Ultrastructural Changes in Bovine Oocytes Cryopreserved by Vitrification

Fuku, E.; Xia, L.; Downey, B.R.

doi:10.1006/cryo.1995.1013

Cited by 162 publications

(98 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Therefore, immature oocytes seem to be more vulnerable to cryodamage than matured oocytes [36], which contributes to explain our results. As previously demonstrated in mouse [29], exposure to high CP concentrations may trigger premature release of CG, altering their distribution after warming and IVM [49] and resulting in hardening of the ZP with decreased fertilization outcomes [50,51].…”

Section: Discussionmentioning

confidence: 81%

Bovine oocyte vitrification before or after meiotic arrest: effects on ultrastructure and developmental ability

et al. 2005

View full text Add to dashboard Cite

The nuclear stage at which oocytes are cryopreserved influences further development ability and cryopreservation affects ultrastructure of both cumulus cells and the oocyte. In this work, we analyze the effects of vitrification at different nuclear and cytoplasmic maturation stages on the oocyte ultrastructure and developmental ability. Culture in TCM199 + PVA with roscovitine 25 M during 24 h led to meiotic arrest (MA) in cumulus-oocyte complexes (COCs), while permissive in vitro maturation (IVM) was performed in TCM199, 10% FCS, FSH-LH and 17b-estradiol for 24 h. Oocytes were vitrified using the open pulled straw method (OPS) with minor modifications. Fresh and vitrified/warmed COCs were fixed as immature, after IVM, after meiotic arrest (MA) and after MA + IVM.Vitrification combined with MA followed by IVM produced the highest rates of degeneration, regardless of the vitrification time. As a consequence, lower proportions of embryos cleaved in these groups, although differences were eliminated at the five-eight cell stage. Development rates up to day 8 were similar in all experimental groups, being significantly lower than those in fresh controls. Only oocytes vitrified after IVM were able to give blastociysts. The morphological alterations observed can be responsible for compromised development. More research is needed to explain the low survival rates of the bovine oocyte after vitrification and warming. #

show abstract

Section: Discussionmentioning

confidence: 81%

Bovine oocyte vitrification before or after meiotic arrest: effects on ultrastructure and developmental ability

et al. 2005

View full text Add to dashboard Cite

show abstract

“…Hay et al [45] and Assey et al [46] demonstrated that cytoplasmic vacuoles are also a characteristic sign of degeneration in both granulosa and cumulus cells during degeneration in vivo. According to Fuku et al [47], in bovine cryopreserved oocytes, these vacuoles may represent altered mitochondria. The ultrastructural analysis also demonstrated that the ultrastructural morphology of cryopreserved follicles in 3 M EG was better preserved than that of follicles cryopreserved in 1.5 M EG and GLY at both concentrations.…”

Section: Discussionmentioning

confidence: 99%

Cryopreservation of caprine ovarian tissue using glycerol and ethylene glycol

et al. 2004

View full text Add to dashboard Cite

Cryopreservation of ovarian tissue may be a potential alternative for the conservation of genetically superior animals, including high milk-and meat-producing goat breeds. However, until now, no information was available concerning the cryopreservation of preantral follicles (PF) enclosed in caprine ovarian tissue. The objective of the present study was to evaluate the structural and ultrastructural characteristics of caprine PF after exposure to and cryopreservation of ovarian tissue in 1.5 and 3 M glycerol (GLY) and ethylene glycol (EG). At the slaughterhouse, each ovarian pair from five adult mixed breed goats was divided into nine fragments and randomly distributed into treatment groups. One fragment was immediately fixed for histological examination and ultrastructural analysis, after slaughter (control). Four of the ovarian fragments were equilibrated at 20 °C for 20 min in 1.8 ml of MEM containing 1.5 or 3 M GLY or EG for a toxicity test and the final four fragments were slowly frozen using these cryoprotectants at the concentrations above. After toxicity testing and freezing/thawing, the ovarian fragments were fixed for histological examination. Histological analysis showed that after toxicity testing and cryopreservation of the ovarian tissue in GLY or EG at both concentrations, the percentage of normal PF was significantly lower than controls. Ultrastructural analysis of PF frozen in 1.5 and 3 M GLY, as well as 3 M EG demonstrated that these follicles remained morphologically normal. In conclusion, we demonstrated cryopreservation of caprine PF in ovarian tissue.

show abstract

“…Furthermore, the follicles showed an extreme ooplasm vacuolization, which is a characteristic sign of degeneration and may represent endoplasmic reticulum swelling (Tassel andKennedy, 1980 andSilva et al, 2000), altered mitochondrial structure (Fuku et al, 1995), or cellular necrosis (de Bruin et al, 2002). Therefore, despite being a time-consuming and expensive technique, TEM is an important tool for detecting early morphological changes after follicular culturing in vitro.…”

Section: Discussionmentioning

confidence: 99%

In vitro development of primordial follicles after long-term culture of goat ovarian tissue

Matos

Bruno

Rocha

et al. 2011

Research in Veterinary Science

View full text Add to dashboard Cite

This study aims to investigate the effects of follicle stimulating hormone (FSH) and fibroblast growth factor-2 (FGF-2) on the survival and growth of caprine preantral follicles. Ovarian tissues were cultured for 1, 7, 14, 21 or 28 days in medium supplemented with FSH (FSH-2d or FSH-7d, i.e., with replacement of the culture medium every 2 or 7 days, respectively) or FSH + FGF-2 (replacement of the medium every 2 days). Non-cultured (control) and cultured ovarian fragments were processed for histological and ultrastructural analysis. After 28 days of culture, the media supplemented with FSH-2d was the most effective in maintaining the percentage of normal follicles and in promoting follicular growth. Furthermore, both treatments with FSH increased the percentage of the primary follicles. However, ultrastructural studies did not confirm follicular integrity from 14 days of culture onward. In conclusion, culturing tissue for up to 7 days in medium containing FSH alone or combined with FGF-2 maintains caprine preantral follicle integrity and promotes their growth in vitro.

show abstract

Ultrastructural Changes in Bovine Oocytes Cryopreserved by Vitrification

Cited by 162 publications

References 0 publications

Bovine oocyte vitrification before or after meiotic arrest: effects on ultrastructure and developmental ability

Bovine oocyte vitrification before or after meiotic arrest: effects on ultrastructure and developmental ability

Cryopreservation of caprine ovarian tissue using glycerol and ethylene glycol

In vitro development of primordial follicles after long-term culture of goat ovarian tissue

Contact Info

Product

Resources

About