Kräusslich H, Brem G
Tierarztl Prax Suppl. 1985;1:50-7.
An important contribution to genetic and embryonic engineering in mammalian embryos is the production of chimeric mammals. Chimeras can be produced by aggregating the blastomeres of two different embryos to make a single individual. A method is described to produce bovine chimeras by aggregating non-surgically collected embryos of different breeds and transferring the aggregated embryos nonsurgically to synchronised recipients. An overt chimeric bull calf (Holstein-Friesian and Brown-Swiss) was born on March 31st, 1984. Chimeras have many uses in research, but one practical use is to rescue defective embryos that would not develop to term on their own. Such embryos can be aggregated with normal blastomeres to produce a chimera. Some of the initially defective cells can even become part of the germ line in the chimera and give rise to perfectly normal eggs or sperm. Two models for using this technique in cattle research are described. The lethal disorder arachnomelie has a rather high frequency in some German Brown-Swiss populations. Chimeric calves developing from embryos descending of carrier matings could help to find out the genetic and developmental background of this disorder. Chimeras produced of transgenic teratocarcinoma cell lines and normal embryos offer one possibility to produce transgenic cattle. The advantages and disadvantages of these possibilities are discussed.
嵌合体哺乳动物的产生是对哺乳动物胚胎基因工程和胚胎工程的一项重要贡献。嵌合体可以通过将两个不同胚胎的卵裂球聚集在一起形成一个个体来产生。本文描述了一种通过聚集不同品种的非手术采集胚胎并将聚集后的胚胎非手术移植到同步受体中来生产牛嵌合体的方法。一头明显的嵌合体公牛犊（荷斯坦 - 弗里生牛和瑞士褐牛）于1984年3月31日出生。嵌合体在研究中有许多用途，但一个实际用途是挽救那些自身无法发育至足月的缺陷胚胎。此类胚胎可以与正常卵裂球聚集以产生嵌合体。一些最初有缺陷的细胞甚至可以成为嵌合体生殖系的一部分，并产生完全正常的卵子或精子。本文描述了在牛研究中使用该技术的两种模型。致死性疾病蛛状肢畸形在一些德国瑞士褐牛群体中具有相当高的发生率。由携带致病基因交配所产生胚胎发育而来的嵌合体小牛有助于查明这种疾病的遗传和发育背景。由转基因畸胎瘤细胞系和正常胚胎产生的嵌合体提供了一种生产转基因牛的可能性。本文讨论了这些可能性的优缺点。
