Lanza R P, Cibelli J B, Diaz F, Moraes C T, Farin P W, Farin C E, Hammer C J, West M D, Damiani P
Advanced Cell Technology, One Innovation Drive, Worcester, MA 01605, USA.
Cloning. 2000;2(2):79-90. doi: 10.1089/152045500436104.
Approximately 100 species become extinct a day. Despite increasing interest in using cloning to rescue endangered species, successful interspecies nuclear transfer has not been previously described, and only a few reports of in vitro embryo formation exist. Here we show that interspecies nuclear transfer can be used to clone an endangered species with normal karyotypic and phenotypic development through implantation and the late stages of fetal growth. Somatic cells from a gaur bull (Bos gaurus), a large wild ox on the verge of extinction, (Species Survival Plan < 100 animals) were electrofused with enucleated oocytes from domestic cows. Twelve percent of the reconstructed oocytes developed to the blastocyst stage, and 18% of these embryos developed to the fetal stage when transferred to surrogate mothers. Three of the fetuses were electively removed at days 46 to 54 of gestation, and two continued gestation longer than 180 (ongoing) and 200 days, respectively. Microsatellite marker and cytogenetic analyses confirmed that the nuclear genome of the cloned animals was gaurus in origin. The gaur nuclei were shown to direct normal fetal development, with differentiation into complex tissue and organs, even though the mitochondrial DNA (mtDNA) within all the tissue types evaluated was derived exclusively from the recipient bovine oocytes. These results suggest that somatic cell cloning methods could be used to restore endangered, or even extinct, species and populations.
每天约有100个物种灭绝。尽管人们对利用克隆技术拯救濒危物种的兴趣与日俱增，但此前尚未有成功的种间核移植的报道，仅有少数关于体外胚胎形成的报告。在此，我们表明种间核移植可用于克隆濒危物种，使其通过植入和胎儿生长后期实现正常的核型和表型发育。来自印度野牛（Bos gaurus）公牛的体细胞，印度野牛是一种濒临灭绝的大型野牛（物种生存计划中不足100头），与来自家牛的去核卵母细胞进行电融合。12%的重构卵母细胞发育到囊胚阶段，当将这些胚胎移植到代孕母体时，其中18%发育到胎儿阶段。在妊娠46至54天时，选择性地取出了3个胎儿，另外两个分别持续妊娠超过180天（仍在进行）和200天。微卫星标记和细胞遗传学分析证实，克隆动物的核基因组起源于印度野牛。结果表明，印度野牛的细胞核能够指导正常的胎儿发育，分化形成复杂的组织和器官，尽管在所评估的所有组织类型中的线粒体DNA（mtDNA）完全来自受体牛卵母细胞。这些结果表明，体细胞克隆方法可用于恢复濒危甚至灭绝的物种及种群。
