阅读理解。
With only about 1,000 pandas left in the world, China is desperately trying to clone the animal and save these in a dangerous situation. That's a move similar to what a Texas A & M University researchers have been undertaking for the past five years in a project called "Noah's Ark".
Noah's Ark is aimed at collecting eggs, embryos(胚胎), semen and DNA of these animals and storing them in liquid nitrogen. If certain species should become extinct, Dr. Duane Kraemer, a professor in Texas A & M's College of Veterinary, Medicine, says there would be enough of the basic building blocks to reintroduce the species in the future.
It is estimated that as many as 2, 000 species of mammals, birds and reptiles will probably become extinct in over 100 years. The panda, native only to China, is in danger of becoming extinct in the next 25 years.
This week, Chinese scientists said they grew an embryo by introducing cells from a dead female panda into the egg cells of a Japanese white rabbit. They are now trying to implant the embryo into a host animal.
The entire procedure could take from three to five years to complete.
"The nuclear transfer of one species to another is not easy, but the lack of available panda eggs could be a major problem," Kraemer believes. "They will probably have to do several hundred transfers to result in one pregnancy (having a baby). It takes a long time and it's difficult, but this could be groundbreaking science if it works. They are certainly not putting any live pandas at risk, so it is worth the effort," adds Kraemer, who is one of the leaders of the Project at Texas A&M, the first-ever attempt at cloning a dog.
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