This is an older article (I think I need new glasses) but still has interesting information. – Debbie
5 cloned foals (photo: Texas A & M)
SOURCE: THE HORSE
Equine Cloning: Where are we today?
“Five years ago, presenting ‘A Review of Cloning’ in the horse was almost unimaginable,” began Katrin Hinrichs, DVM, PhD, professor of veterinary physiology and pharmacology and Patsy Link Chair in reproductive studies at Texas A&M University. “But the field has taken off very quickly, partly because of advances in other species.”…
…Hinrichs offered the following timeline of cloning milestones:
2000: The first equine nuclear transfer embryo, with five cells, was produced.
2002: Woods, et al., announced cloned mule pregnancies at the 8th International Equine Reproduction Symposium.
2003: Three mules cloned from fetal cells were born through the efforts of the University of Idaho and Utah State University. Their DNA came from an embryo that was a full sibling to a famed racing mule.
Also in 2003, one foal cloned from adult cells was born in Italy. The mare that carried the foal to term was the same mare from which donor cells were taken, so she essentially carried her identical twin to term.
2005: The Italian research group announced the birth of a second cloned horse, and another died at about 48 hours of age from septicemia. Two cloned horses were born in Texas–the third and fourth live cloned foals.
“Italy got one live foal from nine pregnancies resulting from 101 embryo transfers,” reported Hinrichs. “Texas A&M got two live foals from three pregnancies out of 11 embryos transferred. Why such a difference? Both labs had only about 5% blastocyst rate (survival of the cloned embryos to the early blastocyst stage), so the difference is in the quality of the blastocysts.”
2006: Texas A&M announced the births of seven viable cloned foals. From one donor, 13 embryo transfers resulted in nine pregnancies and five cloned foals. The sixth and seventh foals were from two other donors.
Also in 2006, the commercial company ViaGen announced the birth of three live cloned foals.
“So we know cloning is possible, and that its efficiency varies by the laboratory,” Hinrichs summed up. “Unfortunately, there are currently only two labs I know of working on equine cloning–Texas A&M and ViaGen. With that little amount of work being done, it will be very hard to see what protocols affect the health of foals.”
READ THE ENTIRE ARTICLE HERE.