View Full Version : Human parthenogenesis?


Buckaroo Banzai
05-15-04, 03:23 PM
I've read in some places, briefly statements that is possible to a woman get pregnant of hersef, by her egg being fertilized by one of her polar corpuscles. This is true? Is it only possible, or have already happened? (can't be Jesus, from this sort of thing wouldn't result any male :p )

eddymrsci
05-15-04, 03:40 PM
wow, that sounds pretty interesting. I once did some research on parthenogenesis for a science project, and I thought the process occurs consistently only in relatively simpler organisms such as aphids and possibly even ants.
(have you seen Jurassic Park, those female dinosaurs underwent parthenogenesis in order to reproduce :p haha but that's only fiction)
Well, "Life will find a way..." (From Jurassic Park):)

Buckaroo Banzai
05-16-04, 11:50 AM
There's also at least a species of rock lizards, Lacerta unisexualis... I've found a paper about that somewhere in the internet once.

eddymrsci
05-16-04, 11:56 AM
oh that's neat, let me be honest with you, for that science project, I was trying to test if parthenogenesis occurs in fruit flies (Drosophila Melanogaster) under certain conditions, and the results were negative. :(

Enigma'07
05-16-04, 12:53 PM
I've heard about those lizards before in a biology class. They said that the offspring is essantionialy a clone of it's mother.

ElectricFetus
05-16-04, 03:03 PM
Ya hypothetically its possible, but I have never heard of a proven case of it happening in humans let alone mammals (well except for that one time were they made a mouse give birth to its own clone). By the way a women could only have a girl by parthenogenesis, it would not be a clone genetically because the genes have all be rearranged but it would likely look like a clone.
There are many biologist trying to develop theories that explain how it s impossible, kind of like how physicist making theories on how time travel should be impossible.

Buckaroo Banzai
05-17-04, 05:20 PM
Altough that I certainly agree that it is very improbable, I'd not say confidently that's impossible... not after hearing about a thing that suposed happened with a woman in Italy, is said that she gave birth to his baby, and then they verified that she was still pregnant of twins... I do not know how it managed to occur... if really occurred. :bugeye:

weebee
05-18-04, 01:59 PM
anyone know if anyone has looked at the imprinting pattern of the polar body?

I've heard of a cancer which makes the unfertilized egg grow and divide. Still...
http://story.news.yahoo.com/news?tmpl=story&cid=571&e=20&u=/nm/health_sperm_dc
Dads Deliver More Than Just DNA, Scientists Say

Enigma'07
05-24-04, 02:56 PM
Parthenogenesis can occur in human females. If a certain series of hormones is triggered, evan in the abstance of sperm an egg can still start developing. It is only hapliod, but it develops into a tumor that has hair and teeth. Freaky!

Buckaroo Banzai
05-25-04, 07:50 PM
Before I read the conclusion I've thought for a second that the egg developed in a X0 person....

2inquisitive
05-26-04, 03:23 AM
I just came across this thread. Parthenogenesis is not all that uncommon reptiles, for
instance, there have been several snakes in zoos which produced young without a
male being anywhere around, ala Jurassic Park. I thought I remembered reading
something fairly recently about a large mammal (can't remember what) that gave birth
through parthenogenesis in a zoo, but I can't find a link, so I may be mistaken. I do
have a link to the birth of bamboo sharks by parthenogenisis in a zoo. It was supposed
to have happened with some other sharks in another zoo, also.
http://news.nationalgeographic.com/news/2002/09/0925_020925_virginshark.html

Buckaroo Banzai
11-25-04, 02:01 PM
Resurrecting one of my creations.....

I think that what I first suggested as parthenogenesis wasn't really this, since it involves fertilization of an egg by a corpuscle, and not an unfertilized egg developing spontaneously. I don't know how it would be called though... anyway, recently I found this dubious site with somethings on "virgin birth":
http://ourworld.compuserve.com/homepages/dp5/sex2.htm

In this page is said that the parovarium (organ of RosenmŁller) can produce sperm-like cells (they say "sperm"! not sperm-like...) that can fertilize her eggs. Anyone knows if that's true?


