Search Results

You are looking at 1 - 1 of 1 items for

  • Author: Y. Takuma x
  • Refine by access: All content x
Clear All Modify Search
K. Goto
Search for other papers by K. Goto in
Google Scholar
PubMed
Close
,
N. Iwai
Search for other papers by N. Iwai in
Google Scholar
PubMed
Close
,
K. Ide
Search for other papers by K. Ide in
Google Scholar
PubMed
Close
,
Y. Takuma
Search for other papers by Y. Takuma in
Google Scholar
PubMed
Close
, and
Y. Nakanishi
Search for other papers by Y. Nakanishi in
Google Scholar
PubMed
Close

In this study, the quality (number of cells) and pregnancy rates of bovine blastocysts produced by in vitro maturation/in vitro fertilization (IVM/IVF) following cultivation in either cell-free culture or co-culture were compared. Bovine one-cell IVM/IVF embryos obtained 6 h after insemination were stripped of cumulus cells and assigned to either cell-free culture or co-culture with granulosa cell monolayers for 9 days (Expt 1) or 10 days (Expts 2 and 3). In Expt 3, day-7 (day 0 = day of insemination) blastocysts, day-8 expanded blastocysts and day-9 hatched blastocysts were air-dried, fixed and stained to determine the number of cells. Expanded blastocysts obtained in Expt 1 were cryopreserved using propylene glycol as a cryoprotectant and were used later for embryo transfer. There were no significant differences between cell-free culture and co-culture in the percentage of one-cell embryos that developed to 2- to 16-cells (66.7% versus 72.4% for Expt 1, 71.0% versus 78.2% for Expt 2). However, significantly more (P<0.05) of the one-cell embryos co-cultured with granulosa cell monolayers developed to morula, blastocyst and expanded blastocyst stages compared with those in cell-free culture (35.0 versus 27.1%, 25.1 versus 14.2%, 15.6 versus 5.4% for Expt 1; 37.6 versus 24.0%, 25.7 versus 11.0%, 16.8 versus 3.0% for Expt 2). Only embryos co-cultured with granulosa cell monolayers hatched (Expt 2). Embryos co-cultured with granulosa cell monolayers also had higher (P<0.01) numbers of cells (92 ± 42 versus 56 ± 21 for blastocysts, 149 ± 53 versus 81 ± 29 for expanded blastocysts). Pregnancy rates tended to be higher for embryos produced by co-culture compared with those from cell-free culture (40.0 versus 27.3%, respectively). The results suggest that embryos produced in cell-free culture were of poorer quality than those produced in co-culture; however, some of them were developmentally competent as confirmed by the births of three calves after transfer to eleven recipient cows.

Free access