DNA methylation at CpG sites, which is a epigenetic modification, is associated with gene expression without change of DNA sequences. During early mouse embryogenesis, dynamic changes of DNA methylation occur. In this study, DNA methylation patterns of porcine embryos produced in vivo and in vitro were examined at various developmental stages by the immunocytochemical staining method. Interestingly, active demethylation was not observed on the paternal pronucleus of porcine zygotes. However, differences were detected in the passive demethylation process between in vivo and in vitro embryos. There was no change in the DNA methylation state until the blastocyst stage of in vivo embryos, whereas partial demethylation was observed in several blastomeres from a 4 cell stage to a morula stage of in vitro embryos. The whole genome of inner cell mass (ICM) and trophectoderm (TE) cells in porcine blastocysts were evenly methylated without de novo methylation. Our findings demonstrate that genome-wide demethylation does not occur in pig embryos during preimplantation development unlike murine and bovine embryos. It indicates that the machinery regulating epigenetic reprogramming may be different between species.

본 연구는 야생콩과 재배콩의 교잡 후대 집단에서 25계통을 선발하여 사료 수량 및 품질을 평가하여 사료용 콩 품종육성 가능성을 검토하였으며, 그 결과를 요약하면 다음과 같다. 먼저, 야생콩과 재배콩 교잡종의 조사료 수확시기별 수량 및 품질 검정에서 교잡종을 대조품종인 재배콩과 비교하여 보았을 때 사료의 수량이나 품질을 고려하면 협비대기인 R6에 가장 우수한 것으로 평가가 되었다.야생콩과 재배콩의 교잡후대 계통에 대한 사료 수량 및 품질평가에서 대조품종과 비슷하거나 유의적인 차이가 없는 수량이 높은 계통을 선발할 수 있었으며, 가식부위 생체중은 대조품종인 재배콩 보다 교잡종이 상대적으로 높은 것으로 평가가 되었다. 교잡종에 대한 사료품질을 평가한 결과 AFGC의 두과 건초 품질 등급기준에 따라 나누었을 때, 특등급의 조건인 조단백질 함량 19% 이상, NDF 함량 40% 미만, ADF 함량 31% 미만, DDM 65% 이상, DMI 3.0% 이상, RFV 151 이상을 모두 충족시키는 계통을 선발할 수 있었고, 이들중 몇몇 계통은 수량도 우수한 것으로 평가가 되었다. 따라서, 재배콩과 야생콩의 교잡을 통해 사료 수량 및 품질이 우수한 사료용 콩을 개발할 수 있을 것으로 판단된다.

Soluble-NSF attachment protein receptor (SNARE) proteins play a role in vesicle fusion, exocytosis, and intracellular trafficking in neuronal cells as well as in fertilization and embryogenesis. We investigated the expression patterns of two SNARE proteins, SNAP-25 and synaptotagmin VII (SytVII), and their regulation by pregnant mare serum gonadotropin (PMSG) during mouse ovarian follicular development. Ovaries were obtained at 0, 12, 24, 36, and 48 h post-PMSG injection of immature mice. SNAP-25 and SytVII mRNA expression levels increased gradually in a time-dependant manner. However, protein levels revealed different patterns of expression, suggesting different translational regulation following PMSG stimulation. SNAP-25 and SytVII expression was closely associated with thickening of the granulosa cell (GC) layer and follicle morphological changes from a flattened to a cuboidal shape. To explore follicle stimulating hormone receptor (FSHR)-mediated regulation of their expression, GCs from preantral follicles were cultured to examine the effects of FSHR siRNA knockdown. FSHR siRNA abolished upregulation of the SNAREs in both PMSG and FSH-stimulated GCs. This abolished gene expression was rescued by adding dibutyryl cyclic AMP to the cultures. These results suggest that SNAP-25 and SytVII expression is regulated via the FSHR-cAMP pathway during follicular development.

"Early Valley", is an early maturing potato cultivar with high yield potential. "Early Valley" is a clonal selection resulting from the cross between 'Suncrisp' and 'A87109-10'. It has medium plant height and light green foliage. "Early Valley" has medium flowering habit and white flowers. Tubers are smooth, yellow skin, light yellow flesh, round tuber shape, medium eye depth, and medium dormancy and good keeping quality. It has stable yield under wide range of climatic conditions. "Early Valley" is resistance to late blight, but moderately susceptible to common scab and hollow heart. This cultivar is also resistant to potato rotting at harvesting during the raining season. "Early Valley" has high level of antioxidant activity (about three times higher) and vitamin C (higher by 40%) than the 'Superior'. This cultivar has high level of tuber uniformity and capable of yielding 36.56 t/ha which is 17.07% higher than the control potato cultivar 'Superior' under optimum agronomical practices.

Bovine embryos produced by in vitro maturation, feretilization and development was examined for presevation and transfer. The fertilization medium used BO medium with 5 mM/ caffeine and 10/ heparin and adjusted to a pH of 7.2 to 7.4. The final concentration of spermatozoa was adjusted to 1 cells/ motile sperm during fertilization in vitro. At 8~10 hrs after insemination, the oocytes were transferred into CR1aa medium and cultured for 7 days. Embryos were preserved by vitrification method for transfer. When the embryos of early, blastocyst and expanded blastocyst stages were frozen-thawed, the proportions of embryos with normal morphology 83.6, 88.1 and 85.2%. (중략)