Effects of slow freezing and vitrification on viability, ultrastructure and gene expression of canine embryos

Abstract

Gametes manipulation, embryo culture and cryopreservation using dogs as an experimental model may lead to techniques development that allows endangered canids genetic material preservation. This study aim to viable and compare the cryopreservation processes - slow freezing x canine embryo vitrification and evaluate this procedures effects on viability, ultraestruture and and gene expression of this structure. Embryos will be produced in vivo through program artificial inseminations, this bitches will be submitted to OSH and the embryos collected at blastocyst stage. Sixty canine embryos will be used divided into three groups, Control (CONT, n = 34), Vitrified (VITR, n = 34) and Frozen (CONG, n = 34). VITR group will be vitrified by "two step" technique and CONG group frozen in programmable freezing machine. After collection, heating and post-thawing all embryo remain for 24 hours in SOFaa in vintro culture. Reexpansion, viability by fluorescent probes, genic expression and eletronic microscopy evaluations will be performed in all groups.