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It is something that I imagine many transwomen would welcome, but even if such was possible, there is the problem with producing eggs.
I'm working on a story that sees MtF characters given fully functioning female reproductive organs, but with their genetic make up, there is a problem concerning their Y-chromosomes. Eggs always contain X-chromosomes, for reasons I shouldn't have to explain.
If there was a way for the created organs to overlook the Y-chromosome, and only ever use the single X-chromosome, then that would be one answer.
Another option would be for the persons Y-chromosomes to be changed into X-chromosomes, but that is something I can't see as being a realistic possibility.
The story involves the organs being created from stem cells, taken from the patient's mother. It is sci-fi to a degree, but creating organs from stem cells is something that is being investigated.
I just want your opinions and ideas on the matter.
Comments
Some issues
To be clear, I am not a licensed MD. A reproductive female pelvis is designed to permit the carrying and birth of a child. I think that if one was past the age of 25 it simply could not happen. Perhaps an implanted Uterus could carry the child but the birth would have to be by C section.
If a child transitioned before age 10, perhaps an endocrinologist could coax an XY body into thinking it was XX, but that is doubtful.
In writing the story, perhaps it would be best to abandon factual science and just go for it. You would have lots of company. I did it in two of my stories.
Gwen
Like my own story, sometimes
Like my own story, sometimes you just need enough science stuff to make it plausible.
Gwen: TBH I'd still totally go for the implanted uterus and have the c-section, for the chance to carry a child of my own.
For my bit, I'd suggest possible some sort of retroviral recoding of Y chromosome into a new X, possibly using DNA obtained from a female relative who isn't the mother (better than copying from own X and also removes maternal XX's to reduce chance of X-carried disorders).
If you're at a stage in a story where you can craft organs in such a way, a small bit of recoded chromosome isn't going to be too big a stretch.
.
Also not an MD (physics and engineering are my specialties with serious hobby level interest in things like biology, material science, medicine and forensics).
***
There is an average male skeleton and an average female skeleton and the two *are* different. However the skeletal difference between one random person (male or female) and another random person (male or female) is larger than the skeletal difference between an average known male and an average known female.
Bottom line is it can take an expert medical examiner a month or more to determine the sex of a skeleton, for the purpose of courtroom testimony, if said skeleton is the only evidence available. Occasionally the sex cannot be determined from skeleton-only-evidence, at least not well enough for the courtroom.
This does not negate what you said about the female pelvis. But it does highlight the fact that things are never as simple as they ought to be.
***
In the fairly near future (5 to 40 years, but this is just my personal guess) we will be confronted with technology that for all intents and purposes is magic. And I do mean to imply that something as radical as rebuilding the skeleton of a living person will become possible, even easy. Some early examples, precursors, of this tech are already commercially available, others are still in the labs with lots of money and other resources being applied.
It's going to be a wild ride.
T
It has happened in the real world...
Rachel Porter: "The story involves the organs being created from stem cells, taken from the patient's mother. It is sci-fi to a degree, but creating organs from stem cells is something that is being investigated."
...using stem cells created from any cell from the patient. A cheek swab is mentioned in some articles as sufficient to start the process. Since the process begins with cells from the patient, the ultimate organ is not subject to rejection.
An already known process changes the sample cells into adult stem cells. Additional known and newly developed processes are then used to start growing a thymus gland.
This partially formed pre-organ (?) is implanted where it will live, and it more or less finishes all by itself using the body's standard biochemical signaling system.
Wow.
Human trials can't be too far off.
FtM ought to be possible as well. Amputated limbs?
Google on "grow organs from stem cells thymus". A study using mice grew a fully functioning thymus glad to replace the original that had been removed. Reported in Aug of 2014.
T
more of an issue in my thinking
would be the fact of production of the proper hormonal bath for the fetus. eggs will attach and grow in other places than the uterus, so i dont think that will be a problem. there was a little discussion on this due to 3d printing of organs, and what would be entailed. if the whole system, not just the uterus was implanted, that makes it more likely to work of course.
Teresa L.
But unless something is done
But unless something is done to prohibit the Y-chromosome, then "male" eggs will be produced, leading to the possibility of a Y-Y embryo, which simply would not develop.
Actually I believe
that women are born with the egg in here ovaries if I recall High School Biology and Sex Ed correctly
.
That is my understanding as well. Thirteen eggs a year for 25 years would be 325 eggs for example, but each person is unique and her mileage will probably vary.
