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Double trouble impedes cloning
Posted by: Prof. Dr. M. Raupp (IP Logged)
Date: February 26, 2007 02:52PM

www.checkbiotech.org ; www.raupp.info ; www.czu.cz

Like any good mother cow, she scampered around the pen, doing her best to
stay between her calf and curious visitors. The odd thing was that the
"mother" was a black-and-white Holstein, but her calf was a stocky,
reddish-brown Texas Longhorn, February 2007 by Harold Brubaker.

The scene was a converted farm in Lancaster County, where Cyagra Inc. has
one of the few commercial operations in the United States cloning barnyard
animals. Missy, the Texas Longhorn, was a copy - a clone - of a prized
member of a New Mexico herd who died young. She was implanted as 7-day-old
embryo in the Holstein, known as #97.

For now, Cyagra's cloning business is limited to such animals not raised for
food, but that could change this year.

The U.S. Food and Drug Administration issued a draft report Dec. 28 saying
that "meat and milk from clones of adult cattle, pigs and goats, and their
offspring, are as safe to eat as food from conventionally bred animals."

That FDA report - which also kept in place a voluntary moratorium on the use
of cloned animals for food - set the stage for a new round of debate about
agricultural technologies that are declared safe by regulators, but make
consumers nervous.

Even as genetically modified crops advance rapidly across America's fields,
skepticism and outright rejections from retailers and food companies could
keep cloning's business prospects in check.

Whole Foods Market Inc., the nation's largest natural and organic food
retailer, for example, said it did not intend to sell meat or milk from
cloned animals.

Even mainstream dairy companies are uncomfortable with cloning. "We're not
enthusiastic about any new technology that makes people think milk isn't as
pure and safe as we think it is," said Tom Wright, vice president of
marketing at ice-cream-maker Turkey Hill Dairy Inc.

Dean Foods Co., the largest U.S. milk processor, whose brands include Lehigh
Valley, said it would not accept milk directly from cloned cows, but the
Dallas company did not have a position on milk from the conventionally bred
progeny of clones.

"We're trying to define what is progeny," spokeswoman Marguerite Copel said.
At issue is how many generations beyond the clone are needed to dissipate
concerns about cloning.

Dealing with clones is complicated for industry because there is no way to
test for cloned products, and the FDA generally does not require labels on
foods it deems safe, such as those containing ingredients from genetically
modified crops. That means companies will have to do their own enforcement
if they are to avoid cloned animals.

Cloning is not new to the supermarket. Apples, for example, do not come from
seeds, but rather from clones made by grafting.

But even if food companies and consumers were to embrace animal cloning, its
cost would likely prevent mass-produced clones filling supermarket dairy and
meat cases, at least for the next decade.

Cyagra, for example, charges $17,000 for a healthy calf, said Steve A.
Mower, director of marketing for the subsidiary of an Argentinian
agricultural conglomerate.

That is prohibitively expensive for most dairy farmers, who pay as little as
$15 to artificially inseminate a cow.

Animal clones are "not going to be used for food production," said Terry D.
Etherton, a professor of dairy and animal science at Pennsylvania State
University in State College. "This will be a technology to clone genetically
superior animals that are used for breeding."

Cyagra has been selling clones since 2001 and now produces about 60 a year,
Mower said, the majority of them dairy and beef cattle prized as show
winners. He said 25 percent to 30 percent of its clones are Texas Longhorns
for wealthy hobbyists.

The process of cloning cattle at Cyagra, which is in West Donegal Township,
near Elizabethtown, begins with a pencil-eraser-size piece of skin from the
ear of the donor animal.

When the tissue arrives at Cyagra, Joshua Mann or another technician
processes the skin to extract fibroblast cells, which contain the animal's
complete DNA. Those cells grow in an incubator for two weeks. Those cells
can be used immediately for cloning or can be frozen and stored.

Cyagra charges $1,000 to grow a cell line. That includes the first year of
storage in liquid nitrogen. Thereafter, the storage fee is $90 a year.

To create the clone, Cyagra harvests immature eggs - called oocytes - from
ovaries shipped overnight from a slaughterhouse in Wisconsin.

Those are stained with a dye that attaches to the DNA in the oocyte, so it
glows a brilliant blue under black light. Using a tube that measures 1.2
millimeters on the outside and is sharpened to a nearly invisibly fine
point, Mann removes the DNA.

"He has a degree in Pac-Man," Mower said, referring to Mann. Mower's idea of
a video game might be outdated, but the point was on the mark, Mann said.
"It helps," Mann said of the hand-eye coordination that comes from video
games.

Mann then injects a cell from the animal being cloned into a precise
position in the egg and fuses it with an electrical or chemical shock. If
the fusion occurs, cell division will be visible under a microscope in 16 to
24 hours.

The embryos spend seven days in incubators, after which certain embryos are
selected for transfer into "recipients," such as #97, Missy's surrogate
mother. "In nine months, if everything goes right, we have a calf," Mower
said.

Cloning is so costly because the process is still dogged by a low efficiency
rate.

Of every 150 oocytes harvested from ovaries, only half are at the right
stage of development to be used for the DNA transfer.

Of those 75, only three-quarters, or about 56, are "fertilized," meaning
that the transferred DNA fuses into the recipient cell.

From there, 25 percent of the eggs, or 14, develop into embryos that can be
transferred into one of Cyagra's 130 recipients.

Finally, only about 15 percent, or 2, of the implanted embryos lead to a
birth - up from 2 percent in 2001, Mower said. That improvement has helped
bring the cost of a cloned calf down to $17,000 from $25,000 in 2001.

That is still too expensive for anything but top breeding cattle, said Tom
Lawlor, director of research at Holstein Association USA Inc., of
Brattleboro, Vt.

Semen from the top 30 or 40 Holstein bulls in the country sells for $50 to
$100 a "straw," which is a unit sold for artificial insemination. Such a
bull can earn $2 million to $3 million in annual revenue, Mower said.

For most dairy farmers, such as Samuel Matthews at Milky Way Farm in Chester
Springs, the high cost makes cloning irrelevant.

"If it's a cloned animal and people are trying to sell it, they are going to
be hyping it has the greatest cow that ever lived," said Matthews, who milks
30 cows and operates Chester Springs Creamery.

"The greatest cow that ever lived, I could never afford it anyway," he said.

[www.philly.com]



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