About true parthenogenesis in humans this site says

There is some evidence, however, that natural parthenogenesis does occasionally occur in humans. There are many instances in which impregnation has allegedly taken place in women without there being any possibility of the semen entering the female genital passage [2]. In some cases it was found either in the course of pregnancy or at the time of childbirth that the female passages were obstructed. In 1956 the medical journal Lancet published a report concerning 19 alleged cases of virgin birth among women in England, who were studied by members of the British Medical Association. The six-month study convinced the investigators that human parthenogenesis was physiologically possible and had actually occurred in some of the women studied [3].

refs.

2. Raymond Bernard, The Mysteries of Human Reproduction, Mokelumne Hill, CA: Health Research, n.d., pp. 47-50, 56-63.
3. Ibid., pp. 3-10.

I don't know what "ibid" means, I guess that means that refers to the previous source of reference, but different pages....

Researching through google I found that parthenogenesis really occurs in humans, but in anywhere but in this site I found that a parthenote embryo can develop completely as a fertylized embryo, rather parthenotes result in teratomas, what was cited few posts ago by Enigma'07. I've found that teratomas can have several specialized tissues and organs, such as glands and even eyes, but in a messed manner. Although there's a phenomena called fetus in fetu, which some people think that may be a highly organized teratoma, I think I've read something about a functional heart.

This thing led me to think in a analogy for development, and I would like to know if this is valid, from someone expertised in this issues. Development would be like pulling, causing to fall a domino, triggering the fall of lots of dominoes organized in lines. Normal embryonic development, on fertilized eggs, would be like pulling the correct first domino piece; teratomas would be like pulling a domino on the middle of the way, causing to only a few of the pieces fall correcly, as planned.
If this analogy is valid, seems that a tremendous luck could result in a fully-correct developed parthenote (excluding non-letal effects of monosmomy... if such thing really could happen)... or there's something more fundamental in the development of mammals that crucially needs fertlization (by a male, necessarily, or female self-fertilization would fit?)?

hypatia
11-26-04, 02:15 AM
I think someone above mentioned this: the imprinting pattern has to be correct for viable offspring to result.

That is, patterns of DNA methylation are different in male and female gametes. If a polar body were to fertilize an ovum (which sounds next to impossible, since it doesn't have the swimming and targeting machinery the sperm uses to find and fuse with the egg), the resulting embryo would have a double pattern of 'mom gene' methylation and no 'dad gene' methylation. I doubt it would be viable.

Kumar
11-26-04, 05:35 AM
Can there be any possibilty of somewhat "self cloning"--a women get her own DNA to egg(if blank egg can be possible in natural way)? We sometimes see offspring matching exactly to either mother or father. If it can happen then women can only get a female baby.??

Buckaroo Banzai
03-30-05, 09:12 AM
Update from the fan of the odd and the weird.
Look what I've found:


In 1995, for instance, Bonthron described another boy who was partially parthenogenetic: cells from his blood and certain other tissues contained none of his father's chromosomes; instead, they featured a duplicated set of one half of his mother's6. Although it is not unknown for an egg to start developing without being fertilized, fully parthenogenetic human embryos cannot develop to term. Bonthron, now at the University of Leeds, UK, believes that the partially parthenogenetic boy owed his unusual genetic constitution to an egg that spontaneously divided into two cells, one of which was fertilized. The second cell then copied its maternal chromosomes, allowing the resulting chimaera to form a viable embryo.
http://www.unc.edu/courses/2002fall/biol/122/001/Human%20genetics%20Dual%20identities_files/DynaPage(1).htm


Kumar,
I'm not sure about the self cloning part, I guess that as in the gametogenesis allways gets only half of the genotype, so an hipothetical parthenote could never be a clone of the mother.
But in any instance that parthenogenesis occur, it only results in females, or at least in species in which females are determined by a pair of X chromossomes, or something like it.

