It’s obvious from yesterday’s vote that embryonic stem cells will continue to split the country (California versus Washington DC, for one thing). But in an ironic bit of timing researchers at the Reproductive Genetics Institute have just published some results at Reproductive BioMedicine Online that could–possibly–short-circuit some of the arguments against using embryonic stem cells.

The RGI researchers have figured out how to derive stem cells from a four-day old embryo–a stage known as a morula. Until now, scientists have been using older blastocysts, and have been destroying them in the process. But when the RGI team took a single cell from a morula, it still had the capacity to develop into a normal embryo. That means that parents who are doing IVF could conceivably agree to have a cell removed from their morula, which could then give rise to a line of stem cells, while the morula developed into an embryo ready for implanting. The stem cell line could be banked for therapy, or used for research.

I first read about this in an article published yesterday on the article requires a subscription). Neither the article nor the abstract I linked to makes it clear whether this could be a viable source of stem cells for the large-scale research that scientists really want to do. But the results are enough to inspire a thought experiment.

Let’s say you object to stem cell research because each blastocyst is a unique human being with a unique genome and the capacity for life. Destroying one is therefore murder. Would this “morula method” be acceptable to you? It seems like it has the benefits of adult stem cell research (no controversy over destroying embryos) and the benefits of embryonic stem cell research (the possibility of discovering therapies that can’t be derived from adult stem cells). Or does any tinkering with embryos set off alarms? Perhaps we’ll find out in a Senate hearing.

Originally published November 3, 2004. Copyright 2004 Carl Zimmer.