In yet another example of how Arizona Republicans have lost their minds, Governor Jan Brewer signed a bill last week that bans the creation of any “human-animal hybrid” for the purpose of research.
SB 1307 defines a “human-animal hybrid” as:
(a) A human embryo into which a nonhuman cell or cells, or any component part of a nonhuman cell or cells, have been introduced.
(b) A hybrid human-animal embryo produced by fertilizing a human egg with a nonhuman sperm.
(c) A hybrid human-animal embryo produced by fertilizing a nonhuman egg with human sperm.
(d) An embryo produced by introducing a nonhuman nucleus into a human egg.
(e) An embryo produced by introducing a human nucleus into a nonhuman egg.
(f) An embryo containing at least haploid sets of chromosomes from both a human and a nonhuman life form.
(g) A nonhuman life form engineered so that human gametes develop within the body of a nonhuman life form.
(h) A nonhuman life form engineered so that it contains a human brain or a brain derived wholly or predominantly from human neural tissues.
It’s not entirely clear that researchers in Arizona are attempting to produce any so-called “human-animal hybrids”. In fact, most researchers working on human stem cells work on, well, human stem cells; there are several human stem cell lines that are currently available to researchers.
However, the bill’s author, Representative Nancy Barto (R-Phoenix) claims that the bill was initiated by reports of a British group that developed human(-ish) stem cells by inserting human DNA into fertilized bovine eggs. Now, this technique is quite cool; basically, you take a fertilized egg and removet its nucleus (which contains all the DNA, the blueprints needed for functioning). You replace that nucleus with human DNA (obtained from skin cells), and allow the bovine proteins to operate under the instruction of the new DNA, producing cells that are 99.9% human stem cells.
However, because Republican politicians don’t understand science, they think that scientists are hell-bent on making the next ManBearPig, the half-man, half-bear, half-pig monstrousity popularized in South Park.
First of all, human stem cells generated by making “cybrids” (cellular hybrids of two species) will not produce a ManBearPig — if these cells are even viable in the long-term (which they’re not), they would produce a creature that is predominantly human. Secondly, there’s no value in making a ManBearPig; no one is interested in creating a human-animal hybrid creature.
Thirdly, and most importantly, existing laws prohibit the growth of human (or human-ish) embryos past 14 days, so there’s no fear that a human-ish Man-Cow would be made using this technique.
No, the reasoning behind SB 1307 is not fear that a Man-Cow will terrorize the streets of Phoenix; it’s a fear that human embryos should not be made by any method other than by fertilization of a human egg by a human sperm — preferentially in utero. What the British group has done is program a cow stem cell to act like a human stem cell, and it is the act of programming (and not the subsequent creation) that terrorizes Republicans like Representative Barto.
Consider, for example, that the bill forbids the creation of an embryo by any combination of human and non-human parts. Barto isn’t even concerned by the fact that fertilization of a human egg by a non-human sperm (or vice versa) is, generally, impossible (chromosome numbers make all the difference, here, as any high school biology textbook could tell you). No, Barto fears that she will be eaten by a Man-Cow.
SB 1307 also bans the creation of any population of human stem cells by any means other than fertilization of a human egg by a human sperm, and we cannot destroy the resuling population of cells for research. While the ban on “human-animal hybrids” is the hilarious part of SB 1307, the serious truth is that SB 1307 pretty much bans any human stem cell research in Arizona.
The problem here, though, is that bans like these actually limit the progress of science, and the cure of debilitating human diseases. In adult animals, most cells don’t grow — thus they have problems regenerating and repairing injuries caused by accident or disease. That’s why people with spinal cord injuries rarely regain function: their nerves are no longer able to grow to fix the damage. But, stem cells are cells whose only purpose is to grow. They can be readily encouraged to turn into nerve cells, skin cells, heart cells or liver cells — all just by putting them near the appropriate neighbour cells. Thus, these cells are theoretically capable of repairing any form of injury in the body.
But, because of existing hysteria regarding human stem cell research, scientists have limited access to human stem cells. Existing lines are contaminated with non-stem cells, and we cannot use existing embryonic tissue leftover from in vitro fertilization procedures (of which there are entire warehouses of unwanted material). So, the British scientists attempted to generate their own human stem cells using this “cybrid” technique — and it shows promise. If stem cells become a viable treatment alternative, “cybrids” may even be more cost-effective.
We can’t know how much promise stem cell research has for curing disease unless we, scientists, are allowed to figure it out. And legislation like SB 1307 — carried on capricious political winds — only throw roadblocks in front of science. How many people have to suffer, and ultimately die, due to cardiovascular disease, cancer, diabetes, and nerve-related injuries before these politicians will let scientists do our jobs in finding a cure?
