Indistinguishable transcriptional profiles between in vitro- and in vivo-produced bovine fetuses

During the past several decades, in vitro fertilization (IVF) has been increasingly used both in animal production and human infertility treatment. Animals derived from in vitro manipulation are occasionally associated with abnormal offspring syndrome (AOS) and other developmental abnormalities. By studying gene expression of in vitro-produced (IVP) embryos/animals, we gain an indicator of how well this procedure mimics the in vivo environment. Most previous studies of this nature have focused on only a few genes at a time or have been limited to studying the pre-implantation stage; a global view of how gene transcription may be influenced by in vitro procedures during fetal development has yet to be ascertained. To this end, we collected liver and placental tissue samples from IVP and in vivo control bovine fetuses at days 90 and 180 of gestation. We used a bovine 13K oligonucleotide microarray to investigate the transcriptional profiles in both tissues from IVP fetuses, and compared them with those of their age-matched in vivo counterparts. Surprisingly, in both liver and placental tissues, the transcriptional profiles between IVP and control fetuses, at either 90 or 180 days of gestation, were indistinguishable. A total of 879 genes were found to be significantly regulated during liver development from 90 to 180 days of gestation, but there were no gene expression changes in the placental tissue during this developmental period. Quantitative real-time RT-PCR on 11 selected genes confirmed these results. Our results have certain implications for IVF technologies, both in agriculture and in human medicine.