Pre-fertilization approach using α-l-fucosidase modulates zona pellucida hardening during bovine in vitro embryo production

• Published in: Veterinary research communications Vol. 48; no. 2; pp. 1135 - 1147
• Main Authors: Manssur, Thainá Sallum Bacco, Sebastião, Talita Raquel Cavichioli, Franchi, Fernanda Fagali, dos Santos, Priscila Helena, Razza, Eduardo Montanari, Nunes, Sarah Gomes, Castilho, Anthony César de Souza, Fontes, Patricia Kubo
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.04.2024; Springer Nature B.V
• Subjects: Biomedical and Life Sciences; Blastocysts; In vitro fertilization; Life Sciences; Veterinary Medicine/Veterinary Science; Zona pellucida; Zoology; Gene Expression; FUCA; Polyspermy; Cattle; Blastocyst
• ISSN: 0165-7380; 1573-7446
• DOI: 10.1007/s11259-023-10291-y

The polyspermy occurrence is considerably lower under in vivo compared to in vitro embryo culture conditions, suggesting that the presence of some factors in the maternal environment is responsible for this. The α-L-fucosidase (FUCA) is a natural glycosidase present in the oviductal fluid, therefore, this study aimed at investigating the effect of adding FUCA to the hardening of the zona pellucida (ZP), polyspermy control, and embryonic yield and quality of bovine blastocysts produced in vitro. In the first experiment, the effect of FUCA (0.125 U/mL) was evaluated during the entire in vitro fertilization (IVF). However, it was demonstrated to be embryotoxic by completely inhibiting the blastocyst formation. In the second experiment, the FUCA (0.125 U/mL) was tested as short-term incubation before IVF (pre-fertilization step) for 30 min or 2 h, which demonstrated that FUCA treatment for 30 min resulted in ZP hardening. In the third experiment, a pre-fertilization FUCA treatment (1 h) at different concentrations (0, 0.0625, and 0.125 U/mL) showed that FUCA (0.0625 U/mL) improved pre-fertilization ZP hardening and tended to increase monospermic fertilization rates but did not improve embryo yield and quality. Together, it has been demonstrated that FUCA can induce oocyte pre-fertilization ZP hardening and might improve monospermic fertilization performance, and this effect is dependent on both variables (protein concentration and incubation time).