SPERM ENERGY RESTRICTION AND RECOVERY (SER) TREATMENT IMPROVES SPERM FUNCTION IN THE BOVINE MODEL

ARROYO-SALVO, CAMILA; AGUILA, LUIS; OSYCKA SALUT, CLAUDIA ELENA; ECKENREITER, CHRISTINA; SHAW, RILEY; NAVARRETE, FELIPE; PEREZ MARTINEZ SILVINA; FISSORE, RAFAEL; VISCONTI, PE; GERVASI MARÍA GRACIA

Mar del Plata

Congreso; Reunión Conjunta de Biociencias 2023; 2023

The cattle industry relies on the successful application of assisted reproductive technologies to produce animals with higher economic value. In recent years, the use of in vitro produced embryos in the cattle industry has been on the rise on a global scale. Improvement of embryo production that increases the number and/or quality of embryos able to generate healthy offspring would have a considerable financial impact on the agricultural industry. We have recently shown that the use of sperm energy restriction and recovery (SER) treatment improved sperm function and increased fertilization and embryo development rates after in vitro fertilization (IVF) in mice. Here, we optimized the application of SER treatment in bull sperm and used it prior to intracytoplasmic sperm injection (ICSI) without exogenous chemical activation. Our results show an improvement on sperm motility after SER. In addition, when used prior to ICSI, the percentage of 2-cell embryos obtained with SER-treated sperm increased over 3-fold when compared to controls (50% SER, 16% control; P≤ 0.05). Moreover, 17% of the SER-derived embryos reached blastocyst stage while none of the control-derived embryos did (P≤ 0.05). We then investigated if these differences could be due to SER treatment facilitating the egg activation mediated by sperm. We found higher percentages of eggs that displayed more than 3 Ca2+ peaks after ICSI in the SER treatment in comparison to controls (40 % to 10%, respectively; P≤ 0.05). As sperm PLCz correlates with the occurrence of Ca2+ oscillations, we evaluated the localization of this protein in bull sperm. We observed no changes in PLCz localization in the sperm head after SER treatment in comparison to controls. Overall, our results indicate that SER treatment improves sperm function and facilitates egg activation and suggest that manipulation of sperm incubation conditions can increase the efficiency of in vitro embryo production.