Successful implantation of in vitro cultured rabbit embryos after uterine transfer: a role for mucin.
The functional role of the mucin layer for development of rabbit embryos was examined by uterine transfer of embryos with different thicknesses of mucin. Embryos collected at various intervals after human chorionic gonadotropin (hCG) injection were cultured until 90 hr post-coitum (p.c.) and transferred to the uterus of synchronized recipients. When embryos collected at 20 or 25 hr p.c. were used for transfer, no implantation occurred. By contrast, embryos collected at 35 or 40 hr p.c. developed to term at high rates (53 and 80%, respectively). The thickness of the mucin layer on the embryos was different between these two groups. Embryos collected before 25 hr p.c. have less than 11.2 +/- 0.2 microns of thickness of mucin and embryos collected after 35 hr p.c. have more than 34.3 +/- 5.5 microns. To examine whether mucin deposition is required for in vitro cultured rabbit blastocysts to continue development after uterine transfer, embryos were collected at 20 hr p.c., cultured for 60 or 70 hr in vitro, and then temporarily transferred to the oviducts of recipient does to add mucin. These embryos were recovered from the oviducts at 24 hr after transfer, classified according to the thickness of mucin deposition, and transferred again to the uterus of synchronized recipients. Twenty live young were obtained from 67 embryos with a 20-40 microns thick mucin layer. No live young were obtained from 57 embryos with less than a 20 microns thick mucin. The thickness of the mucin layer appears to be an important factor for successful implantation of rabbit embryos.
Murakami
H
H
Laboratory of Reproductive Biochemistry, National Institute of Animal Industry, Ibaraki, Japan.
Imai
H
H
D000818:Animals; D001755:Blastocyst; D004624:Embryo Transfer; D005260:Female; D066298:In Vitro Techniques; D009077:Mucins; D011247:Pregnancy; D011817:Rabbits; D014599:Uterus / Q000033:anatomy & histology / Q000378:metabolism
D009077:Mucins