Effect of different cryoprotectants on the structural preservation of follicles in frozen zebu bovine (Bos indicus) ovarian tissue

Abstract

Effect of different cryoprotectants on the structural preservation of follicles in frozen zebu bovine (Bos indicus) ovarian tissueCarolina M Lucci Mirella A Kacinskis Luiz Henrique R Lopes Rodolfo Rumpf Sônia N Báoa AbstractCryopreservation of ovarian tissue is a new and promising technique for germ-line storage. The objective of this study was to evaluate the effect of four cryoprotectants (at two concentrations each) on the preservation of zebu bovine preantral follicles after ovarian cryostorage. Strips of ovarian cortex were cryopreserved using glycerol (GLY; 10 or 20%), ethylene glycol (EG), propanediol (PROH) or dimethylsulphoxide (DMSO; 1.5 or 3 M). In addition, a toxicity test was performed for each cryoprotectant by exposing the ovarian tissue to them without freezing. Tissues were analyzed by histology and transmission electron microscopy. Ovarian tissue frozen in either concentration of DMSO or PROH or in 10% GLY retained a higher percentage of morphologically normal follicles (73-88%) than tissue frozen in 20% GLY or in either concentration of EG (16-52%). In the toxicity test, exposure of tissues to DMSO, PROH or GLY resulted in higher percentages of normal follicles (80-97%) than exposure to EG (49%). Electron microscopy revealed damage to the ultrastructure of follicles frozen in 10% GLY, while follicles cryopreserved in DMSO and PROH at either concentration exhibited normal ultrastructure. In conclusion, DMSO and PROH were the most effective cryoprotectants for zebu ovarian tissue, preserving the structural integrity of somatic and reproductive cells within the ovary.

Ultrastructural features of agouti (Dasyprocta aguti) preantral follicles cryopreserved using dimethyl sulfoxide, ethylene glycol and propanediol

“…Unlike results previously reported in our studies in pigs [23], cattle [30], and sheep [19], DMSO was able to maintain the ultrastructure of preantral follicles enclosed in ovarian tissue after cryopreservation. In follicles included in ovarian tissue that were cryopreserved in the presence of EG, greater damage was observed in this study, manifested as reduced electron density and fewer organelles in the ooplasm.…”

Review on Ovarian Cryopreservation in Large Animals and Non-Human Primates

“…While the study by Celestino and colleagues (Celestino et al, 2008) showed increased toxicity with rising concentration of DMSO, the other study (Lucci et al, 2004) showed slightly higher proportion of normal follicles in the 3 M DMSO group when assessed by conventional histology. However, ultrastructural analysis by transmission electron microscopy (TEM) revealed some irregularities in the cytoplasm of granulosa cells when 3 M DMSO was applied (Lucci et al, 2004).…”

“…The toxic effect of various concentrations and types of CPAs that are frequently used for slow freezing was compared using bovine ovarian cortical strips (Lucci et al, 2004;Celestino et al, 2008). Among other CPAs, DMSO at 1.5 M and 3 M were evaluated in both studies.…”

Influência da temperatura de transporte de ovários na maturação in vitro de oócitos caninos coletados em diferentes estágios do ciclo estral

“…O transporte de ovários à 4°C possibilitou a preservação dos oócitos, especialmente dos obtidos da fase de diestro, devido aos altos índices de M-II encontrados nesta fase do ciclo estral. Lucci et al (2004) observaram que os ovários de vacas zebuínas puderam ser armazenados com sucesso na temperatura de 4°C por até 18 horas, sem ocasionar danos morfológicos aos folículos pré-antrais. Entretanto, na temperatura de 20°C, esses ovários só puderam ser estocados por seis horas.…”