Implications of the three-parent embryo

(Oregon National Primate Research Center at OHSU)

Not all of our DNA that we inherit is in the nuclei of the egg and sperm that join at conception.  In the cytoplasm of our mother's egg are mitochondria.  Mitochondria have their own DNA called mtDNA.  We inherit our mtDNA only from our mother because sperm's mitochondria are dumped at conception.  There are genetic mutations that cause disease in mtDNA and a woman with a such a mutation cannot help but pass this mutation on to her children. 

This is where the three parent monkeys come in.  Here is how it works.  Scientists took the nucleus out of the mother's egg that had a mutation in her mtDNA and put it into the egg of another female monkey whose mtDNA was normal, after removing that nucleus of course.  They then fertilized the hybrid egg with monkey sperm and "Voila!" monkeys with genetic material from three parents.  From the UK Times Online:

In the research, published in the journal Nature, the modified eggs containing chromosomes from one female monkey and mitochondria from another, were fertilised by injecting a sperm. The resulting embryos were transferred to the wombs of surrogate mothers.

The first monkeys to be born were twins called Mito and Tracker, after a dye called MitoTracker used in the experiments. Two more monkeys were born after later experiments, named Spindler and Spindly after a genetic structure called the spindle along which chromosomes divide.

Tests showed that none of the monkeys had any trace of mitochondrial DNA from the mother that provided their nuclear DNA, suggesting that the process was successful. “We consider it a big achievement,” Dr Mitalipov said. “Anything we study and achieve in non-human primates can be translated much more easily to humans.”

The idea is now that this technology can be used in humans to prevent mothers with mitochondrial disease from passing the disease onto their children.  The Catholic Church would be opposed to this technique even though it was be characterized as genetic therapy because it requires the creation of human life in a dish.

Two important points to take home from this break-through in monkeys are, first, the push to use this technique in humans now.  One published study with a couple of monkeys and there are already calls to make this technology available to women with mitochondrial defects:

Professor Robin Lovell-Badge, of the National Institute for Medical Research in London, said: “These are proof-of-principle experiments suggesting that transfer of the nuclear genetic material from one egg to another may be a valid way to avoid the devastating problems associated with the inheritance of abnormal mitochondria that are present in the eggs of some women.

“It would seem unreasonable to delay real trials where any embryos produced were transferred to the women who wanted to avoid having children affected with these diseases.”

He added: “I think it is quite reasonable to activate the regulation-making power now.”

This is human experimentation straight up.  In the name of reproduction, some are willing to just throw caution to the wind and start implanting human embryos with 3 biological parents "now".  Because it would be "unreasonable" to delay human trials for all those poor women who are "desperate" to have biologically related children.  To hell with any possible long term effects.  (At least see if a few generations of these monkeys do not suffer from unforeseen complications first for pete's sake!)

The second important implication about this story is the ripple it is sending out in the UK.  To use this technique in humans in Britain, authorities would have to repeal the ban on implanting engineered embryos.  You know those embryos created by cloning with cow and rabbit eggs that they promised would never, ever see the darkness of a womb:

British scientists welcomed the Oregon study and urged the Government to change the law. The Human Fertilisation and Embryology Act (HFEA), passed last year, allows such experiments on embryos but made it illegal for altered embryos to be implanted into the womb. Ministers have the power to rescind this ban.

Ahhh, those pesky laws n' stuff.  Just toss it if it gets in the way.  That seems to be the trend these days.  Of course, at least Britian has such a law.  The United States is still contemplating its navel when it comes to regulating how human embryos are created and what is done to them.