For the first time, a human embryo has been created without a male DNA donor, scientists in Britain revealed today. The British press, though, is being careful not to call what was done 'cloning', for fear of public outcry, instead opting to use the eupemism of 'Parthenogenesis', Greek for
.
But don't worry, scientists at Edingburgh's Roslyn Institute, made famous for cloning Dolly the sheep, are telling us, this isn't really cloning. Far from it.
The difference between 'virgin conception' and 'cloning'? If I understand the technical issues correctly, parthogenesis stimulates a human egg to start dividing like an embryo without the addition of any genetic material. In other words, the cell is induced to begin dividing, splitting, and then growing on its own. Only the mother's DNA is present, but it is the DNA contained in the original cell. The cells are not implanted.
Cloning is when you inject the mother's DNA into an egg to start the process, and then implant the egg into a host womb.
1
this is a subject that im not very sure on how i feel about it...i mean, while i am Roman Catholic though not a very religious one, i do feel that HUMAN cloning is something that mankind should leave be...i dont know, maybe because i really know very little about cloning and really have very little interest in it, maybe thats why i feel the way i do about it..it just feels wrong, i remember when Dolly the sheep was cloned and i thought, oh cool, but wasnt that thrilled by it, and than when i heard how Dolly aged so much faster than normal i felt vindicated, that i was right to not feel that cloning was so wonderfull...guess ive seen way to many sci-fi movies involving human cloning to get too excited by it and feel that its a good thing to do...somethings should be left to nature i suppose,im always worried if some knucklehead scientist is going to open up Pandoras box and release something horrible on mankind and that will be all she wrote for us...just my thoughts on this
Posted by: THANOS35 at September 10, 2005 04:25 PM (QtMud)
2
Human clonning should be banned we dont need for them to create another bill clinton
Posted by: sandpiper at September 10, 2005 07:08 PM (JyNSh)
3
Yes, Dr. Shackleford, parthenogenisis is isomorphic with maternal cloning, as far as i can tell. The process begins at impact with a mechanical object, most likely a needle, which may or may not deliver a dna payload. Previous to about a year ago, mammalian eggs would not go full term, because of the mammalian dna imprinting problem, which has since been solved. My question for you is, exactly what is the difference between initiating liftoff of the fertilization membrane in the following scenarios, and which is/are cloning?
cell division initiated by needle prick
cell division initiated by needle delivery of another copy of maternal dna
cell division initiated by needle delivery of dna extracted
from unrelated XX
cell division initiated by needle delivery of XY dna
cell division initiated by sperm impact
Posted by: matoko kusanagi at September 10, 2005 09:15 PM (CMNwH)
4
Erm, yes, actually there is a difference.
First off, the term parthenogenisis is not a euphemisim, nor is it new. It is the scientific term for ths kind of process, and has been for over a hundred years (parthenogenisis occurs naturally in many species, and the process was named by naturalists studying such species. )
Secondly, it is not cloning. The BBC article does not say whether the cells produced are diploid (two sets of chromosomes, like normal cells), or haploid (one set of chromosomes, like egg cells, or sperm). Cloning (aka Cellular Nuclear Transfer, which is the actual term) always produces diploid cells. Parthenogenisis produces haploid cells, unless something is done to the egg to double it's chromosome number, first.
If these are haploid cells, then they could *NEVER* become an embryo. Period. they don't have the needed number of chromosomes.
Posted by: Monsyne Dragon at September 10, 2005 09:19 PM (Zhq+Y)
5
but Dragon, some aves and ranas can reproduce via parthenogenisis--are the offspring haploid?
Posted by: matoko kusanagi at September 10, 2005 10:00 PM (CMNwH)
6
still. same question--does the addition of a micropipette of genetic material make the difference between an embryo and a "parthenote"?
and neither the parthenote, maternal clone, or XX/XX embryo can be viable without dna imprinting--so are they embryos at all, and is it really cloning?
Posted by: matoko kusanagi at September 10, 2005 10:11 PM (CMNwH)
7
Goddammit! Bush was cloned from his own evil twin!!!
Posted by: Downing Street Memo at September 10, 2005 10:23 PM (TAhhF)
8
Hmm... From what I know, in the vertebrates that reproduce parthenogenically, various processes (depends on the species) double the chromosome number in the egg beforehand, so the offspring are diploid.
In insects, however, parthenogenisis often produces haploid individuals. (AFAIK, this is what determines the sex in some insects, one gender is diploid, the other haploid)
Posted by: Monsyne Dragon at September 11, 2005 12:42 AM (Zhq+Y)
9
So much for gays deriding straights as "breeders"...look to the the gay community to embrace this technology as a means to redefine "everything"...
Posted by: Grim at September 11, 2005 09:55 AM (6krEN)
10
Dragon, the def i was taught of cloning is that the offspring has the identical genetical makeup of the parent. I think the parthenotes in the article are not undergoing any sort of chromosome duplication, which is most likely why they are not working well. But if the brits are doubling the chromosomes, then parthenogenisis would be cloning, IMHO.
But that is not what i was really interested in, i am curious about the "personhood" of the classes i delineated before, parthenotes, invitro XX/XX with maternal dna, in vitro XX/XX with non-maternal dna, and invitro XX/XY. Let's add parthenotes with doubled chromosome compliment. Only the invitro XX/XY is viable without dna imprinting. Are the others actually embryos?
Posted by: matoko kusanagi at September 11, 2005 10:37 AM (CMNwH)
11
Human cloning is something that must be perfected now, before mankind initiates a nuclear holocaust which could very possibly have damaging effects on women's reproductive capabilities (not to mention the fact that women are becoming less fertile as time goes on anyway). For the sake of humanity, this is something that should be observed. We'd best be prepared. If we're not - Our entire human race may painfully fade out and disappear.
Stop stopping science from helping 'you.'
Posted by: madmagickdotnet at September 11, 2005 10:45 AM (7IS4Y)
12
Maybe I'm being simple-minded here, but....
Cloning animals is one thing, but just because we can do it, does it mean we should move on to humans? Curiosity and the want to advance scientific knowledge is a wonderful thing. But at what point does it become unethical? Who gets to decide who gets cloned when it becomes commonplace? Anyone here care to see another Hitler? Mussolini? OBL? It's one thing to clone a sheep; another to clone Stalin. With a little proper upbringing, they could be just like their predecessors in body AND spirit. Imagine the impact it would have on the psyche of others to see those faces again 20 years down the road.
Just like the nuclear bomb. It helped us win a war over evil, but now evil wants one too.
I vote NO. Some things are sacred and better left to nature.
Posted by: Oyster at September 12, 2005 06:31 AM (YudAC)
13
Silly Oyster, human cloning will be big business. But we won't actually grow full clones, we just want to grow brain-stemmed organ sacks for compatible transplants.
Posted by: matoko kusanagi at September 12, 2005 09:53 AM (CMNwH)
Hide Comments
| Add Comment
