ANIMAL TRANSPLANTS FOR SPECIES SURVIVAL
(Editor's note: In the beginning computers could only communicate in
capital letters. This is one of 20 columns from Dr. Tomorrow's original
series, included here to indicate change as well as describe it. Those
columns also hold another story, that change is swift and offers both
disaster and opportunity.)
MAN'S RECENT RAPID SPURT IN POPULATION GROWTH HAS MADE LIFE ON THIS
PLANET A BIT DIFFICULT FOR SOME OTHER RESIDENTS. MANY SPECIES OF
ANIMALS, BIRDS AND REPTILES HAVE SEEN THEIR NUMBERS SHRINK AS THEIR
HABITATS HAVE BEEN TAKEN OVER BY MAN'S EXPANSION OF THE MODERN WORLD.
NOW MODERN SCIENCE MOVES TO PREVENT FURTHER DECLINE IN THE NUMBERS OF
SUCH OTHER LIVING THINGS AND INDEED TO EXPAND THEIR NUMBERS AND TO
RAPIDLY INCREASE THEIR RANGE OF LOCATIONS.
THE ACCOMPANYING PICTURE COULD HAVE SEEN IN THE PAST, BUT IT WOULDN'T
HAVE CONTAINED THE SURPRISE IT DOES TODAY. BABY ZEBRA AMO IS STANDING
BESIDE HER SURROGATE MOTHER, MAHOGANY -- A WELSH PONY MARE! THIS ZEBRA
FOAL, THE FIRST OF A KIND IN BRITAIN AND ONLY THE SECOND IN THE WHOLE
WORLD, WAS BORN AS A RESULT OF AN EMBRYO TRANSPLANT!
THIS EXTRA-SPECIES PREGNANCY IS THE RESULT OF COLLABORATION BY THE
ZOOLOGICAL SOCIETY OF LONDON'S INSTITUTE OF ZOOLOGY AND THE THOROUGHBRED
BREEDERS' ASSOCIATION EQUINE FERTILITY UNIT AT CAMBRIDGE. BOTH GROUPS
ARE DEDICATED TO CONSERVING RARE SPECIES FROM EXTINCTION.
UTILIZING A NON-SURGICAL TECHNIQUE OF FLUSHING THE UTERUS WITH EMBRYO
CULTURE MEDIUM, THESE SCIENTISTS LOCATED AND THEN EXTRACTED A ZEBRA
EMBRYO, ONLY HALF A MILLIMETRE (FRACTION OF AN INCH) IN DIAMETER AND
CONTAINING ONLY 100 CELLS. THIS WAS TAKEN FROM THE GRANT'S ZEBRA MARY,
JUST EIGHT DAYS AFTER MATING WITH A GRANT'S STALLION NAMED JEFF. WITHIN
FOUR HOURS THE EMBRYO WAS TRANSFERRED TO THE SURROGATE MOTHER IN A
NEARBY TOWN, WHOSE OESTROUS CYCLE HAD BEEN SYNCHRONIZED TO THE ORIGINAL
"MOTHER" BY AN INJECTION OF THE HORMONE PROSTAGLANDIN.
EMBRYO TRANSPLANTS FIRST GAINED FAME WHEN THEY PROVIDED A RAPID METHOD
OF INCREASING CATTLE HERD QUALITY AND QUANTITY AT LOWER COST. NOW THIS
ACCEPTED METHOD IS BEING USED TO RE-ESTABLISH MANY TYPES OF ENDANGERED
SPECIES.
DR. PHIL SUMMERS, WHO LED THE WORK AT THE LONDON ZOO, HAS ALSO WORKED
WITH THE RARE PRZEWALSKI WILD HORSE. FOUR SUCH FOALS HAVE BEEN BORN VIA
THIS METHOD DURING THE LAST TWO YEARS. IT IS POSSIBLE TO RECOVER EMBRYOS
FROM OTHER RARE SPECIES FOR TRANSFER TO THE UTERI OF DOMESTIC HORSES OR
DONKEYS.
THERE IS MORE TO THIS RESEARCH THAN SAVING A SPECIES FROM EXTINCTION.
SUCH DEVELOPMENTS CONTRIBUTE TO THE WHOLE STUDY OF EARLY PREGNANCY LOSS,
A FAIRLY COMMON OCCURENCE IN THOROUGHBRED MARES. THIS IS IMPORTANT, AS
REJECTION WHICH MIGHT BE EXPECTED AS A TYPE OF IMMUNOLOGICAL REACTION
BETWEEN SPECIES, CAN NOW, TO A CERTAIN EXTENT, BE CONTROLLED.
AMO'S REAL ZEBRA MOTHER MARY IS NOW CARRYING ANOTHER FOAL HERSELF.
WHEN THIS BABY IS DELIVERED, AMO WILL HAVE A FULL BROTHER OR SISTER BORN
ABOUT TWO MONTHS AFTER HER OWN ARRIVAL.
RARE HUMAN SPECIES COULD ALSO BE SAVED BY THE SAME TECHNIQUES.
MORE INFORMATION:
JOAN CRAMMOND,
LONDON ZOO,
REGENT'S PARK, LONDON NW1 4RY, ENGLAND.
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