S.A.M.
07-05-07, 06:55 PM
George was dumbfounded.

He had been examining the shark, Tidbit, to figure out why she reacted badly to routine sedatives during a physical and died, hours after biting an aquarium curator on the shin. Now there was a bigger mystery: How did Tidbit get pregnant?

"We must have had hanky panky" in the shark tank, he thought.

But sharks only breed with sharks of the same species, and there were no male blacktip reef sharks at the Virginia Aquarium & Marine Science Center in Virginia Beach.

Could Tidbit have defied nature, resulting in the first known shark hybrid?

A recent study had documented the first confirmed case of asexual reproduction, or parthenogenesis, among sharks: a pup born at a Nebraska zoo came from an egg that developed in a female shark without sperm from a male.

One of the scientists who worked on that study contacted the aquarium, which sent him tissue samples from Tidbit and her pup for testing. If the pup's DNA turns out to contain no contribution from a male shark, this would be the second known case of shark parthenogenesis.

http://www.boston.com/news/science/articles/2007/06/25/shark_bite_leads_to_reproduction_mystery/

Asexual reproduction in sharks?:confused:

iceaura
07-05-07, 07:13 PM
I think mammals are just about the only major group of living beings that do not do this, ever.

Might have something to do with the internal womb and placenta.

Buckaroo Banzai
03-26-08, 02:37 PM
Back to this eerie subject again. Adding some stuff I think wasn't mentioned before:


Mature ovarian cystic teratoma with a highly differentiated homunculus: A case report

[...]In this report, we document a case in which the solid portion of an ovarian teratoma demonstrated considerable differentiation, forming a doll-like structure.

A 25-year-old virginal Japanese woman underwent surgery for an ovarian tumor that was diagnosed as a mature teratoma. A solid mass within the tumor was found to have a head, trunk, and extremities. Consequently, this mass was diagnosed as a mature fetiform teratoma (homunculus). Brain, eye, spinal nerve, ear, teeth, thyroid gland, bone, bone marrow, gut, trachea, blood vessels, and phallic cavernous tissue were confirmed microscopically. Distinctive features were the clear anterior-posterior, ventral-dorsal, and left-right axes, with a spatially well-organized arrangement of the organs. An eye was located on the front of the head, a spinal nerve lay dorsal to the spinal bones, the thyroid gland was anterior to the trachea, and the gut was deep inside the trunk.

[...]

http://doi.wiley.com/10.1002/bdra.10133






[...] It has been proposed that fetiform teratoma and fetus in fetu can be differentiated based on zygosity.4,9,16 As previously mentioned, most ovarian teratomas are homozygous at loci where the host normal tissue demonstrates heterozygosity, but fetus in fetu is genetically identical to its host. Cytogenetic examination was not performed on this case.

Clinically, ovarian fetiform teratomas and fetus in fetu present differently. Most reported cases of the latter have been discovered in infancy as an abdominal mass, and no case has been reported within an ovary.14,15 The most common location is retroperitoneal, although cases have been reported in the skull, sacrum, mouth, and scrotum as well.14,15 In contrast, fetiform teratomas are most commonly found in women of reproductive age and discovered as ovarian masses.3

Fetiform teratomas must also be distinguished from ectopic pregnancies. All reported cases of fetiform teratoma are composed of mature tissue and present without placental or trophoblastic tissue.4 However, there have been 2 reported cases of umbilical cord structures described in fetiform teratomas, in which histologic evaluation was not performed.4 A clinical history of an elevated β-human chorionic gonadotropin level and the documentation of chorionic tissue can substantiate the diagnosis of an ectopic pregnancy. [...]

