The tricked eggs divide for four or five days until they reach 50 to 100 cells – the blastocyst stage. These blastocysts should in theory yield stem cells, but because they are parthenogenetic – produced from the egg only – they cannot be viewed as a potential human life, says Karl Swann of the University of Wales College of Medicine in Cardiff, UK.
An enzyme which is normally present in sperm and involved in fertilization was isolated and applied to eggs with no sperm in sight.
Swann’s team tricked the eggs into dividing by injecting phospholipase C-zeta (PLC-zeta), an enzyme produced by sperm that Swann discovered two years ago with Cardiff colleague Tony Lai.
It sounds like Swann's group is repeating with human eggs a process he already demonstrated with mouse eggs a couple of years ago.
This brings up a question I raised in the context of possibly being able to some day isolate pluripotent stem cells from the blood of pregnant women: Will religiously motivated opponents of human embryonic stem cell research (hESC) find this latest technique to be an objectionable way to get cells to use to study embryo development or to induce cells to become organs? After all, there is no fertilization by a sperm (and, as we all know, Every Sperm is Sacred) to trigger the hypothesized moment of ensoulment. So are these cells ethically acceptable for stem cell research?
Biological scientists are going to continue to come up with new ways of manipulating cells that make them hard to place into traditional categories based on their origins. Either the religious folks are going to adopt a definition of human life as beginning at conception or they are going to have to define a cell as the beginning point of life by use of a still-to-be-elucidated statement of epigenetic state of an embryonic cell. If they go the latter route they are going to have to wait till science advances far enough that it can describe the epigenetic state (which will likely be a range of states) that can come into existence right after fertilization and then apply that definition to all other cells that have one of those states regardless of how it got there.
|Share |||Randall Parker, 2004 December 04 09:29 PM Biotech Organ Replacement|