Janus’ report is not about cloning, it’s about parthenogenesis, or the stimulation of the female gamete to begin duplicating its chromosomes and then to divide and make daughter cells. In other words, the oocyte becomes an embryo without fertilization by another gamete, a sperm.
The technique requires an oocyte to be available in the lab - not an easy feat, as the researchers in Great Britain and California could tell you. The lack of willing donors has spurred controversy over paying for donation and even a drive to use non-human oocytes in cloning research.
In this case, though, Dr. Daley has it right, and yet once again, Ronald Green is wrong: the entity that the embryonic stem cells come from is an embryo, developed in a way that’s not seen in humans in nature. However, if it looks like an embryo and makes cells that act like embryonic cells, it’s an embryo.
In humans, the centromeres that allow the chromosomes to line up properly and regulate the division of the cell are found in the sperm, so the parthenogenetic embryo only lives a short time. But that does not make her anything less than a disabled human embryo, and one that is deliberately created in that disabled state for the use she’ll have to researchers.
That’s just bad ethics.
The only way to find out whether the result of parthenogenesis is an embryo is to grow and develop as far as possible.
We read last month about new evidence that sharks are able to reproduce by parthenogenesis.http://news.bbc.co.uk/2/hi/science/nature/6681793.stm By turning off a given gene in mice, scientists have been able to produce mice using two separate lines of oocytes, from two females. One of these mice grew up to have pups the normal way. http://www.newscientist.com/article.ns?id=dn4909
The only benefit to this research is publicity value and the doubt that is created by noting how un-natural the process is.
This is not the time to create new ethics - old ethics works. If you’re not sure whether or not there’s an embryo, don’t do it, if you are sure, certainly don’t do it.
Melinator, if you had a twin, what would keep you from harvesting him or her for your stem cells? A clone is simply your twin. The very thing that would make your clone useful to you - if the bugs are ever worked out of the research - is the fact that he or she is a genetic copy of you, at a young age.
Interesting story of the shark “virgin birth.” It appears it was the result of the merger of two egg cells, similar to the mouse example. I.e. a kind of pseudo sperm. Having it happen with only one intact egg cell would be a closer parallel to this.
I think it was Abraham Lincoln who once said that if you call a sheep's tail a leg, it still is a tail! Same thing here. When you remove the genetic material from an oocyte and replace it with the genetic material from a somatic cell, that IS CLONING. People have given it all kinds of names, in order to make it sound "good", but it is still cloning.
the oocyte becomes an embryo without fertilization by another gamete, a sperm
Exactly! That's what cloning is all about! Reproduction without fertilization.
the centromeres that allow the chromosomes to line up properly and regulate the division of the cell are found in the sperm
Really? Where did you learn that? And I have been teaching my students that a centromere is part of any chromosome! Seriously, if you could back up that statement you would probably qualify for the next Nobel prize in Medicine. But if you can't, you'd better stop trying to mislead people by using "big words".
I'm not familiar with the mouse experiments that you refer to. If you can give me a reference more reliable than Newscientist I'll be glad to have a look at it.
The level of development of my clone would govern whether or not I had any qualms about harvesting him. If he is embryonic and I can make multiple copies of him, I harvest away as needed. If he is my twin by natural childbirth, I couldn’t possibly do the same thing, for all the obvious reasons.