http://arpa.allenpress.com/arpaonline/?request=get-document&doi=10.1043%2F1543-2165(2006)130%5B1552:FTH%5D2.0.CO%3B2




The last one states that homunculi have never been found with skeletal muscle, but another article reports such a case:


The limb buds and rudimentary digits consisted of rudimentary cartilage surrounded by fat, neurovascular bundles, and minute amounts of skeletal muscle with overlying skin (Figure 4, a).

http://findarticles.com/p/articles/mi_qa3725/is_200610/ai_n17196260/pg_2







I'm almost sure I've read once about instances where a normal non-parthenogenic zygote develops into a "normal" teratoma-like mess of unorganized tissues and organs. Anyone knows how it's called?

draqon
03-26-08, 02:42 PM
I've read in some places, briefly statements that is possible to a woman get pregnant of hersef, by her egg being fertilized by one of her polar corpuscles. This is true? Is it only possible, or have already happened? (can't be Jesus, from this sort of thing wouldn't result any male :p )

this introduces fallacies in DNA replication...and the likelyhood that an offspring will be a mutant or have problems is quite high.

Buckaroo Banzai
03-27-08, 12:15 AM
What is a "fallacy" in DNA replication?

The zygote wouldn't be exactly a mutant, but would have increased risk of problems related with homozigosity, and as with true parthenotes, probably problems of low-viability due to lack of a complementary male pattern of DNA methylation.


By the way, about the methylation subject, I've read in another forum someone suggesting that maybe a XXY woman could have this "solved". But I don't remember anything about this syndrome, I thougth that usually an abnormal number of sex chromosomes would result in sterility.

And I also think that maybe, somehow, the gametogenesis may just keep with the individual woman's "normal" methylation pattern, as if it was just a regular somatic cell in this regard.

Veritas
02-05-10, 01:03 PM
Just a little confused here. If the parthenogenetic child is derived solely from the mother's DNA, and the mother's DNA is a composite of her biological mother and father, would not the odds of producing a male be equal to the odds of producing a female?

Enmos
02-05-10, 01:17 PM
Just a little confused here. If the parthenogenetic child is derived solely from the mother's DNA, and the mother's DNA is a composite of her biological mother and father, would not the odds of producing a male be equal to the odds of producing a female?


People have so-called sex-chromosomes. Males have an X-chromosome and an Y-chromosome, while women have two X-chromosomes.
Each sperm cell gets just one of those, so either an X-chromosome or an Y-chromosome.
Each egg cell gets one of the X-chromosomes.
When the egg gets fertilized by a sperm cell containing a Y-chromosome, the result will be a male (XY).
When it gets fertilized by a sperm cell containing an X-chromosome, the result will be a female (XX).

I hope this helps.
Here's a short article about the subject: http://biology.about.com/od/basicgenetics/p/chromosgender.htm

Edit: So to answer you question: no. Females only have X-chromosomes so there is no chance of ever producing a male by parthenogenesis.

Welcome to SciForums, by the way :)

Hercules Rockefeller
02-10-10, 05:10 PM
I havenít read all the posts in detail, so sorry if Iím repeating whatís already been said.

There is sometimes confusion when it comes to parthenogenesis in mammals. Parthenogenesis in mammals, including humans, can occur by natural or artificial means. However, mammalian parthenogenetic ova/embryos are not viable and do not develop beyond an early embryonic stage. This is because of a strict reliance on imprinting in mammalian embryos. ie. embryonic development requires the input of both maternal and paternal genes.

rimibchatterjee
09-28-10, 12:46 AM
I'm a writer based in India currently doing research for my fourth novel, which is set five hundred years in the future. I have a question regarding human parthenogenesis. I'd like to know if it is technically possible to turn off imprinting, merge the haploid genomes of two eggs and produce a viable embryo for implantation in a womb that could be carried to term and produce a healthy (female) human being. In other words, is it possible to develop a technology that facilitates diploid parthenogenesis using a donated egg in lieu of sperm, provided DNA methylation and imprinting can be turned off, or adapted? What I'm trying to get at is, is there any gamestopper feature of the normal fertilization process that rules out such a possibility?
Hope I'm clear :)

WillNever
09-28-10, 02:09 PM
I didn't read the responses in this thread since they seemed at glance to be rather uninformative... but are you talking about a molar pregnancy..? If so, that isn't a baby. It's just a tumor. You're not going to deliver a child out of that.

