GENETICALLY MODIFIED ANIMALS
Claire Foster © 2006
Animal transgenics
Embryo stem cells from mice are
grown in laboratories in culture, and genes are targeted very precisely into
the embryo stem cells, which then start to grow in the laboratory. These
modified cells are then injected into an embryo, placed in a surrogate mouse
mother, and after one generation of breeding, a transgenic mouse is
produced. This technique thus produces 100% transgenic animals with
precisely engineered modifications. Such transgenic mice are widely used
in medical research (e.g. the oncomouse).
Is it ethical to create animals like
this? Does the fact that these animals help to discover better treatments
for human diseases justify their creation and use in research?
Goal-based question: What is
the intended outcome of creating transgenetic
animals? Is it important?
Duty-based question: Will the
animals suffer in any way from being used for research?
Right-based question: The
animals’ consent cannot be sought and there is no autonomy to be
respected. If the animal has a right not to be harmed, this is covered by
the duty-based question.
Scientists have been unable to
produce embryo stem cells in farm animals and so have not been able to produce
transgenic farm animals with desirable traits such as protein-enhanced milk or
low fat meat. Scientists at the Roslin
Institute famously overcame this problem by using sheep cells that were at
later stages of development than the embryo stem cells of the mice. In a
laboratory, the scientists were able to control the conditions of growth of
these more mature cells and reprogramme their nuclei
so they would function within a growing embryo. These reprogrammed nuclei
could then be transferred into an unfertilised egg and placed in the womb of a
surrogate mother who would then give birth to a live lamb – Dolly. It
took 247 attempts to achieve a live birth. It was the fact that this
process of nuclear transfer could be done with adult cells that gave rise to
the possibility of successful cloning.
Is it ethical to clone
animals? Would it be ethical to clone humans?
Goal-based question: Is
cloning animals serving the common good?
Duty-based question: What harm
might be suffered by the animals? Note
that it took 247 failed attempts to produced Dolly.