The Effect of Simulated Physiological Oocyte Maturation (SPOM) and L-Carnitine  on Bovine Oocyte Developmental Competence

Ali  Malekpour; Abolfazl  Shirazi; Sara Borjian  Boroujeni; Ali  Sarvari; Mohammad Mehdi  Naderi; Mostafa  Pournourali; Bahareh  Behzadi; Mohammad Mehdi  Mehrazar

doi:10.18502/ajmb.v16i4.16742

Ali Malekpour Department of Embryology and Andrology, Avicenna Research Institute ACECR, Tehran, Iran
Abolfazl Shirazi Department of Embryology and Andrology, Avicenna Research Institute ACECR, Tehran, Iran
Sara Borjian Boroujeni Department of Embryology and Andrology, Avicenna Research Institute ACECR, Tehran, Iran
Ali Sarvari Department of Embryology and Andrology, Avicenna Research Institute ACECR, Tehran, Iran
Mohammad Mehdi Naderi Department of Embryology and Andrology, Avicenna Research Institute ACECR, Tehran, Iran
Mostafa Pournourali Department of Embryology and Andrology, Avicenna Research Institute ACECR, Tehran, Iran
Bahareh Behzadi Department of Embryology and Andrology, Avicenna Research Institute ACECR, Tehran, Iran
Mohammad Mehdi Mehrazar Department of Embryology and Andrology, Avicenna Research Institute ACECR, Tehran, Iran

DOI: https://doi.org/10.18502/ajmb.v16i4.16742

Keywords: 3-Isobutyl-l-methylxanthine, bcl-2-associated X protein, Blastocyst, Carnitine, Cattle, Meiosis, Oo-cytes, Pre-IVM

Abstract

Background: Simulated Physiological Oocyte Maturation (SPOM) mimics in vitro the physiological events of oocyte maturation in the presence of cAMP modulators. These modulators increase the intracellular concentrations of cAMP, which inhibits the immediate resumption of meiosis and gives the oocyte more time to gain optimal developmental competence. In addition, L-carnitine helps to increase the energy supply of cells through the β-oxidation of fatty acids. This study aimed to investigate the effect of SPOM and L-carnitine supplementation during In Vitro Maturation (IVM) and In Vitro Culture (IVC) on the developmental competence of bovine oocytes.

Methods: Ovarian Cumulus Complexes (COCs) were cultured in the presence or absence of forskolin+IBMX during the first 2 hr of IVM (pre-IVM) with or without L-carnitine (LC) during IVM or IVC in six experimental groups as follows: I) pre-IVM (pre-IVM group), II) pre-IVM with L-carnitine supplementation during IVM (pre-IVM/LC group), III) L-carnitine supplementation during IVM (IVM/LC group), IV) L-carnitine supplementation during in vitro culture (IVC/LC group), V) pre-IVM+ IVC/LC group, and VI) no treatment during IVM and IVC (Control group). The cleavage and blastocyst rates, the blastocysts’ total cells number, and the expression of Nanog, Bax, Oct4, Cdx2, and Ifnt genes in resulting blastocysts were assessed. To assess differences among experimental groups, a one-way analysis of variance was initially employed, followed by post hoc Fisher LSD. The difference between groups was considered statistically significant when p<0.05.

Results: The cleavage and blastocyst rates in the Pre-IVM and Pre-IVM/LC groups was higher than control group and other groups (p≤0.05) except for IVC/LC and IVM/LC groups, respectively. The number of blastocyst’s Inner Cell Mass (ICM) in pre-IVM and Pre-IVM/LC groups as well as the ratio of ICM/TE were higher than control group (p<0.05). The expression of OCT4, CDX2, and IFNT increased in both the pre-IVM and pre-IVM/LC groups compared to the control group (p<0.05).

Conclusion: In conclusion, the application of SPOM-adapted IVM and L-carnitine during IVM of bovine oocyte improves the quantity and quality of the resulting embryos.