A simplified procedure for making reconstituted blastocysts for interspecific and intergeneric transfer
Rorie, R.W.; Pool, S.H.; Prichard, J.F.; Betteridge, K.J.; Godke, R.A.
Veterinary Record 135(8): 186-187
1994
ISSN/ISBN: 0042-4900 PMID: 7992478 Document Number: 438979
Suffolk-Louisiana native crossbred ewes were used as embryo donors and Nubian-French Alpine crossbred females as either embryo donors or recipients. Sheep inner cell mass (ICM) cells were immunosurgically isolated from hatched blastocysts. Using a simplified microsurgical procedure, a microsurgical blade was inserted vertically into a goat blastocyst to separate the ICM from the blastocyst cavity, the sheep ICM was deposited against the inner wall of the goat blastocyst before the blade was used to severe the goat IVM from the reconstituted embryo. Nine reconstituted blastocysts were transferred 3 at a time to 3 recipient female goats. One recipient returned to oestrus and 2 recipients were confirmed pregnant at 60 days. One pregnant female lost its single fetus before term but the third produced 2 apparently normal lambs with no outward signs of chimaerism. In contrast 2 overtly intergeneric chimaeras were born to a female goat following transfer of good blastocysts similarly injected with sheep ICMS but without the excision of goat ICM. Transfer of 4 of the excised goat ICMS to one female resulted in the birth of 2 kids. This simple and efficient micromanipulation technique should be useful for producing reconstituted blastocysts capable of developing into full-term offspring after interspecific or intergeneric transfer.