases is the prophase(1), in which homologous (parentally connected) chromosomes pair up, forming so-called bivalents and swap genetic info through a process called recombination. This exchange makes sure that our chromosomes aren't identical copies of our parents'. Following this, they segregate from each other and end up in separate gametes.

Occasionally accidents happen and the bivalent's separation doesn't go through, creating a gamete with one chromosome more or less than it should have, resulting in various genetic disorders. If this were to happen to all chromosomes, a whole new set would be created. A normal, haploid germ cell fertilized by one of these would yield a triploid organism, assuming that the individual survives. If both gametes were diploid, the offspring would be tetraploid. The condition is called polyploidy and is infrequent in many animal species but quite common in plants.

Just to clear it up, someone exposed to FEV would belong to the parental(P) generation, while its potential offspring would be F1.


Sounds like some kidde just aced his bio vocab exam and decided to post something.


There is not true test to know weather homo-sapen would survive mutated in such a way, muchless be capable of going to the F1 or beyond generations other than truly initating such a mutation.

Work on your spelling, lest you give the impression of being a kiddie yourself.
 
Meh, Ive been misspeiling here for over a year :p



And I meant the first part in a complementry way, the second part was refering to that we dont truly know for fact, just theroy, if humans would survive such a mutation.

While an experiment could be done to test the theroy, Im sure that we lack the nessacary tech and it would violate scientefic ethics, as it would spell certain death/disfigurment for the test sujects.



Hmmmm......... maybe the US should annex kanada to get test volunteres.............
 
His point was not one of testing, PsychoSniper, but one of speculation. This is theory, not practice. Perhaps reading posts thoroughly and thinking before you post would help prevent these things.

Also, if that was a compliment, then you really need to work on your people skills.

Insane wanderer:
Thanks, that really helped, and it freshened up some of my lingering biologist jargon as well.
So, if I'm correct, you're suggesting that the sterilization, if taking place, would've taken place due to the fact that the production of mutants of the F1 generation is inherently instable. but that mutants themselves (the ones originally exposed to FEV) would not be sterile due to the FEV reproduction.
Now, I'm not a biologist, so this may be incorrect or sound a little fuzzy, but I recall that FEV had been mutated due to radiation. Would this not effect the sterility of mutants? As in: the sterility isn't necessarily caused by the way in which FEV operates, but because of what it does.

It could, in any case, not have anything to do with radiation damage to DNA in combination with FEV, since the 'smart' mutants were sterile as well, and they were the ones with very little radiation exposure.
 
It was always my impression that the chromasomes in the reproductave organs (sperm/eggs) was simply damaged by the FEV, rendering it inefective.
 
Based on what the Glow computer says, they're not damaged per se but replicated, resulting in aneuploidy: wrong amount of chromosomes.

The concept of a virus "healing" its host is clever, since it ensures its own survival in the process. It kind of makes sense if FEV happens to be a provirus, meaning that it integrates itself into the host genome, instead of taking over a cell's replication machinery outright and eventually causing it to burst, prompting the immune defense to react.

As for increasing mutant fertility, I guess the most straightforward approach for giving them the chance to procreate would be to isolate two germ cells, extract one set of chromosomes from each and then do an in vitro fertilization, i.e. in a test tube.

This is pure conjecture but another way to go about it could be to utilize something called restriction enzymes. R-enzymes are a bacterial defense mechanism against viruses. They degrade viral DNA by recognizing specific sequences and cutting it there. I'm not sure, but it could be conceivable that strains of bacteria have developed in the Fallout world with the right type of r-enzyme against FEV. If the proper gene were identified, isolated and inserted into the appropiate stem cell in a foetus, maybe the virus could be neutralized.

I know this is just circumventing the problem and hell knows what the effects would be.
 
Sander said:
Now, I'm not a biologist, so this may be incorrect or sound a little fuzzy, but I recall that FEV had been mutated due to radiation. Would this not effect the sterility of mutants? As in: the sterility isn't necessarily caused by the way in which FEV operates, but because of what it does.

Right; while explaining the flaw in his plan to the Master, I recall one of the dialogue options being something like: "Maybe the virus didn't turn people sterile once but it does now". This is an indication of what you're saying but if FEV always had that healing effect, I don't get how the virus could tell the difference between gametes and somatic cells before it was mutated.

