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HEADLINE: Jellyfish gene placed into monkey embryos;UW work on functioning foreign gene is a first

Milwaukee Journal Sentinel
September 11, 2001

University of Wisconsin-Madison researchers put a jellyfish
gene into a monkey embryo and got the foreign gene to work
in the placenta -- a scientific first and a step closer to making
a primate that's a true hybrid of two species. 

The goal isn't to make a monkey that swims, a fish that has
fur, or some other freakish, science-fictional creature. 

Instead, researchers want to make hybrids because by
swapping genes from one animal to another they can
determine which genes cause or cure a disease, or whether
altering or replacing a defective gene will help. For example,
the UW team has been studying the placenta -- the clump of
tissue that connects the fetus to the mother and nourishes it
throughout pregnancy. By swapping genes, they hope to
learn what causes miscarriages and a host of pregnancy

The team was led by UW scientist Thaddeus Golos and
included embryonic stem cell pioneer James Thomson and
scientists from the American Red Cross. The work was
published today in the Proceedings of the National Academy
of Sciences. 

Rhesus macaque monkeys are close genetic relatives to
humans and therefore ideal for helping test the safety and
effectiveness of human gene and stem cell therapy. In
genetic engineering experiments, scientists often use a
jellyfish gene because it produces a protein that glows
green, so it's easy to see which cells have incorporated it. 

In January, scientists at the Oregon Regional Primate
Research Center reported the birth of a monkey with a
jellyfish gene, but the gene was inactive -- not able to
function the way it does in the jellyfish. 

"They were able to get the DNA delivered to the offspring
but it doesn't do anything," explained Golos, who works at
the Wisconsin Regional Primate Research Center. 

The UW team achieved sort of the opposite. Using
six-day-old rhesus macaque embryos, they inserted the
jellyfish gene, implanted the genetically engineered embryos
into surrogate mother monkeys, and verified that the gene
was present and functioning in the placentas of two
monkeys later born live. 

The monkeys themselves didn't carry the jellyfish gene,
though the technique the UW researchers used could result
in monkeys that do, Golos said. 

It's the first time that a gene inserted into a primate embryo
has been shown to be functional throughout development to
a successful live birth, he said. And it's enough to enable
lots of research aimed at preventing a host of
pregnancy-related problems. 

"Our most important goal is to try to study placental
function," Golos said. "There are a lot of speculations but
very little hard fact on how the placenta functions." 

Doctors think that a problem with the placenta may be what
causes some women to have repeated miscarriages early in
their pregnancies. 

Placenta problems also have been suspected in some cases
of infertility, low birth-weight babies and pre-eclampsia, a
complication that affects as many as 10% or more of
first-time pregnancies and is a leading cause of
pregnancy-related illness and deaths, Golos said. 

The work on primates extends genetic engineering research
that has gone on for some time now involving fruit flies,
rabbits, sheep, goats, cattle, pigs and especially mice. 

The National Institutes of Health funded the work at UW
and in Oregon. 

LOAD-DATE: September 11, 2001