Wagner Stefan, Cullum Alison, Wells David N, Laible Götz
1 AgResearch Limited, Ruakura Research Centre , Hamilton, New Zealand .
2 Current address: Rowett Institute , Aberdeen, United Kingdom .
Cell Reprogram. 2017 Dec;19(6):331-336. doi: 10.1089/cell.2017.0018. Epub 2017 Oct 11.
Somatic cell nuclear transfer (SCNT), commonly referred to as cloning, results in the generation of offspring that, except for mitochondrial DNA, are genetically identical to the nuclear donor. We previously used a genetically modified bovine cell line as the donor for SCNT and obtained a calf, named Daisy, that was born without a tail. To determine whether the missing tail was a result of the genetic modification, we performed recloning experiments by using either cells from a sacrificed pregnancy of a second clone (Daisy's "twin" clone) or cells from tailless Daisy as donors for SCNT. Cloned fetuses from aborted pregnancies and a cloned live calf that died shortly after birth were examined and confirmed to all possess tails. Hence, the observed phenotype of Daisy's lacking tail is not due to the introduced transgene or a mutation present in the cell that was used for her production. Rather, the missing tail has most likely arisen from an epigenetic reprogramming error during development.
体细胞核移植（SCNT），通常称为克隆，可产生除线粒体DNA外与核供体基因完全相同的后代。我们之前使用一种基因改造的牛细胞系作为SCNT的供体，并获得了一头名为黛西的小牛，它出生时没有尾巴。为了确定尾巴缺失是否是基因改造的结果，我们通过使用来自第二个克隆（黛西的“双胞胎”克隆）流产妊娠的细胞或来自无尾黛西的细胞作为SCNT的供体进行了再克隆实验。对流产妊娠的克隆胎儿和出生后不久死亡的克隆活小牛进行了检查，证实它们都有尾巴。因此，观察到的黛西无尾表型并非由于导入的转基因或用于其生产的细胞中存在的突变。相反，尾巴缺失很可能是发育过程中表观遗传重编程错误导致的。
