Anniek Bus1, Katarzyna Szymanska2,3, Isabel Pintelon4, Jo L M R Leroy5, Luc Leybaert3, Peter E J Bols5. 1. Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, Laboratory of Veterinary Physiology and Biochemistry, Gamete Research Centre, University of Antwerp, Universiteitsplein 1, U building, 2610, Wilrijk, Belgium. anniek.bus@uantwerp.be. 2. Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, 310 Cedar Street, New Haven, CT, 06510, USA. 3. Faculty of Medicine and Health Sciences, Department of Basic and Applied Medical Sciences (BAMS), Physiology group, Ghent University, C. Heymanslaan 10, B-9000, Ghent, Belgium. 4. Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, Laboratory of Cell Biology and Histology, University of Antwerp, Universiteitsplein 1, T building, 2610, Wilrijk, Belgium. 5. Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, Laboratory of Veterinary Physiology and Biochemistry, Gamete Research Centre, University of Antwerp, Universiteitsplein 1, U building, 2610, Wilrijk, Belgium.
Abstract
PURPOSE: Gap junctions and transzonal projections play a crucial role in intercellular communication between different follicular components and are necessary for follicle development. We aimed to demonstrate gap junction protein connexin 43 (Cx43) and transzonal projections (TZPs) in viable, category 1, isolated bovine pre-antral follicles (PAFs) during short-term culture and after vitrification and warming. METHODS: This study involved four experimental groups: fresh control, 2-day culture, 4-day culture, and vitrified secondary PAFs. Isolated PAFs were vitrified using a simple and efficient cryopreservation method by means of mini cell strainers. RESULTS: Cx43 and TZPs were detected in pre-antral follicles of all stages, as well as in every experimental group. The group fresh follicles showed a higher percentage of follicles that were positive for Cx43 (91.7%) than the follicles that were vitrified (77.4%). All follicles that were cultured for 2 days were Cx43-positive (100%). Follicles cultured for 4 days (65.8%) (P = 0.002) showed the lowest percentage of follicles that were Cx43-positive. The percentages of the presence or (partial) absence of the TZP network were shown to be very heterogeneous between follicles in different treatment groups. CONCLUSIONS: These results suggest the maintenance of communication between the oocyte and the somatic companion cells after vitrification and warming. The varying percentages of the expression of the TZP network within groups suggests that it will be of interest to investigate whether this is truly due to variability in TZP integrity and follicle quality or due to methodological limitations.
PURPOSE: Gap junctions and transzonal projections play a crucial role in intercellular communication between different follicular components and are necessary for follicle development. We aimed to demonstrate gap junction protein connexin 43 (Cx43) and transzonal projections (TZPs) in viable, category 1, isolated bovine pre-antral follicles (PAFs) during short-term culture and after vitrification and warming. METHODS: This study involved four experimental groups: fresh control, 2-day culture, 4-day culture, and vitrified secondary PAFs. Isolated PAFs were vitrified using a simple and efficient cryopreservation method by means of mini cell strainers. RESULTS: Cx43 and TZPs were detected in pre-antral follicles of all stages, as well as in every experimental group. The group fresh follicles showed a higher percentage of follicles that were positive for Cx43 (91.7%) than the follicles that were vitrified (77.4%). All follicles that were cultured for 2 days were Cx43-positive (100%). Follicles cultured for 4 days (65.8%) (P = 0.002) showed the lowest percentage of follicles that were Cx43-positive. The percentages of the presence or (partial) absence of the TZP network were shown to be very heterogeneous between follicles in different treatment groups. CONCLUSIONS: These results suggest the maintenance of communication between the oocyte and the somatic companion cells after vitrification and warming. The varying percentages of the expression of the TZP network within groups suggests that it will be of interest to investigate whether this is truly due to variability in TZP integrity and follicle quality or due to methodological limitations.
Authors: R F Silva; L F Lima; Anna C A Ferreira; A F B Silva; D R Alves; B G Alves; A C Oliveira; Selene M Morais; Ana Paula R Rodrigues; Regiane R Santos; J R Figueiredo Journal: Front Vet Sci Date: 2022-04-28