Three Parents Contribute to Experimental Human Embryo
gihan_ripper writes "It sounds like the storyline from a cheesy film, but a human embryo has been created using the genetic material from one man and two women. A team from Newcastle University, England, developed the technique in the hope that it could be used to prevent diseases caused by faulty mitochondria. Their experiment started with two ingredients: first, a left over (and 'severely abnormal') embryo from an IVF treatment; second, a donor egg from another woman. The donor egg has all but the mitochondrial DNA removed, then a nucleus from the embryo is inserted into the egg. Effectively, this results in a mitochondria transplant. 'While any baby born through this method would have genetic elements from three people, the nuclear DNA that influences appearance and other characteristics would not come from the woman providing the donor egg. However, the team only have permission to carry out the lab experiments and as yet this would not be allowed to be offered as a treatment.'"
To be clear, I'm not one of these "we must not play God, we're messing around with things we don't understand" types. At the same time, I do wonder if we understand the principles with which we're working as well as the write-up suggests. On the other hand, that is why we run experiments...
The write-up seems to carry some assumptions from our current model of how DNA and genetic inheritance works. "the nuclear DNA that influences appearance and other characteristics would not come from the woman providing the donor egg"... well, ok. Do genetic researchers understand why "cloned" animals don't always look like the parent? I've never heard it explained, and to my admittedly outsider point of view, that seems to raise some questions about how well we understand what determines "appearance and other characteristics" in complex organisms...
Mitochondrial DNA is always passed on by only the mother, this happens similarly in most metazoans. Mitochondrion present in sperm are marked with ubiquitin so that theyre destroyed once released into the zygote. As for genetic recombination being benificial...not really. Mitochondrial DNA only code for something like 35 genes. Some (like ribosomal RNA) would be completely dibilitating if defective, others not so much. Most of the proteins used in the mitochondria are actually coded in nuclear DNA, so they do benifit from recombination. Mitochondrial DNA actually will mutate fairly often due to the lack of recombination, and problems are common, but they usually arent serious...and often the problems stay sequestered to the area (within the body) where the mutation first occured.
Okay, so apparently as part of an experiment, just to see if it could be done, they fertilized human eggs, let the embryos develop for a few days, then killed them. Doesn't that bother ANYONE? Did I read that wrong? It sounds like they're creating people for experiments just to kill them! Yeah, I know a lot of you don't believe an embryo is a person, but I'm mainly posting for those who share my view but might have missed that aspect of the story.
Prov 9:8 Do not rebuke mockers or they will hate you; rebuke the wise and they will love you.
This short article leaves out the interesting issue of maternal RNA loading. Part of the reason the egg is so large is due to the actual production of the egg itself. Whereas sperm cells divide from a stem cell into 2 pre-sperm, then 4 sperm cells, a stem cell divides into 2 then 4 daughter cells. Only 1 of these cells becomes the egg, the other 3 are discarded. However, the other 3 pump their cytoplasm into the egg before being discarded, making the egg much larger. This transfer loads the egg with tons of maternal RNA that is free floating in the cytoplasm. This RNA will be used by the egg and newly formed fertilized cell before the cell can begin to make its own RNA. This maternal RNA does have an effect on the cell and its genetic expression. In this situation, the donor egg will have both mitochondria and its DNA in addition to RNA from the donor. While this RNA is only used for a short time, that time is a critical time in development and can control gene expression for the life of the organism.
OR...
Parents can prevent genetic diseases that run in their families
We cure several diseases related to mitochondria
Opens the door to other gene therapies
Fearing the unknown is unworthy of modern man. All knowledge is a double edged and people mock the ignorant because history seems to support the innovator.
Please turn to Bush and Pope as your guide to human affairs...I mean when has the Church or the President ever been wrong.