作者研究了用基因打靶造成血小板生成素受体编码基因缺陷后小鼠的造血状况。 首先,在体外构建成带β-gal-含PGKneo的暗盒并以此置换c-mpl外显子1～5的核苷酸序列位置,将c-mpl基因组DNA3′末端8.3kb的Hind Ⅲ片段连接到β-gal-PGRneo基因的3′端,从而形成c-mpl基因的打靶载体(14.5kb),酶切分离后得到14.5kb的打靶基因片 The authors investigated the hematopoietic status of mice after genetic target knockdown of thrombopoietin receptor-encoding genes. First, a cassette containing β-gal-PGKneo was constructed in vitro and the nucleotide sequence positions of c-mpl exons 1 to 5 were replaced thereby, and a HindIII fragment of 8.3 kb at the 3 ’end of the c-mpl genomic DNA To the 3 ’end of the β-gal-PGRneo gene to form a targeting vector (14.5 kb) of the c-mpl gene, which resulted in a 14.5 kb target gene fragment