When the last one is gone, menopause happens.
T
BTW, did you know that human egg cells are large enough to be naked-eye-visible?
I Think
The near term solution to eggs is to harvest mature donor eggs, remove the nucleus or just the chromosomes and replace the nucleus or chromo's with those from the TS's own sperm. I think this is done now, replacing one egg's nucleus with that of another egg. I'm not sure, however, if this been done in humyns yet. In this case the mitochondrial DNA will be that of the egg donor, not the two sperm donors.
I think there is a present way of separating X bearing sperm cells from Y bearing ones; there might be a difference in density so the separation could be done with a centrifuge.
There are situations where a single X is used, ie, when a boy is conceived.
If a uterus were grown from the TS's own cells, which might be XY, I don't think it would matter. Milk glands work whether they grow from XX or XY cells; there just have to be the right hormones at the right levels present for milk to come.
Hugs and Bright Blessings,
Renee
Imprinting
Unfortunately, there would still be the hard genetic limit of genomic imprinting. Basically, for some genes, only the paternal or maternal copy is expressed - never both. You'd have to override that system too, but I guess oocytes development would do it for you. Otherwise, the most likely result would be a molar pregnancy, a condition in which a non-viable embryo is generated, that devolves into what is basically a womb tumor.
Also, don't forget eggs are produced by women during their foetal period, and stay dormant until puberty.
There ARE
There are documented cases of women with XY Chromosomes getting pregnant and carrying their children to term, birthing normally. There's at least one documented case where the XY daughter of an XY Mom, also got pregnant, carried her child to term and gave birth normally. So, having XY chromosomes will not preclude one from having babies (all other bits working).
As to Gwen's suggestion that it "might" be possible for the body of a M2F who transitions early to have a pelvis appropriate - As long as the child doesn't have a MALE puberty, then having only a female puberty should make most of the adjustments on the pelvis (not all, there IS a difference). But, that won't preclude carrying a bay safely. At worst, it would preclude "natural" childbirth. But, given the number of C-Sections that happen in our country, the M2F mom would be far from alone in needing one.
To take things a step further, there was a study done (10-20 years ago - I don't recall the exact time) where an embryo was implanted in the abdomen of a Gorilla (I think it was a Gorilla, but the exact species could be off.) where a good blood supply could be obtained. A placenta formed, etc. It was NOT allowed to come to term. They "aborted" the process after about a month, having proven that it was feasible.
There was a case of a woman with XY chromosomes in the UK, that turned out to have a "bit" of a uterus. With hormone treatment, the were able to trigger it's growth and she was able to have a baby.
There have also been efforts to "grow" various organs using the target's DNA, so they wouldn't be "rejected" and they've also 3-D printed "Ears" that were grafted on and functioned. (Outer Ear - cartilage and such.)
I guess what I'm saying is that if you are careful in how you describe the process in the story, it is conceivable that a M2F could be a mommy without pushing what is medically possible today very far, if at all.
Annette
I seem to remember something
I seem to remember something about the ligatures holding the stomach muscles in place being very different, something about the ability to give way, and allow for expansion during pregnancy.
Also, to my knowledge, spontaneous abortion of non viable fetuses are quite common. From what I've been told quite a few pregnancies are aborted only hours after conception due to genetic complications. These "pregnancies" usually goes undetected because they are so short lived. This could account for your Y-Y issue. In short the fertility rate would be halved.
Ummmm
An egg with a Y chromosome... Well if you were going for Sci-Fi horror, you could explore the possibility of a YY child. The ultimate male with something like roid rage, perhaps a "Hulk" kind of person... I don't know but that's what jumped into my twisted mind.
Hugs
Patricia
Happiness is being all dressed up and HAVING some place to go.
Semper in femineo gerunt
The story is definitely not
The story is definitely not horror. Its more good boy - good girl and bad boy - good boy/girl.
Doing research for my story...
Rachel, I'm researching this for my story. I saw an article about this and I think soon MtF will become bio-moms (and FtM become bio-dads) in the near future.
TGSine --958
I know I am late coming into
I know I am late coming into this discussion, but one of the ways couples can have gender specific children is to X or Y chromosome 'wash' the sperm.
Still rolling the dice on boy or girl baby...just the couple would not know if X or a Y chromosome EGG had been fertilized when all the X-only sperm came knocking.
Makes the role reversal all the complex