遗传背景对小鼠四倍体胚胎发育的影响

Influence of Mouse Genetic Background on Developmental Potential of Tetraploid Embryo

不同遗传背景的小鼠2-细胞期胚胎经过电融合后,胚胎的融合效率和四倍体胚胎的发育能力存在着一定的差异。本试验采用C57(C57×C57)、ICR(ICR×ICR)、BALB/c(BALB/c×BALB/c)、B6D2F2(B6D2F1×B6D2F1)、B6C3D2F2(B6C3F1×B6D2F1)品系的二倍体2-细胞期胚胎在相同的条件下经过电融合处理,结果表明:小鼠四倍体胚胎的获得效率受小鼠遗传背景的影响,远交系小鼠胚胎B6D2F2和B6C3D2F2的融合率显著高于近交系C57,ICR和BALB/c(P<0.05);四倍体胚胎在体外的发育情况也受其遗传背景的影响,在桑椹胚发育率和囊胚发育率上B6D2F2和B6C3D2F2品系的四倍体胚胎都显著高于C57和BALB/c品系的四倍体胚胎(P<0.05);杂合和纯系遗传背景的小鼠四倍体胚胎囊胚细胞数目相比具有显著差异(P<0.05或P<0.01);不同遗传背景的小鼠四倍体胚胎着床率间不存在显著差异(P>0.05);杂合背景的小鼠四倍体胚胎得到5只发育至13.5dpc(dayspostcoitum,dpc)的胎儿,纯合背景的小鼠四倍体胚胎得到0只发育至11dpc的胎儿。

Developmental potential and electrofusion rate are different among mice genetic backgrounds after electrofusimg diploid blastomeres at 2-cells stage. In this study, mice diploid blastomeres a）2-cells stage with different genetic backgrounds （C57, ICR, BALB/c, B6D2F2, B6C3D2F2） were electrotused in the same condition. The results showed： electrofusion rate and developmental potential of tetraploid embryos with hybrid genetic background were higher than that of with inbred and outbred genetic （P 〈 0. 05）. Tetroploid blastocysts with high heterozygosity contained much more cells compared to those with low heterozygosity （P 〈 0. 05 or P 〈 0. 01 ）. The post-implantation rates of tetraploid blastocysts with different genetic background were not significant （ P 〉 0. 05 ）, but those with high heterozygosity can survive longer time. 5 fetus from mice tetraploid embryos with hybrid genetic background which developed to 13.5 dpc（ days post coitum, dpc） were obtained, while no fetus could develop to 11.0 dpc from those with houmzygous genetic background.