Effect of oxygen tension, culture media and growth factors on in vitro development of porcine somatic cloned embryos

Chino. 建立高效的猪体细胞克隆胚胎的体外培养体系。比较了克隆胚胎体外培养过程中高、低氧分压（20% O2和7% O2）和2种培养基（NCSU-23和 PZM-3）及添加表皮生长因子（EGF）和碱性成纤维促进因子（bFGF）对胚胎的囊胚发育率及囊胚细胞数的影响。（1）与高氧（20% O2）气相相比，低氧（7% O2）条件下NCSU-23显著提高了胚胎的囊胚率和细胞数（P＜0.05，13.7% vs. 8.2%；46.3 vs.31.0），培养基PZM-3只能显著提高囊胚细胞数（P＜0.05，49.4 vs. 36.6）；（2）与NCSU-23相比，PZM-3无论在高氧还是低氧条件，囊胚率和囊胚细胞数都较高；（3）NCSU-23中添加10 ng•ml－1 EGF或bFGF对胚胎的囊胚发育率（P＜0.05，25.5%，31.7% vs. 15.1%）有显著提高，但不能提高囊胚细胞数。低氧条件有利于胚胎的早期发育；PZM-3无论在高氧还是低氧条件下，都是胚胎发育的一个效果稳定、高效的培养基；胚胎培养基中添加EGF或bFGF能提高胚胎的囊胚发育率。

Inglés. This research focused on establishing a more efficient in vitro culture system for porcine somatic cell nuclear transfer (SCNT) embryos. Systematical study had been carried on effect of oxygen tension（20% O2 and 7% O2）, culture media (NCSU-23 and PZM-3) and growth factors (EGF, bFGF) on in vitro development of porcine SCNT embryos, including blastocyst formation rate and cell number per blastocyst. In experiment 1, Compared with 20% O2, NCSU-23 in low oxygen (7% O2) greatly improved the blastocyst rate and cell number of cloned embryos（P＜0.05, 13.7% vs. 8.2%; 46.3 vs. 31.0）.Cloned embryos in PZM-3 and 7 % O2 only had a greater cell number (P＜0.05, 49.4 vs. 36.6). Compared with NCSU-23, PZM-3 supported a higher blastocyst rate, regardless of atmosphere. In experiment 2, 2-4 cell stage cloned embryos cultured in NCSU-23 supplemented with 10 ng•ml-1 EGF or bFGF had a significantly greater developmental ability to blastocyst than the control (P＜0.05, 255%，31.7% vs. 15.1%). Low oxygen atmosphere improved blastocyst rate and total cell number; Regardless of atmosphere, PZM-3 supported a higher development rate and quality of porcine SCNT embryos. EGF and bFGF may be necessarily beneficial to the blastocyst formation.