Hercules Rockefeller
09-29-10, 12:23 PM
I'm a writer based in India currently doing research for my fourth novel, which is set five hundred years in the future. I have a question regarding human parthenogenesis. I'd like to know if it is technically possible to turn off imprinting, merge the haploid genomes of two eggs and produce a viable embryo for implantation in a womb that could be carried to term and produce a healthy (female) human being.


A publication in 2001 described the fertilisation of mouse oocytes with female somatic cells. It required a great deal of artificial laboratory assistance and manipulation but they did manage to create blastocysts from such ďfemale-female matingĒ experiments. This is pretty much along the lines of what you are imagining.

Fertilization of mouse oocytes using somatic cells as male germ cells
http://www.rbmojournal.com/article/S1472-6483(10)62037-8/abstract (http://www.rbmojournal.com/article/S1472-6483(10)62037-8/abstract)

However, they didnít implant the blastocysts so it was unknown whether these early embryos were capable of developing into a full-term pregnancy. Even if the blastocysts could have implanted thereís still the problem of overcoming the need for male imprinting for embryonic development. I donít know if there have been any further advances since then; I used to be in the developmental biology field back then but have since moved into another field and Iím out of the loop with respect to these sorts of issues.

But, given another 500 years I would say the answer to your question is yes! I can see a high probability of us having the technology to create new babies via an artificial female-female sexual reproduction without the need for any male genetic input.

rimibchatterjee
09-29-10, 01:12 PM
Thanks HR, that is extremely helpful. I guess I shall have to invent a technology to deal with imprinting, which as far as I've been able to determine is thought to occur by selective methylation of certain DNA strands, thus knocking em out of action. I don't need to bore my readers with the details, but I do need to get it straight in my head so I don't say something conspicuously foolish and get jumped on by scientists :)

aaqucnaona
08-24-12, 06:35 AM
Issac Roman was disappointed. A messenger for the Roman emperor, he had arrived that morning after an ardeous journey bearing a news that he believed might get him a mention in the royal records. He met with the scribe who called on the royal historian, who had just finished a catalogue illustrating the digestive irregularities of the emperor. He brought news he claimed was confired by the local healer woman - a female called Mary had bore a child dispite being [she claimed] a virgin. The scribe and the historian both found this news rather unremarkable and decided not to mention it in the records. And so it happened with hundrens of messengers to many local chiefs too. And 30 years later when that child, now all grown up, was reported to have become an accomplished illusionist and was reported to be forming a quickly growing 'new religion' cult. Yet again, this failed to impress historians, biographers and record keepers anywhere. Little did they know this was to become, well, you know where I am going with this and I have already taken a fairly large detour from my intended subject matter. So mods, pls break off this section into the comparitive religion section if it distracts too much from the discussion at hand.

Now then, unlikely as it is, if something like this actually happened, the only possible way for it to occur would be parthenogenesis. Of course, Jesus would not be a male for there is no male dna to code for the design of a beard or penis or balls,etc but then the child of God cant be a female, can it - might give the women the will to leave the kitchen! Ohhhhhh... alternative history sexism, LOLZ. But if there is ever a virgin birth, how would it occur in a human? Lizards do it, one species, to my knowledge, is even entirely female. CAN partenogenesis occur in Humans? Is it reported in any mammals at all? What about in primates? IS any research being done in this matter? Seing how much money is put in creation museams, you would think someone might actually research this, no?