On the topic of healing, there's the matter of accelerated mitosis - cell division - being more than just DNA replication. Maybe I'm digging deeper into the science than the developers intented me to?
 
Insane wanderer said:
Maybe I'm digging deeper into the science than the developers intented me to?
I think you've hit the nail on the head there. Having the mutants be sterile was ironic, in that the Master was turning people into mutants to improve and save the human race by adapting them to their current environment, instead it turns out he's doomed them to an evolutionary dead end. I doubt the designers put any more thought into the science of it than how do we have a non-violent way to end the Master?
 
Ratty said:
Thorgrimm said:
Interesting speculation, but here is a question i put to you, say you were a mutant who had retained his intellect, how would you go about increasing mutant fertility? That is the question that interests me greatly.
Did you just ask him to pretend to be a supermutant? Oooh, I know - let's turn this into a roleplaying thread! :)

Ah, it is good to see that NMA is still populated with vermin, who only come out of the dark to make fun of their betters. :roll: Another example of the 'superior intellect' you show Ratty, ratlike stupidity. As far as i can tell from your idiocy, you have not contributed anything but trolling stupidly on the Fallout boards. When you are able to rub two brain cells together and create something besides trollbait, then let me know. As i would enjoy greatly the sight of true intellect, not the parroting of it you show here. Get lost boy and don't bother your betters.


Thorgrimm
 
In his defence, Ratty actualy shows a bit more maturity than that.

And he meant it as a joke, too, or so Id wager.


EDIT- I mean he usualy shows more maturity than that. Its certain others who do what you accuse him of usualy.
 
Ah, it is good to see that NMA is still populated with vermin, who only come out of the dark to make fun of their betters. Rolling Eyes Another example of the 'superior intellect' you show Ratty, ratlike stupidity. As far as i can tell from your idiocy, you have not contributed anything but trolling stupidly on the Fallout boards. When you are able to rub two brain cells together and create something besides trollbait, then let me know. As i would enjoy greatly the sight of true intellect, not the parroting of it you show here. Get lost boy and don't bother your betters.
And this is not a troll, then? Get lost, boy, and don't bother your betters.

Ratty just makes a bunch of humorous remarks, usually, but he has a lot to add when he does get into serious conversations. Don't flame someone before you know any facts.

Right; while explaining the flaw in his plan to the Master, I recall one of the dialogue options being something like: "Maybe the virus didn't turn people sterile once but it does now". This is an indication of what you're saying but if FEV always had that healing effect, I don't get how the virus could tell the difference between gametes and somatic cells before it was mutated.
Perhaps it didn't, but a secondary mutating effect somehow appeared that does affect all cells, but has the effect of producting sterility as well. Could this be possible?
 
Methinks we are delving way too deep into genetics here. Keep in mind that Fallout was designed by game developers, not by people with PhD in biology. From what's said in the game we can draw that FEV is a retrovirus that upgrades infected cells to quad-helix structure and possibly repairs inherent genetic flaws (otherwise the tetraploidy would likely lead to accumulation of negative or even lethal mutations). I believe it is also said that FEV is capable of fixing only cells that have exactly 46 chromosomes, so gametes (and possibly aneuploid somatic cells) are destroyed rather than evolved. Insane Wanderer stated that the Glow computer says reproductive cells aren't destroyed but replicated, but I don't recall reading that anywhere - can someone with a savegame near Glow check that? If my memory is correct, then it would explain a lot of things, including why the parental generation is rendered sterile. If not, it creates a whole load of new questions. If a) FEV doesn't destroy gametes but makes them diploid, and b) infected organism gains improved regenerational abilities (thus becoming virtually immune to genetic degradation) - then wouldn't the fertilized egg retain the same qualities and be capable of repairing errors that were inflicted during meiosis I? I speculate that perhaps the parent's antibodies - being apparently powerful enough to repell virtually any "foreign" cell, from infectious bacteria to organism's own cells that became altered beyond repair (ever heard of a supermutant with cancer?) - indiscriminantly destroy the parent's own gametes, since they are likely full of errors due to unstable, error-prone tetrades formed in meiosis I. But this is all pure speculation and game developers themselves would probably wonder what the fuck we are talking about if they saw this debate.

