Effect of cysteine, glutamate and glycine supplementation to in vitro fertilization medium during bovine early embryo development

ANCHORDOQUY, JUAN PATRICIO; LIZARRAGA, RAÚL MARTÍN; ANCHORDOQUY, JUAN MATEO; NIKOLOFF, NOELIA; ROSA, DIANA ESTHER; FABRA, MARIANA CAROLINA; PERAL-GARCÍA, PILAR; FURNUS, CECILIA CRISTINA

REPRODUCTIVE BIOLOGY

INST ANIMAL REPRODUCTION FOOD RESEARCH

Año: 2019

1642-431X

Glutathione (GSH) is an antioxidant synthesized from three constitutive amino acids (CAA): cysteine (Cys),glycine (Gly) and glutamate (Glu). Glutathione plays an important role in oocyte maturation, fertilization andearly embryo development. This study aimed to investigate the effect of Cys (0.6 mM), Gly (0.6 mM) and Glu(0.9 mM) supplementation during in vitro fertilization (IVF) of cattle oocytes. In a Pilot Experiment, de novosynthesis of GSH in bovine zygote was evaluated using a modified TALP medium prepared without MEM-essentialand MEM-non-essential amino acids (mTALP): mTALP+CAA (constitutive amino acids);mTALP+CAA+5 mMBSO (buthionine sulfoximide); mTALP+Cys+Gly; mTALP+Cys+Glu andmTALP+Gly+Glu. This evidence led us to investigate the impact of CAA supplementation to TALP medium(with essential and non-essential amino acids) on zygote viability, lipid peroxidation, total intracellular GSHcontent (include reduced and oxidized form; GSH-GSSG), pronuclear formation in zygotes and subsequentembryo development. IVF media contained a) TALP; b) TALP+Cys+Gly+Glu (TALP+CAA); c)TALP+Cys+Gly; d) TALP+Cys+Glu; e) TALP+Gly+Glu, were used. Total GSH-GSSG concentration wasincreased in TALP, TALP+CAA, and TALP+Cys+Gly. The viability of zygote was similar among treatments.Lipid peroxidation was increased in zygote fertilized with TALP+Cys+Gly; TALP+Cys+Glu;TALP+Gly+Glu and TALP+CAA. The percentage of penetrated oocytes decreased in TALP+CAA andTALP+Cys+Gly. The cleavage rate was lower in TALP+CAA and TALP+Gly+Glu. The percentage ofembryos developing to the blastocyst stage was lower in TALP+Cys+Glu and TALP+CAA. In conclusion, wehave demonstrated the synthesis of GSH during IVF. However, Cys, Gly and Glu supplementation to TALPmedium had negative effects on embryonic development.