Rachel Walker and Madeline Hall provided info on a project in New Zealand
to put human genes into cattle.  Geneticists call this making transgenic
animals.  I am a first year medical student just learning about transgenic
animals.  I am sure that there are many Lactnetters more proficient on this
subject than me, so feel free to add to this or correct me here.

Transgenic animals are being developed to produce human proteins that are
secreted in milk, but not (that I am aware of) to make milk for general
human consumption.  In effect, the animal becomes a factory to make a human
medication.   Ian Wilmut (the guy who cloned Dolly the sheep) had earlier
(in 1997) cloned Polly, a sheep who secretes Human Factor IX (a clotting
factor) in her milk. Presumably the idea is that the protein is then
extracted from the milk and delivered to hemophiliacs. I am not sure if
this is actually in clinical use yet, or still in the experimental phase.
The goal is to be able to produce large quantities of a protein in as
inexpensive a way as possible.  Mammary gland to the rescue!

The weird part in the press from New Zealand was

"Government scientists in Hamilton are planning to put human genes into
dairy cattle to breed cows that produce milk more akin to human breast
milk.


I wonder if the reporter just got the facts confused, or if this really is
the goal of the research? Putting human genes into an animal's milk does
NOT necessarily make it "more akin to human breast milk."


References:

Cloning for Medicine, Ian Wilmut, Scientific American, December 1998

Human Factor IX Transgenic Sheep Produced by Transfer of Nuclei from
Transfected Fetal Fibroblasts, E. Schnieke et al, Science, Vol 278, pages
2130-2133, December 1997


Kathleen Bellis
Penn State College of Medicine
Class of 2002