Comparison Of Mouse Embryo Development By Co-Culturing With Ampullary And Isthmic Epithelical Cell Of Hamster Oviduct And The Effect Of Injected Gonadotropins

Introduction: in this study we examined the effect of ampullary and isthmic epithelial cell of golden hamster oviduct on N-Mary mouse embryo development during 4-days in vitro co - culture, and the effect of injected gonadotropins on the quality of co-culture.
Materials and methods: Golden hamster oviducts were isolated 18-24h after treating the hamster with HCG. They were flushed with DMEM / Ham’s F - 12+FCS %10. According to presence of cumulus mass, the oviducts were classified into two categories: (i) responding to gonadotropins which contained cumulus mass, and (ii) non - responding to gonadotropins, which showed cumulus mass. Using collagenase ampullary (A) and isthmic (I) epithelial cells from each category were isolated and cultured in medium. A monolayer culture system of hamster oviducts were estabilished. The late, 2- cell N-MARY mouse embryos were cultured for 4- days with T6 + FCS %10 on the monoalyers (A-I) and T6 + GCS. 10% as control group (C) in each category. Results: (i) After 96h hatching blastocyst in A, I and C were 64% , 50% and 36% respectively, which, significantly higher in co-culture groups (p<0.001 for A , p<0.05 for I).In addition during first 24h, embryo development in ampullary co - culture was better than isthmic co-cultures specially in ampulla (p<0.001 for A and p<0.05 for comparison of A and I) (ii) After 96h ,more embryos developed to blastocyst in C group than A and I groups, (C= %58, A= %20, I=%27,p<0.001)
Conclusion: Hamster oviduct epithelial cells which are specialized cells from ampullary region could improve the development of embryos from other species and this is greatly affected by response of hamster to gonadotropins.