High developmental potential in vitro and in vivo of cattle embryos cloned without micromanipulators.
OBJECTIVE
In order to simplify cloning, a new method that does not require micromanipulators was used. We aimed to evaluate the developmental potential of two bovine cell lines upon cloning.


METHODS
In vitro matured bovine oocytes, were released from zona pellucida, enucleated, fused to foetal or adult somatic donor cells. The reconstructed embryos were reprogrammed, activated and cultured until blastocyst stage. No micromanipulators were used. Blastocyst rate and quality was scored. Some expanded (d7) blastocysts were transferred to recipient cattle and collected back at d17 to assess elongation.


RESULTS
High developmental potential in vitro of cloned embryos to expanded (d7) blastocysts was achieved (52.6%). In one cell line, 65.7% of blastocysts was scored. Most blastocysts (87.4%) were graded as excellent. In vivo development to elongation (day-17) in temporary recipient cows also showed a high developmental potential (11/18 transferred blastocysts elongated).


CONCLUSIONS
Hand-made cloning is an efficient alternative for cloning in cattle.
Rodríguez
Lleretny
L
Animal Science, University of Concepcion, Avenida Vicente Méndez 595, Chillán, 537, Chile.
Navarrete
Felipe I
FI
Tovar
Heribelt
H
Cox
José F
JF
Castro
Fidel Ovidio
FO
D000818:Animals; D001755:Blastocyst / Q000166:cytology; D002417:Cattle / Q000196:embryology*; D002478:Cells, Cultured; D003001:Cloning, Molecular; D004624:Embryo Transfer; D004622:Embryo, Mammalian / Q000166:cytology*; D005260:Female; D066298:In Vitro Techniques; D008846:Micromanipulation; D053652:Nuclear Transfer Techniques; D009865:Oocytes / Q000166:cytology / Q000502:physiology*