Biologists in Japan have cloned 581 mice from one original donor mouse, Livescience reported. The scientists made the mice over 25 generations of cloning; that is, from making clones from clones from clones, 25 times over. 根据 Livescience的报道，日本生物学家用一只小鼠的基因供体克隆出 581只小鼠。这些科学家们克隆了 25代小鼠，即：用克隆鼠克隆新的小鼠，一共克隆了 25次。
They could probably make animal clones indefinitely, the research team wrote in a paper published last week in the journal Cell Stem Cell. 研究团队在上周发表在《干细胞》期刊中的论文称，他们很有可能会让动物无休无止地克隆下去。
Really. Check out the last sentence of their abstract:" Our results show that repeated iterative recloning is possible and suggest that, with adequately efficient techniques, it may be possible to reclone animals indefinitely." 是这样吗？我们来看看论文摘要的最后一句话：“我们的研究结果证明多代克隆是可能实现的。如果技术到位，那么克隆出无穷多代的动物都是可能的。”
The 581 cloned mice were made using an improved version of somatic cell nuclear transfer, the technique that created Dolly the cloned sheep in 1996. 这 581只小鼠是用改进后的体细胞克隆技术克隆得到的，这一技术最早是在 1996年克隆多莉时发明的。
Previously, researchers using somatic nuclear cell transfer would get fewer and fewer animals every time they tried to make a clone from a clone. Eventually, they wouldn't get any new clones at all. Cloned mammals also often died sooner than their non-cloned counterparts. 在此之前，运用体细胞克隆技术反复克隆动物时，被克隆的动物数量会越来越少，直到最终无法克隆出新动物为止。被克隆出的哺乳动物也会比非克隆的同类动物死得更早。
The cloning team protected the mice's DNA from the genetic abnormalities they( the humans) think reduced the efficiency of previous cloning efforts. The researchers didn't lose any cloning efficiency over their 25 generations, they reported, and their cloned mice lived normal lifespans of about two years. 这支研究团队保护了小鼠的基因，使其不发生基因异常。他们认为，基因异常正式降低克隆形成率的罪魁祸首。研究者称，这 25代小鼠的克隆过程中克隆形成率并没有降低，小鼠的寿命也很正常，约能生存两年时间。
Cloning could help reproduce animals for farming or conservation, Sayaka Wakayama, a biologist at the RIKEN Center for Developmental Biology who led the cloning study, said in a statement. 日本理化研究所的生物学家若山清香是这次研究的负责人，他在一个声明中提到，克隆技术可以繁殖动物，为农业和动物保护服务。
This isn't the first time Wakayama has made some big strides in cloning. He previously cloned mice from bodies of mice that had been frozen for 16 years. 这已经不是若山清香在克隆技术上的第一个重大成就了。此前他曾经以一只冰冻了 16年的小鼠为供体克隆出了一只小鼠。
