Until recently, there have been many researches about the freezing methods and several methods of cryopreservation. Hypothermic preservation has been used to complement the embryo freezing technology. There is a study to show the successful results for long-term hypothermic preservation. For that reason, FBS and BSA are commonly added to the culture medium to support embryo development. We investigated the effectiveness of hypothermic preservation method at 4℃ according to embryonic developmental stages for Hanwoo embryos and evaluated the effect of FBS and BSA on Hanwoo embryos as a supplemental reagent in hypothermic preservation medium after recovering preserved embryos from hypothermic preservation. The present study reported that survival and hatching rates of embryos at morula stage following storage at 4℃ is Day 7 group was significantly higher (p < 0.05) compared than those of other groups (p < 0.05). As a result, the survival and hatching rates of embryos at the blastocyst stage following storage at 4℃ result is showed that significantly higher (p < 0.05) survival rates than those of other groups an Day 6. The result showed that hatching rate at Day 6 and 7 were significantly lower (p < 0.05) compared with other groups. The result regarding the survival and hatching rates of bovine embryos following storage at 4℃ for 72 h in various concentrations of BSA are shown The results showed that survival rate of 1% BSA group was not significantly different (p < 0.05) compare with control (FBS) group. Also, the results showed that hatching rate of control (FBS) and 1% BSA were significantly different (p < 0.05) compared with other groups. In conclusion, our result demonstrated that the hypothermic preservation did not effect on the survival and hatching rates of embryos after recovering. In addition, the supplementation of BSA in preservation medium showed no difference in the embryo developmental competence after hypothermic preservation compared to FBS treatment. With that, BSA can be an alternative reagent for the hypothermic preservation medium as an energy source and pH buffer.

Cryopreservation of bovine embryos is used to efficiently implant surrogate mothers. It has been widely accepted that high lipid content in the oocyte interrupts its survival during freeze-thaw cycles. Serum component in the culture medium is thought to increase the embryo`s lipid contents. Conversely, L-carnitine stimulates lipid metabolism by transporting long chain fatty acids into the mitochondria. Objective of this study was to analyze the effect of L-carnitine supplementation in IVM medium and defined IVC medium on the development, lipid contents and the cryosurvival of bovine IVF embryos. 0.0, 1.5, 3.0 and 6.0 mM L-carnitine was supplemented in IVM medium, respectively (IVM-LC 0.0, LC 1.5, LC 3.0 and LC 6.0). Development rate from the 2cell to the morula stages was higher in IVM-LC 3.0 groups than those of IVM-LC 6.0 (p<0.05). But there were no significant differences among the other groups in the blastocyst rates and lipid content results. When 0.0, 1.5, 3.0 and 6.0 mM L-carnitine were supplemented in IVC medium (IVC-LC 0.0, LC 1.5, LC 3.0 and LC 6.0), development competence was not significantly different between those embryos. Lipid contents of embryos treated L-carnitine (IVC-LC 1.5, 3.0 and 6.0) were significantly lower than embryos of non-treated group. L-carnitine was supplemented 0.0, 1.5, 3.0, 6.0 mM during IVM and 3.0 mM during IVC (LC 0.0 - 3.0, LC 1.5 – 3.0, LC 3.0 – 3.0, LC 6.0 – 3.0) and cryosurvival of blastocysts confirmed after freezing-thawing. There were no significant differences on development, but LC 3.0 – 3.0 was significantly lower lipid contents than other groups. And LC 3.0 – 3.0 had better survival rates and hatched rates of blastocysts than LC 0.0 – 0.0. In conclusion, supplementation of L-carnitine in defined IVC medium decreases lipid contents. And L-carnitine supplementation improves cryosurvival and developmental ability of bovine IVF embryos.

The early-onset familial Alzheimer's disease (EOFAD/ FAD), the less common type of Alzheimer's disease (AD) currently affects a vast number of individuals worldwide. This type is being inherited as an autosomal dominant fashion. Missense mutations on Amyloid precursor protein (APP) and Presenilins 1 and 2 (PSEN1 & PSEN2) are known as major genetic factors in FAD. Conversely, missense mutations on microtubule-associated protein tau (MAPT) are also thought to involve. Up to date, several triple-transgenic animal models with muted forms of the human APP, PSENs and MAPT have been reported. Compared to other animals, canines are more emotional and their disease signs can be easily diagnosed. This attempt was to develop a triple transgenic canine model for the AD. We have obtained the coding sequences of APP, PSEN1 and MAPT from Dana-Farber/Harvard Cancer Center DNA resource core at HMS and incorporated several common AD mutations. The transgenic construct is composed of hNSE (ENO2) promoter-driven three AD genes fused together with modified 2A sequences. It was transfected into the canine fetal fibroblasts which were then used to perform somatic cell nuclear transfer (SCNT). The viable transgenic embryos were obtained after in vitro culture and the GFP was detected. In this study, we have successfully produced viable triple transgenic canine cloned embryos using SCNT technique. These transgenic canine embryos will be further developed into canines with FAD. The transgenic canines will be a good candidate in the AD research field.