Franco M, Hansen PJ.
Effects of hyaluronic acid in culture and cytochalasin B
treatment before freezing on survival of cryopreserved bovine
embryos produced in vitro.
In Vitro Cell Dev Biol Anim. 2006 Jan-Feb;42(1-2):40-4.
Department of Animal Sciences, University
of Florida, Gainesville Florida 32611-0910, USA.
One limitation to the widespread use of in
vitro-produced embryos in cattle is their poor survival
following cryopreservation. Two approaches for enhancing
survival of in vitro-produced bovine embryos following
cryopreservation were evaluated: culture in the presence of
hyaluronic acid and alterations in the cytoskeleton through
cytochalasin B treatment. The experiment was a 2 x 2 factorial
design to test main effects of hyaluronic acid added to culture
at day 5 after insemination (+ or -) and cryopreservation
treatment (control or cytochalasin B). Embryos used for
cryopreservation were blastocysts and expanded blastocysts
harvested on day 7 after insemination. Cytochalasin B increased
the percent of embryos that re-expanded (P < 0.0001) and that
hatched following thawing (P < 0.05). The hatching percent was
29.6% for embryos treated with cytochalasin B versus 9.1% for
control embryos. There was no significant effect of hyaluronic
acid on survival although there was a tendency for embryos
cultured with hyaluronic acid to have higher percent hatching if
not treated with cytochalasin B (12.7% for hyaluronic acid
versus 4.5% for control; hyaluronic acid x cytochalasin B
interaction; P = 0.09). In conclusion, cytochalasin B treatment
before freezing improved cryosurvival of bovine embryos produced
in vitro. Such a treatment could be incorporated into methods
for cryopreservation of bovine embryos provided post-transfer
survival is adequate. In contrast, culture with hyaluronic acid
was of minimal benefit- the increased cryosurvival in the
absence of cytochalasin B was not sufficient to allow an
adequate number of embryos to survive.
PMID: 16618211 |
