HerpetologyFangirl Posted October 29, 2012 Share Posted October 29, 2012 Okay, so we all know that women have XX chromosomes, and men have XY sex genes. Occassionally something will go wrong, and people will be born who are XXY or XXX. These are facts. At the moment, I'm writing a fanfiction for Naruto, the anime. It's all purely fiction, and as such, certain liberties are being taken. There's a comparatively small subgenre of fanfiction called 'mpreg', where one of the male characters, usually a male in a gay relationship, somehow falls pregnant. In my story it's made possible through the consumption of a special medicine. It's more magic than science, but being a scientist myself, I can't help but think about some of the possible consequences of a male x male pregnancy. For example, in such a situation it would be possible for a YY baby to be conceived. There'd be a 25% chance of such an occurence with each conception. I would really like to hear your thoughts on how such a baby might develop, what sort of deformities it might have, whether or not such a foetus could even survive to term, or if it would more likely miscarry early on. Please humor my curiosity. It is, after all, the mark of a scientist. Link to comment Share on other sites More sharing options...
StringJunky Posted October 29, 2012 Share Posted October 29, 2012 Okay, so we all know that women have XX chromosomes, and men have XY sex genes. Occassionally something will go wrong, and people will be born who are XXY or XXX. These are facts. At the moment, I'm writing a fanfiction for Naruto, the anime. It's all purely fiction, and as such, certain liberties are being taken. There's a comparatively small subgenre of fanfiction called 'mpreg', where one of the male characters, usually a male in a gay relationship, somehow falls pregnant. In my story it's made possible through the consumption of a special medicine. It's more magic than science, but being a scientist myself, I can't help but think about some of the possible consequences of a male x male pregnancy. For example, in such a situation it would be possible for a YY baby to be conceived. There'd be a 25% chance of such an occurence with each conception. I would really like to hear your thoughts on how such a baby might develop, what sort of deformities it might have, whether or not such a foetus could even survive to term, or if it would more likely miscarry early on. Please humor my curiosity. It is, after all, the mark of a scientist. There is the not insignificant problem of it not having any mitochondria I suspect...I'm no biologist though. I understand this aspect of genetic coding comes from the female line only. Link to comment Share on other sites More sharing options...
HerpetologyFangirl Posted October 30, 2012 Author Share Posted October 30, 2012 In my story, taking the special medicine makes several changes to the male's body, in order to make him capable of conceiving and safely carrying a baby, such as converting a few hundred thousand sperm cells into egg cells (but not altering the DNA, which is why some eggs would have Y sex genes, thus making a YY baby possible) Also, things like making the pelvic bone more feminine, so he won't start walking funny when his baby bump grows in, etc. Given this information, would the foetus really have no mitochondria? Wouldn't that make it non-viable, and cause a miscarriage? Link to comment Share on other sites More sharing options...
ewmon Posted October 30, 2012 Share Posted October 30, 2012 A sperm has mitochondria but it would need some modification. I think the main point about a YY individual is the lack of an X chromosome, which does not determine gender but has other genes that are probably essential to the viability of the offspring. 2 Link to comment Share on other sites More sharing options...
Moontanman Posted October 30, 2012 Share Posted October 30, 2012 Since all foetuses start out female and later sexual dimorphism is determined by hormone levels and the effect they have on the genes of the foetus (yes it's quite possible for a XY baby to appear female in all respects) There are individuals with XXY XYY and XXX I doubt very seriously if a YY baby would develop at all. Mitochondria come from the female egg and have their own genes, they do not depend on the number or type of chromosomes contained in the developing foetus. http://www.marchofdimes.com/baby/birthdefects_chromosomal.html 1 Link to comment Share on other sites More sharing options...
HerpetologyFangirl Posted October 31, 2012 Author Share Posted October 31, 2012 Ewmon is thinking in the right direction. Like I mentioned before, when the guy drinks the medicine some of his sperm cells are changed into proper egg cells, only the DNA in the gamete stays the same, so the new egg cells would have all the mitochondria they needed. The real question is, could a foetus develop and be viable without an X chromosome? Link to comment Share on other sites More sharing options...
StringJunky Posted October 31, 2012 Share Posted October 31, 2012 ]Mitochondria come from the female egg and have their own genes I know I've said the above myself as well but I came across this: Mammalian mitochondrial DNA (mtDNA) is thought to be strictly maternally inherited.1,2 Sperm mitochondria disappear in early embryogenesis by selective destruction, inactivation, or simple dilution by the vast surplus of oocyte mitochondria.3 Very small amounts of paternally inherited mtDNA have been detected by the polymerase chain reaction (PCR) in mice after several generations of interspecific backcrosses.4 Studies of such hybrids and of mouse oocytes microinjected with sperm support the hypothesis that sperm mitochondria are targeted for destruction by nuclear-encoded proteins.5-7 We report the case of a 28-year-old man with mitochondrial myopathy due to a novel 2-bp mtDNA deletion in the ND2 gene (also known as MTND2), which encodes a subunit of the enzyme complex I of the mitochondrial respiratory chain. We determined that the mtDNA harboring the mutation was paternal in origin and accounted for 90 percent of the patient's muscle mtDNA. http://www.nejm.org/doi/full/10.1056/NEJMoa020350 Herpetologyfangirl, you could spin that aspect by saying the sperm was acquired from human strain that contained a persistent or transferable form of mtDNA or something like that. I'm sure Arete or CharonY could come up with something. Link to comment Share on other sites More sharing options...
