RESUMEN
Conjugated linoleic acids (CLA) are employed to overcome the bovine periparturitional negative energy balance. Especially of interest are trans10,cis12 -linoleic acid (t10c12-CLA) and cis9,trans11-linoleic acid (c9t11-CLA). Their impact on embryonic development, though, is not clear. Here, effects of both above-mentioned CLA on bovine in vitro-produced embryos were assessed. Zygotes (n=2098) were allocated to one of seven groups: cultured with 50 or 100µM of either c9t11-CLA or t10c12-CLA, with 14 or 28mM DMSO or without supplement (control). Messenger RNA analysis of target gene transcripts (IGF1R, IGFBP2, IGFBP4, CPT2, ACAA1, ACAA2, FASN, SCD) via RT-qPCR was performed in single blastocysts. Cleavage rates did not differ, whereas development rates were decreased in both t10c12-supplemented groups in comparison to the unsupplemented group (31.7% ±2.2 control vs 20.2% ±2.0 50µM t10c12 vs 21.0% ±2.8 100µM t10c12). Compared with the unsupplemented group, SCD was expressed at a lower level in embryos cultured with 50µM c9t11-CLA. The relative amount of several transcripts was increased in embryos cultured with 14mM DMSO in comparison to those that developed in the presence of 50µM t10c12-CLA (IGFBP2, ACAA1, CPT2, FASN, SCD) or 50µM c9t11-CLA (IGF1R, IGFBP2, ACAA1, CPT2, FASN, SCD). The molecular analyses show that CLA influence embryonic fat metabolism.