Effective individual culture system for in vitro production of bovine embryos

Abstract

A new and effective protocol to culture bovine embryos without coculture and with individualized culture media has been established, which would allow the study of a single embryo’s metabolism. For this purpose, bovine embryos were produced in vitro by standard protocols in three different types of media: KSOM, SOFaa, and KSOM followed by SOFaa at day 2. Presumptive zygotes were divided into six groups: control, cultured in groups (C-KSOM, C-SOFaa, and C-KS), and individual well system (W-KSOM, W-SOFaa, and W-KS). Cleavage and blastocyst rates were assessed on days 2 and 7 respectively. Relative quantification of transcripts related to important metabolic processes (GLUT1, GLUT3, GSK3, SOD1, HSPD1, G6PD) were assessed in C-KS and W-KS blastocysts. Results show that cleavage was significantly higher only in W-KSOM when compared to C-KSOM, while blastocyst rates differ only between C-SOF and W-SOF. All the other comparisons did not present statistical difference. Moreover, gene expression analysis revealed that blastocysts cultured in groups and in the individual well system present similar transcription patterns. Thus, the obtained conclusion was that the individual well system performed could be used as an effective alternative protocol for individual culture of bovine embryos, since the rates are similar to routine group culture.