This study was conducted to investigate the effect of various addition and exclusion time of glucose (Control: no addition, A: 24～72 h, B: 24～48 h, C: 48～72 h, D: 0～72 h, E: 0～48 h, F: 0～24 h and 48～72 h, G: 0～24 h) on embryonic developmental capacity of 2-cell embryos in mice. Developed blastocysts were assessed for mean cell number by differential staining. The zona-intact blastocyst (ZiB) rates were higher (p<0.05) in group B than control. However, the zona-escape blastocyst (ZeB) rates were not significantly different in all groups. At 72 h, total blastocyst (ZiB + ZeB) formation rates were not significantly different in all groups. The mean cell number was not significantly different among all groups. The inner cell mass (ICM) cell number was higher (p<0.05) in group F than control, group A, B and G. The trophectoderm (TE) cell number was higher (p<0.05) in control than group A and D. The %ICM was higher (p<0.05) in group C, D and F than control. The ICM : TE ratio was not significantly different in all groups. Between control and glucose group, no significant difference was observed in the total blastocysts (ZiB + ZeB) formation rates. Also, no significant difference was observed in the mean cell number, ICM cell number and ICM : TE ratio. However the TE cell number was higher (p<0.05) in control than glucose group and %ICM was higher (p<0.05) in glucose group than control. In conclusion, glucose added in culture medium was not inhibitory on blastocyst formation but glucose added for 48 ～72 h in culture medium increases %ICM of blastocysts in mice.

Molecular genetic markers were genotyped used to detect chromosomal regions which contain economically important traits such as growth traits in pigs. Three generation resource population was constructed from a cross between the Korean native boars and Landrace sows. A total of 193 F2 animals from intercross of F1 were produced. Phenotypic data on 7 traits, birth weight, body weight at 3, 5, 12, 30 weeks of age, live empty weight were collected for F2 animals. Animals including grandparents (F0), parents (F1), offspring (F2) were genotyped for 194 microsatellite markers covering from chromosome 1 to 18. Quantitative trait locus analyses were performed using interval mapping by regression under line-cross model. To characterize presence of imprinting, genetic full model in which dominance, additive and imprinting effect were included was fitted in this analysis. Significance thresholds were determined by permutation test. Using imprinting full model, four QTL with expression of imprinted effect were detected at 5% chromosome-wide significance level for growth traits on chromosome 1, 5, 7, 13, 14, and 16.

This study was carried out to evaluate the effects of glucose and sodium phosphate on in vitro development of porcine oocytes matured and fertilized in vitro. When the culture medium was supplemented with various concentrations of glucose, the higher proportions (23 and 26%) of oocytes developed to morular or blastocyst stages were at the concentrations of 2.78 and 5.56 mM than 0 (9%; P<0.05) and 11.12 mM (18%). In experiment to evaluate effect of sodium phosphate during in vitro development of porcine oocytes, a significantly (P<0.05) higher proportions of embryos developed to morular or blastocyst stages was obtained with sodium phosphateof 0.28 (25%) and 0.53 (27％) mM than 0 (15%), 1.05 (19%) and 2.10 (10%) mM. On the other hand, when oocytes were cultured in medium with (0.53 mM) sodium phosphate, the proportions of developed embryos were significantly (P<0.05) higher in medium without (29%) that than with (14%) 5.56 mM glucose. However, a higher proportion of embryos developed to morular or blastocyst stages were obtained in medium with (23%) that than without (8%) glucose (P<0.05). The minimum essential medium (MEM) added to the culture medium were higher regardless of presence of sodium phosphate and glucose on the development of embryos. Although sodium phosphate and glucose could support morular and blastocyst development to a limited extend (10∼24%), significantly higher proportion (36%) at morular or blastocyst stages was obtained by MEM adding in the medium with sodium phosphate and glucose. These results suggest that the early development of in vitro fertilized porcine oocytes can be maintained efficiently by glucose and sodium phosphate when they were cultured in medium with MEM.

The purpose of this study was to investigate the development of bovine nuclear transfer (NT) embryos cultured in serum-free conditions. Bovine NT embryos cultured in various culture conditions were compared blastocyst development, total cell number and apoptosis using TUNEL assay. In experiment 1, blastocyst rates of NT embryos were significantly higher (P<0.01) in FBS (22.0％) and BSA (26.6％) groups than in PVA (6.3％) group. Total cell number was significantly higher in FBS (78.4±19.4) and BSA (90.9±29.1) groups than in PVA group (46.0±0.0). Apoptotic cell number was significantly fewer in FBS (3.1±1.4) and BSA (1.7±1.4) groups than in PVA group (7.0±20.0) However, all of results were not different between the FBS and BSA group. In experiment 2, blastocyst rates of NT embryos were significantly higher (P<0.05) in fatty acid free-BSA (FAF-BSA) group (26.8％) than in fraction V-BSA group (11.2％). Total cell number were somewhat higher in FAF-BSA group (89.8±30.7) than in fraction V-BSA group (88.1±19.3). Apoptotic cell number were somewhat fewer in FAF-BSA (1.7±1.5) group than in fraction V-BSA group (4.2±2.9). These findings suggest that serum free condition were effective for the in vitro development of bovine NT embryos. Therefore, we concluded that fatty acid free-BSA has beneficial effect in development bovine NT embryos and can be use as a serum substitute.