Sexing from bovine embryos which were fertilized in vitro implicate a possibility of the sex-controlled cattle production. This study was carried out to investigate the possibility of determining of embryo sex by fluorescence in situ hybridization (FISH) technique. FISH was achieved in in vitro fertilized bovine embryos using a bovine Y-specific DNA probe which constructed from the btDYZ-1 sequences. To evaluate Y-chromosome specificity of the FISH probe, metaphase spreads of whole embryos and lymphocytes were prepared and tested. A male-specific signal was detected on 100% of Y chromosome bearing metaphase specimens. Using the FISH technique with a bovine Y-specific probe, 232 whole embryos of 8 cell- to blastocyst-stage were analyzed. Observing the presence of the Y-probe signal on blastomeres, 102 embryos were predicted as male, and 130 embryos as female. The determining rate of embryo sex by FISH technique was about 93% regardless of embryonic stages. In conclusion, the FISH using a bovine Y-specific DNA probe is an accurate, reliable and quick method for determining the sex of bovine embryos.

Polyeyclic aromatic hydrocarbons (PAHs) were quantitatively determined in bivalves from Gwangyang Bay. Twenty-four kinds of target PAHs were detected in the entire samples. Total PAHs concentrations ranged 86.1∼1,210 ng g-1/ dry weight with a average

인체 트롬보포이에틴(hTPO)은 megakaryopoiesis 과정에 주요한 역할을 하는 사이토카인이다. 따라서 이러한 트롬보포이에틴을 유선조직에서 직접적으로 발현시키기 위하여 소 베타 카제인 프로모터, 인체 트롬보포이에틴 cDNA 및 네오유전자로 구성된 발현벡터를 구축하였다. 소 귀조직 세포로부터 유도된 섬유아세포에 lipoffctamine을 이용하여 발현벡터(pBT-L n대)의 삽입을 유도하였다. G4l8 저항성을 지닌 세포의 콜로니 형성을 유도하기 위하여 2주 이상 배양을 실시하였다. 형질전환 콜로니는 PCR에 의해 동정하였으며, 이들 콜로니를 핵치환 전까지 계속적으로 증식을 유도하였다. 형질전환 세포에 의해 재구성된 난자는 전기적인 융합과 calcium ionophore와 6-DMAP를 이용한 활성화를 실시하였으며, 체외에서 7일간 배양을 실시하였다. 총 35개의 콜로니를 PCR에 의해 분석한 결과, 이 중 29(82.9%)개가 형질전환된 콜로니였다. 형질전환된 세포로 재구성된 난자의 난할율 및 배반포로의 발달율은 65.1%와 23.8%로 나타났다. 형질전환된 세포로 재구성된 난자로부터 발달한 29개의 배반포 중 27개가 형질전환으로 확인되었다. 따라서 이러한 결과들은 형질전환 소 수정란을 형질전환된 세포를 이용한 체세포 복제 기법을 통해 효과적으로 생산할 수 있다는 것을 제시하고있다.

The purpose of this study was to investigate the effect of kind and combination of sugars on the viability and acrosome damage of post-thaw spermatozoa in canine. The extender used was Tris-citric acid extender (Tris-buffer) supplemented with 20% Egg-yolk, 8% glycerol, 1% Equex STM paste, and 70 mM sugars such as monosaccharide (fructose and xylose) and disaccharide(trehalose). To evaluate of sugar combination, the sugars supplemented in Tris-buffer were combined such as single (fructose, xylose, trehalose), two combinations (Fruc+Tre, Fruc+xyl, Tre+xyl) and three combinations (Fruc+Tre+Xyl). The concentration of sperm collected were adjusted of 50106/ per straw for freezing. The frozen spermatozoa were thawed at 37 for 1 min and then analysis for CASA program in Livestock Improvement Main Center, NACF. The motility of post-thaw spermatozoa in Fruc+Tre was higher than those in fructose, trehalose, xylose, Fru+xyl, Tre+xyl and Fru+Tre+Xyl (79％ vs. 63, 66, 70, 71, 74 and 75%). The progressive motility after CASA analysis in Fuc+Tre group was also higher than those in fructose, trehalose, xylose, Fru+xyl, Tre+xyl and Fru+Tre+Xyl (67% vs. 53, 57, 60, 61, 62 and 64%). The acrosome damage of post-thaw spermatozoa stained was not significantly different among treatment groups such as fructose, trehalose, xylose, Fru+Tre, Fru+xyl, Tre+xyl and Freu+tre+xyl (17.7, 18.3, 28.0, 17.0, 19.7, 20.0 and 19.0%). The results indicated that the motility and progressive motility of post-thaw spermatozoa in Fru+Tre group was better, and acrosome normality was not different among all groups. The use of Tris-buffer supplemented with Fru+Tre as sugar for frezing of canine spermatosoa could be better and apply to semen banking and artificial insemination.

본 연구는 체내, 체외 소 배반포기 배의 GMP vitrification 후 활력도의 비교와 한우 수정란을 몽골 소에 수정란이식 후 산자생산 가능성을 조사하고자 실시하였다. 한우 수정란은 체외수정란 또는 과배란처리에 의한 체내수정란을 생산하여 GMP vitrification 방법으로 동결 후 몽고로 수송하였다. 수란우는 CIDR과 처리에 의하여 동기화를 유도하였다 체내수정란생산을 위하여 7두를 과배란처리하였다. 총 64개의 배반포기를 회수하였다. (pe

The pack-cementation process is the method which is formed SiC coating layer to improve weak oxidation properties of CFRCs (carbon fiber-reinforced carbons). This method develops the anti-oxidation coating layer having no dimensional changes and good wetting properties. In this study to improve the oxidative resistance of the prepared 4D CFRCs, the surface of CFRCs is coated by SiC using pack cementation method. The mechanical properties of SiC-coated 4D CFRCs are measured by the 3-point bending test, and their ablation properties are investigated by the arc torch plasma test. From the results, it is found that both mechanical and ablation properties of SiC-coated 4D CFRCs are much better than bare CFRCs.