94 Effect of follicle-stimulating hormone source used during in vitro maturation of bovine cumulus-oocyte complexes on embryo production and morphological quality
L. Martins A , L. Martinhão A , I. Garcia B , D. Ribas B , J. Grázia C , O. Faria A , R. Figueiredo D and J. Viana DA University of Brasilia, Brasília, Distrito Federal, Brazil
B State University of Mato Grosso, Alta Floresta, Mato Grosso, Brazil
C FIVX Apoyar Biotech, Juiz de Fora, Minas Gerais, Brazil
D Embrapa Recursos Genéticos e Biotecnologia, Brasília, Distrito Federal, Brasil
Reproduction, Fertility and Development 35(2) 173-174 https://doi.org/10.1071/RDv35n2Ab94
Published: 5 December 2022
© 2023 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of the IETS
The recombinant human follicle-stimulating hormone (rhFSH) has been empirically used to replace porcine FSH (pFSH) during in vitro maturation (IVM) of cumulus-oocyte complexes (COC) recovered from cattle. However, few studies have directly compared the efficiency of these two sources of FSH in a commercial in vitro embryo production (IVEP) program. The aim of this study was to evaluate COC expansion and subsequent embryo production and quality when either rhFSH or pFSH are used during IVM. Grade I COC, with homogeneous cytoplasm and more than three layers of cumulus cells (n = 720, in two replicates) recovered from slaughterhouse ovaries were allocated into three groups, in which IVM was performed in TCM199 medium: (1) without FSH (−FSH, n = 240); (2) supplemented with 0.5 μg/mL pFSH (Folltropin-V, Vetoquinol, n = 240); or (3) supplemented with 0.1 UI/mL rhFSH (Gonal, Merck, n = 240), all in the same culture conditions (38.5°C, 5% CO2). The cumulus expansion was addressed at 22 h of IVM and subjectively scored as absent (no cumulus expansion), medium (little expansion), or good (considerable expansion). Semen from a single sire with known fertility was used for in vitro fertilisation. The presumptive zygotes were in vitro cultured under low oxygen atmosphere (5% CO2 and 5% O2, 38.5°C). On the seventh day of embryo culture, the blastocyst rate was evaluated, and a subset of the expanded blastocysts, Grade I (BX I, n = 21, 17, and 15 in groups −FSH, pFSH, and rhFSH, respectively), were submitted to differential staining using Hoechst 33342 (total cell number) and propidium iodide (trophoblast cells); inner cell mass (ICM) was determined by subtracting the trophoblast cell number from the total cells counted. The slides were evaluated under fluorescence microscopy (Axiophot 2, Zeiss). Data were analysed using the PROC NPAR or the Proc Glimmix of the SAS software (SAS Institute). COC expansion was similar (P > 0.05) between pFSH and rhFSH, and in both groups it was greater than in −FSH (P < 0.0001). The blastocyst rate, however, was greater in rhFSH compared with −FSH and pFSH (46.3% vs 34.6% and 38.0%, respectively; P = 0.0207). The BX from rhFSH presented more total cells than those from −FSH (153.3 ± 29.4 vs 132.2 ± 31.0, respectively; P = 0.0137) and more trophoblast cells than those from both −FSH and pFSH (110.3 ± 24.1 vs 80.0 ± 25.9 and 87.4 ± 22.4, respectively; P = 0.0030). There was no difference in the number of cells in the ICM among groups (52.2 ± 15.6, 47.3 ± 15.3, and 43.0 ± 15.5 for −FSH, pFSH, and rhFSH, respectively; P > 0.05), resulting in a lower ICM/total cell proportion in the rhFSH group compared with −FSH and pFSH (28.0 ± 9.5% vs 39.5 ± 9.5% and 35.1 ± 10.4%, respectively; P = 0.0237). In summary, pFSH can be replaced by rhFSH during IVM of cattle COC, improving IVEP. On the other hand, low cumulus expansion, as observed in the lack of FSH during IVM, does not impair blastocysts to be formed, even though at a lower rate.
This research was supported by CAPES, DPG UnB, and FAPDF.
