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Oliveira TA, Correia LFL, Schmaltz L, Locatelli Y, Freitas VJF, Souza-Fabjan JMG, Mermillod P. 26 Effect of different cryoprotectant concentrations on vitrification of invitro-matured bovine oocytes in paper containers. Reprod Fertil Dev 2021. [DOI: 10.1071/rdv33n2ab26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
A great challenge for successful oocyte vitrification is the development of a low-cytotoxic cryoprotectant solution in a safe device allowing ultra-rapid cooling. This study compared different concentrations of cryoprotectants for bovine IVM-oocyte vitrification in a safe paper container device on oocyte survival and cleavage rates. Abattoir ovaries were obtained and cumulus–oocyte complexes (COCs) were recovered by aspirating follicles of 3 to 6mm in diameter. A total of 470 COCs with homogeneous cytoplasm oocytes, surrounded by several layers of cumulus cells were selected, in 5 replicates. Groups of ∼50 COCs were matured in 500µL of semi-defined IVM medium for 22h at 38.8°C in a humidified atmosphere with 5% CO2. After IVM, COCs were allocated to 1 of 3 groups of 20 to 30 COCs, differing only in final concentration of cryoprotectants. A nonvitrified control group (CG) was also tested, totalling 4 groups. Before vitrification, each group was transferred to 500µL of TCM-199 HEPES with 20% fetal bovine serum (FBS) (Base medium, BM) for 5min at 34°C, and COCs were partially denuded by gentle pipetting. Vitrification followed a 3-step protocol at room temperature and groups of 4 to 5 COCs were transferred to BM solution drops containing (1) 5% ethylene glycol (EG) + 5% dimethyl sulfoxide (DMSO) for 30 s; (2) 10% EG + 10% DMSO + 0.25M sucrose for 30 s; and (3) vitrification solution (VS), according to each group: high (HG), 20% EG + 20% DMSO + 0.5M sucrose; medium (MG), 15% EG + 15% DMSO + 0.5M sucrose; or low (LG), 10% EG + 10% DMSO + 0.5M sucrose for 30s. Afterwards, COCs were loaded in <1µL of solution and placed in a homemade paper container device, and immediately plunged in liquid nitrogen. Warming was performed placing the paper container in 3mL of 1M sucrose in BM for 2min. After warming, a 3-step protocol was conducted and COCs were transferred to (1) 500µL of 0.5M sucrose in BM for 2 min; (2) 500µL of 0.25M sucrose for 2 min; (3) 500µL of BM for 2min. Then, COCs from each group were transferred to 250µL of semi-defined IVF medium. Motile sperm were recovered by Percoll washing from one bull and added to IVF medium (Day 0) at final concentration of 106 sperm mL−1 for 18h. At Day 1, all presumptive zygotes were cultured in 25µL of SOF medium with 5% FBS under mineral oil at 38.8°C with 5% CO2 and 5% O2. Normal data were subjected to ANOVA and post hoc Tukey test. Cleavage rate was recorded at Day 2 after IVF. Oocyte survival rate was similar (P>0.05) among vitrified groups (HG, 80%; MG, 86%; LG,87%). Cleavage rate differed (P<0.05) in all vitrified groups compared with control (CG, 82%; HG, 10%; MG, 16%; LG, 16%). Although no difference (P>0.05) was observed among vitrified groups, MG and LG showed a slightly increased oocyte survival and cleavage rates compared with HG. In conclusion, the use of either medium or low concentrations of cryoprotectants may be a less toxic alternative for vitrification of IVM bovine oocytes on paper device.
This research was funded by CAPES/COFECUB (#88881.142966/2017-01).
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Liu Y, Webber S, Bowgen K, Schmaltz L, Bradley K, Halvarsson P, Abdelgadir M, Griesser M. Environmental factors influence both abundance and genetic diversity in a widespread bird species. Ecol Evol 2013; 3:4683-95. [PMID: 24363897 PMCID: PMC3867904 DOI: 10.1002/ece3.856] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2013] [Revised: 09/16/2013] [Accepted: 09/17/2013] [Indexed: 12/05/2022] Open
Abstract
Genetic diversity is one of the key evolutionary variables that correlate with population size, being of critical importance for population viability and the persistence of species. Genetic diversity can also have important ecological consequences within populations, and in turn, ecological factors may drive patterns of genetic diversity. However, the relationship between the genetic diversity of a population and how this interacts with ecological processes has so far only been investigated in a few studies. Here, we investigate the link between ecological factors, local population size, and allelic diversity, using a field study of a common bird species, the house sparrow (Passer domesticus). We studied sparrows outside the breeding season in a confined small valley dominated by dispersed farms and small-scale agriculture in southern France. Population surveys at 36 locations revealed that sparrows were more abundant in locations with high food availability. We then captured and genotyped 891 house sparrows at 10 microsatellite loci from a subset of these locations (N = 12). Population genetic analyses revealed weak genetic structure, where each locality represented a distinct substructure within the study area. We found that food availability was the main factor among others tested to influence the genetic structure between locations. These results suggest that ecological factors can have strong impacts on both population size per se and intrapopulation genetic variation even at a small scale. On a more general level, our data indicate that a patchy environment and low dispersal rate can result in fine-scale patterns of genetic diversity. Given the importance of genetic diversity for population viability, combining ecological and genetic data can help to identify factors limiting population size and determine the conservation potential of populations.
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Affiliation(s)
- Yang Liu
- State Key Laboratory of Biocontrol and School of Life Sciences, Sun Yat-sen University Guangzhou, 510275, China ; Evolutionary Ecology Group and Computational and Molecular Population Genetics, Institute of Evolution and Ecology, University Bern Balzerstrasse 6, Bern, CH-3012, Switzerland
| | - Simone Webber
- Centre for Ornithology, University of Birmingham Edgbaston, Birmingham, BT15 2TT, UK
| | - Katharine Bowgen
- School of Applied Sciences, Bournemouth University, Talbot Campus Poole, Dorset, BH12 5BB, UK
| | - Lucie Schmaltz
- Animal Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen PO Box 11103, Groningen, 9700 CC, The Netherlands
| | | | - Peter Halvarsson
- Section of Animal Ecology, Department of Ecology and Evolution, Evolutionary Biology Centre, Uppsala University Uppsala, SE-75236, Sweden
| | - Mohanad Abdelgadir
- Section of Animal Ecology, Department of Ecology and Evolution, Evolutionary Biology Centre, Uppsala University Uppsala, SE-75236, Sweden ; Department of Biology, College of Sciences, University of Hail Hail, PO 2440, Saudi Arabia
| | - Michael Griesser
- Department of Ecology, Swedish University of Agricultural Sciences Uppsala, Sweden ; Anthropological Institute and Museum, University Zürich Zürich, 8057, Switzerland
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Schmaltz L, Albernaz M, Souza E. Endometrial hyperplasia with tibolone (LIVIAL®). Int J Gynaecol Obstet 2000. [DOI: 10.1016/s0020-7292(00)81474-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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