jp255 Posted October 31, 2012 Share Posted October 31, 2012 YY in humans have never been observed, right? where as many other possible anueploidy and polyploidy of sex chromosomes has been observed. So probably not compatible with life. Also. Your special medicine will need to be able to induce a female genomic imprinting patern in one of the guy's germline cells. I don't know at what stage genomic imprinting is erased and reprogrammed as male in germline cells though. A male male imprinting pattern might not be compatible with life, I have no idea if it is compatible in humans or not. Even if it is, the baby would have many defects I think. So either the medicine or some other treatment will be neccessary to create the normal imprinting pattern. This imprinting pattern will probably be the most difficult issue to rectify in a real life foetus with two fathers using a surrogate mother, mitochondria could just be injected in I'd imagine. We don't know much if anything about the sex specific imprinting that occurs in germline cells at the moment. baby with two biological fathers should be possible in the future, legal in the future is a different issue heh. Link to comment Share on other sites More sharing options...
HerpetologyFangirl Posted October 31, 2012 Author Share Posted October 31, 2012 Wow, thanks for your contributions! ^.^ jp255, I don't think I'll be taking it quite that far in my story. If I get too technical, I'll start losing my audience. Sadly they aren't all scientists like us. Heck, even I'm a little fuzzy on my knowledge of imprinting patterns. I was just personally curious about what a YY baby would be like. Well, my story and the medicine is more magic than science, so I suppose I could make a YY baby viable if I really wanted to, but I much prefer to be accurate where I can. Besides, what kind of life would the overly-masculine boy have? Would he even be able to have kids of his own when he was old enough? Only sons, if it was possible at all. As a 'what if' thinker, I can't help but map out all of the possibilities in my mind, and look for the most interesting results of my musings. Thank you so much everyone, for indulging me like this! I really appreciate it. Link to comment Share on other sites More sharing options...
Moontanman Posted October 31, 2012 Share Posted October 31, 2012 You cannot have a YY baby, the Y chromosome is missing necessary genes for the development of the foetus. You can have a XYY baby but such individuals are developmentally retarded. http://www.newton.dep.anl.gov/askasci/mole00/mole00776.htm 1 Link to comment Share on other sites More sharing options...
HerpetologyFangirl Posted October 31, 2012 Author Share Posted October 31, 2012 (edited) "You cannot have a YY baby, the Y chromosome is missing necessary genes for the development of the foetus." Ah! This was the clear and concise reply which I was looking for from the beginning! Short, certain, and to-the-point. Thank you very much, Moontanman. :-D Edited October 31, 2012 by HerpetologyFangirl Link to comment Share on other sites More sharing options...
Jens Posted November 3, 2012 Share Posted November 3, 2012 In addition to what Moontanman has written... YY is 100% deadly. Some more details: X and Y chromosomes are nearly not related. The Y chromosome is not a short version of the X chromosome. In contrast to the X chromosomes the Y chromosome has nearly no genes. So YY means you miss the genes of one chromosome completly. This is always deadly. The human body is so fine tuned that it cannot even support having 2 active X chromosomes in one half of the population (the female half) and 1 active X chromosome in the other half (the male half). This is why one of the two X chromosomes in females is always completly deactivated (The one chosen is random). This means both men and women have only one active X chromosome and the men just have very few additional genes on the X chromosome. Link to comment Share on other sites More sharing options...
HerpetologyFangirl Posted November 4, 2012 Author Share Posted November 4, 2012 Thank you Jens, that was the precise information I was looking for. If that's the case, then I'm certain that a YY foetus would self-abort early on. That fits with my story. As sad as it is, a little angst goes a long way when you're writing fiction. Besides, the meaner I am to the characters which I love so much, the happier the endings I give them. ;-) If anyone is interested in reading my story, you can find it in Fanfiction.net. It's called 'Tea of Fate', by AnimeOtaku4444. Link to comment Share on other sites More sharing options...
POLLITO110 Posted February 7, 2013 Share Posted February 7, 2013 (edited) Since it's fiction, you can find your answer using maths. There is 47 XYY people than has a list of deformities. Then there are 45 X0 women with turner syndrome (a missing X). Then, a XYY baby with a missing X, Would be a YY. So a YY baby, could have the deformities of a XYY plus the deformities of the Turner syndrome, but note that some are the opposite in each syndrom like the average height. As the turner syndrome women need artificially remove blood from his uterus (if they receive hormonal threatment) every 3 months, because they do not have menstruation. Imagine a man that needs to have the blood removed from somewhere every 3 months for example. then the man has a webed neck... http://en.wikipedia.org/wiki/XYY_syndrome http://en.wikipedia.org/wiki/Turner_syndrome Edited February 7, 2013 by POLLITO110 Link to comment Share on other sites More sharing options...
Moontanman Posted February 7, 2013 Share Posted February 7, 2013 You cannot have a YY baby, the Y chromosome is missing necessary genes for the development of the foetus. You can have a XYY baby but such individuals are developmentally retarded. http://www.newton.dep.anl.gov/askasci/mole00/mole00776.htm the idea that XYY would result in a developmentally retarded individual is evidently not true, i apologize for that, my source was less than accurate in that regard... http://en.wikipedia.org/wiki/XYY_syndrome Link to comment Share on other sites More sharing options...
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