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Survival of Pacific oyster, Crassostrea gigas, oocytes in relation to intracellular ice formation
- Source :
- Cryobiology. 56(1)
- Publication Year :
- 2007
-
Abstract
- The effect of IIF in Pacific oyster oocytes was studied using cryo and transmission electron microscopy (TEM). The viability of oocytes at each step of a published cryopreservation protocol was assessed in an initial experiment. Two major viability losses were identified; one when oocytes were cooled to -35 degrees C and the other when oocytes were plunged in liquid nitrogen. Although the cryomicroscope showed no evidence of IIF in oocytes cooled with this protocol, TEM revealed that these oocytes contained ice crystals and were at two developmental stages when frozen, prophase and metaphase I. To reduce IIF, the effect of seven cooling programmes involving cooling to -35 or -60 degrees C at 0.1 or 0.3 degrees C min(-1) and holding for 0 or 30 min at -35 or -60 degrees C was evaluated on post-thaw fertilization rate of oocytes. Regardless of the cooling rate or holding time, the fertilization rate of oocytes cooled to -60 degrees C was significantly lower than that of oocytes cooled to -35 degrees C. The overall results indicated that observations of IIF obtained from cryomicroscopy are limited to detection of larger amounts of ice within the cells. Although the amount of cellular ice may have been reduced by one of the programmes, fertilization was reduced significantly; suggesting that there is no correlation between the presence of intracellular ice and post-thaw fertilization rate. Therefore, oyster oocytes may be more susceptible to the effect of high solute concentrations and cell shrinkage than intracellular ice under the studied conditions.
- Subjects :
- Oyster
Cell Survival
General Biochemistry, Genetics and Molecular Biology
Cryopreservation
Andrology
Human fertilization
Microscopy, Electron, Transmission
biology.animal
Animals
Crassostrea
Metaphase
biology
Ice crystals
Cryoelectron Microscopy
Ice
IIf
General Medicine
Liquid nitrogen
Pacific oyster
biology.organism_classification
Crystallography
Fertilization
Oocytes
Female
General Agricultural and Biological Sciences
Subjects
Details
- ISSN :
- 10902392
- Volume :
- 56
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- Cryobiology
- Accession number :
- edsair.doi.dedup.....0da93bc9f31e7e653537ea7eb8f37c66