Westhusin's experience with cloning animals leaves him upset by all this talk of human cloning. In three years of work on the Missy project, using hundreds upon hundreds of dog's eggs, the A&M team has produced only a dozen or so embryos (胚胎) carrying Missy's DNA. None have survived the transfer to a surrogate (代孕的) mother.
The wastage of eggs and the many spontaneously aborted fetuses (胎) may be acceptable when you're dealing with cats or bulls, he argues, but not with humans.
