Vitrification with DAP 213 and Cryotop of ex situ and in situ feline cumulus-oocyte complexes
Articolo
Data di Pubblicazione:
2012
Citazione:
Vitrification with DAP 213 and Cryotop of ex situ and in situ feline cumulus-oocyte complexes / E.A. Alves, A.C. Kozel, G.C. Luvoni. - In: REPRODUCTION IN DOMESTIC ANIMALS. - ISSN 0936-6768. - 47:6(2012 Mar 03), pp. 1003-1008. [10.1111/j.1439-0531.2012.02006.x]
Abstract:
This study was undertaken to compare cryotolerance, in terms
of viability and resumption of meiosis after warming and
culture (24 and 48 h), of ex situ (isolated) and in situ (enclosed
in the ovarian tissue) feline cumulus–oocyte complexes (COCs)
vitrified with DAP 213 (2 M DMSO, 1 M acetamide, 3 M
propylene glycol) in cryotubes or Cryotop method. Ovaries
were harvested from 49 pubertal queens. Of each pair of
ovaries, one was dissected to release COCs randomly divided
into three groups: fresh COCs (control), ex situ COCs vitrified
with DAP 213 and Cryotop. The cortex of the other ovary was
sectioned into small fragments (approximately 1.5 mm3) and
randomly assigned to be vitrified by DAP 213 or Cryotop.
After warming, ex situ and in situ (retrieved form vitrified
ovarian tissue) COCs were matured in vitro. Viability of
oocytes was highly preserved after warming and culture in all
treatments. Proportions of oocytes surrounded by complete
layers of viable cumulus cells were remarkably decreased
(p < 0.00001) in both vitrification procedures compared to
fresh oocytes. Resumption of meiosis occurred in all treatments.
After 24 h of culture, results were similar in ex situ and
in situ vitrified oocytes regardless of the vitrification protocol
used (range 29–40%), albeit lower (p < 0.05) than those of
fresh oocytes (65.8%). After 48 h of culture, ex situ oocytes
vitrified with Cryotop achieved the rates of meiosis resumption
similar to fresh oocytes (53.8% vs 67.5%; p > 0.05) and
ex situ and in situ oocytes vitrified with DAP 213 showed
similar rates of resumption of meiosis. These findings demonstrated
that DAP 213 and Cryotop preserve the viability of
ex situ and in situ oocytes, but cumulus cells are highly
susceptible to vitrification. However, the capability to resume
meiosis evidences that feline immature oocytes vitrified as
isolated or enclosed in the ovarian cortex have comparable
cryotolerance.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Cat ; ovarian tissue ; oocyte ; vitrification
Elenco autori:
E.A. Alves, A.C. Kozel, G.C. Luvoni
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