Wis. company announces cloning of calf
By Sid Perkins
UPI Science News
DEFOREST, Wis., Aug. 7 (UPI) -- A six-month-old Holstein named "Gene" was
trotted onto the stage today as the world's latest celebrity cloned animal
as officials announced plans to commercialize the cloning process.
The healthy young bull calf was produced by ABS Global, Inc., a Wisconsin
firm with a 56-year history in the cattle breeding business. The company
announced the cloning of the calf at a press conference today, and also
discussed their plans to spin off a subsidiary to commercialize the
cloning technology.
Michael D. Bishop, a vice president of research for Infigen, the new
subsidiary of ABS Global, says "Gene" was produced in a two-stage process.
First, scientists took the genetic material from a cell that came from a
30-day-old calf fetus and inserting it into an egg cell from which the
genetic material had been removed. This produced a single cell that was an
exact copy, or clone, of the cells in the 30-day-old fetus. Bishop says
cells that grew from this exact copy were then "reprogrammed."
In the second stage of the process, individual "reprogrammed" cells were
cloned again. This second-stage clone then developed into an immature
embryo for seven days and was then implanted into a recipient cow and
gestated for 280 days.
Bishop says the second cloning step seems to be important for proper
placental development in cows because, in earlier research, ABS scientists
were unable to get embryos from single-stage clones to remain implanted in
the recipient cow for longer than 55 days. He says each species of animal
will likely need a slightly different cloning process, due to such
differences in embryonic development.
The process used by ABS to clone "Gene" is somewhat different from the
process Scottish researchers used to produce "Dolly," the sheep. Bishop
says he believes "Dolly" was cloned in one step. Also, the genetic
material used to clone "Dolly" came from an udder cell of an adult,
six-year-old sheep. Cloning from adult cells is more difficult because the
cells have already specialized into specific cell types, such as skin,
muscle and bone.
Bishop says "Gene" was one of 18 embryos implanted into recipient cows --
three embryos had been implanted into six cows, but only "Gene" was
produced. He adds that further improvements have been made in the ABS
cloning process since "Gene" was cloned, and now ABS has more than 10
clone embryos in various stages of gestation.
Bishop says the ABS process can be used with any type of cell. He says,
"We can make an unlimited number of cells, freeze them for any amount of
time, then thaw them and make identical animals possessing a desired
trait."
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