Also, nothing in the game really indicates that radiation caused multiple FEV strains to be created (though it's very likely to happen, as FEV is an RNA virus and thus more prone to mutations). If anything, I'm pretty confident that supermutants were created using the original strain of FEV, since Mariposa vats likely weren't overly exposed to radiation. Large quantities of the virus that leaked out of the facility were much more likely to mutate into new strains, however, and I imagine that's why so many diverse mutations occured throughout the wasteland. Damaged and potentially defective strain of FEV, combined with host cells that were badly damaged by excessive amounts of radiation, are what probably led to inception of ghouls, radscorpions, brahmin, giant rats and other creatures. What I'm wondering about is to what extent all these creatures were affected by FEV, and how come they weren't rendered sterile? It seems reasonable to assume that all these species have become tetraploid, which gave them hardiness and resistance needed to survive in the wasteland. Brahmin's two-heads are another curious twist - my guess is that normal, domesticated cows already posses a recessive gene for two heads, and evolution to quad-helix structure allowed this gene to become dominant. It is definitely a useful trait, since it allows the cow to take in twice as much food and water, which is crucial for survival in the wasteland.

As for restoring mutant fertility, I doubt anything can be done in that respect. Insane Wanderer offered an interesting idea that might still allow them to reproduce, so I will expand on it with my above speculation. My theory assumes that supermutants are still capable of producing gametes at some point, so why not try and extract them before they are destroyed by the parent's metabolism, and then fertilize the egg artificially? The fertilized egg should be capable of self-repair. If not, we can always extract appropriate proteins (or whatever is responsible for DNA repair) from a parent's body and inject it into the fertilized cell. When the fetus grows, it can be implanted into the mother's uterus. Keep this up for a few thousand years, and maybe a random mutation might lead to birth of a species of fertile supermutants, which would undoubtedly quickly replace the "original" supermutants through the process of natural selection. Infrastructural and technological obstacles for such process in a post-apocalyptic word are another story, and frankly may be too grave to overcome.

Thorgrimm said:
Ah, it is good to see that NMA is still populated with vermin, who only come out of the dark to make fun of their betters. Another example of the 'superior intellect' you show Ratty, ratlike stupidity. As far as i can tell from your idiocy, you have not contributed anything but trolling stupidly on the Fallout boards. When you are able to rub two brain cells together and create something besides trollbait, then let me know. As i would enjoy greatly the sight of true intellect, not the parroting of it you show here. Get lost boy and don't bother your betters.
I honestly don't know what kind of an extra-terrestrial brazenness monster laid its larvae into your brain, but you have gone so far out of line with this post that it isn't even mildly amusing. If intellect is maniphested in ability to write unprovoked flames directed against people you don't even know, in response to posts that are clearly nothing more than a silly joke, then I prefer remaining the stupid rat that is unable to "rub two brain cells together", as you eloquently put it. Once you pull your head out of your ass, maybe you will come to understand that my purpose on these boards isn't to keep you pleased, and that crudely insulting a board regular without reason or provocation is frowned upon here. I took the liberty of skimming through some of your older posts, curious to see whether profound arrogance and lack of basic etiquette are present in all of them or if they are reserved only for me. Revelation dawned on me when in my search I came across a thread about your Civ 3 Fallout mod, where I criticized some of its aspects and offered some friendly suggestions. Though you reacted very civilly that time, now I truly see how well my criticism was received. I see maturity and ability to take constructive criticism aren't among your traits.

If you want any kind of reaction from me other than utter contempt in the future, your next post better be an apology. Until then, go find a mirror and masturbate to your own reflection, you rude, arrogant, unmannerly, egoistic, humorless piece of net trash.
 
Ratty, that was completely out of line. If it weren't for the rest of your post being very constructive and useful, that would be in the Vats now. Both of you stop it right now if you don't want to see your posts in the Vats.
 
Sander said:
Ratty, that was completely out of line. If it weren't for the rest of your post being very constructive and useful, that would be in the Vats now. Both of you stop it right now if you don't want to see your posts in the Vats.
My apologies for violating the rules, but I couldn't just let his insults slip. Don't worry, I'm now done with this nonsense for good.

Also, I appreciate you and Psycho jumping to my defense.
 
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