본 연구는 국산 야생화초지(Native wildflower p pasture: NWP, turf grass 6종 + 국산야생화 11종) 및 외국산 야생화초지(Introduced wildflower pasture; IWP, turf grass 6종 + 외국산야생화 9종)를 조성하여 계절별 개화시간, 개화지속 정도, 꽃의 색깔, 식생변화 및 초지에서의 동물상 등을 조사 분석하여 야생화초지의 개발에 필요한 초종 선발 및 구성, 혼파조합 등의 기초자료를 얻고자

1995년 6월부터 1996년 6월까지 한강 하류 7개 정점에서 6회에 걸친 현장조사를 통하여 동물플랑크톤의 계절적 변동에 대하여 연구하였다. 조사기간중 출현한 동물플랑크톤은 총 70분류군 (taxa)으로 원생동물 3종, 윤충류 25종, 지각류 18종, 요각류 13종, 다모류 1종 등 60종이 종준위까지 동정되었다. 계절별로는 1995년 6월에 전정점에서 10~27분류군이 출현하여 가장 다양한 출현 양상을 보였으며 홍수 발생 직후인 1995년 7월에 가장 빈약하게 출현하였다. 정점별로는 상류에서 하류보다 많은 종류가 출현하는 경향을 보였다. 동물플랑크톤의 최대출현량은 입방미터당 44,317 개체(1996년 6월, 정점 7)를 기록하였으나 같은 정점에서 1995년 7월에는 전혀 출현하지 않았다. 계절별로는 1995, 1996년 모두 6월에 높은 출현량을 기록하였으며 7월과 1월에 출현량이 급격하게 감소하였다. 우점종으로는 지각류인 Daphnia galeata와 D. pulex 및 Bosmina longirostris와 요각류인 Canthocamptus carinatus, Cyclops vicinus, Thermocyclops hyalinus 및 요각류 유생이 출현하였다. 단일종으로 D. galeata가 최대 입방미터당 16,964개체의(1996년 6월, 정점 2) 농밀한 개체군을 형성하였으며 D. pulex, B. longirostris, T. hyalinus, C. vicinus도 각각 입방미터당 9,375 개체, 7,250개체, 6,714개체 및 5,772개체의 개체군이 관찰되었다. 동물플랑크톤군집의 종다양성지수는 1996년 5, 6월을 제외하고는 상류역인 정점 1~4에서 하류역인 5~7보다 높게 나타났다.

이 논문은 제주도의 산굼부리에서 채집된 날개응애 4 신종을 기재하였다. 신종은 산굼부리소매응애(Brasilobates sangumburiensis sp. nov.), 털보곰보응애(Xenillus multisetosus sp. nov.), 탐라공검둥이응애(Nippobodes tamlaensis sp. nov.), 제주공검둥이응애(Nippobodes chejuensis sp. nov.)이다.

large scale production of cloned embryos requires the technology of multiple generation nuclear transplantation(NT) using NT embryos as the subsequent donor nuclei. The purposes of this study were producing the second generation cloned rabbit embryos, and also to determine the electrofusion rate and in vitro developmental potential comparatively in the cloned embryos of the first and second NT generation. The embryos of 16-cell stage were collected from the mated does by flushing oviducts with Dulbecco's phosphate buffered saline(D-PBS) containing 10% fetal calf serum(FCS) at 47 hours after hCG injection In the first generation NT, the nuclear donor embryos were synchronized in the phase of Gi /S transition of 32-cell stage. The first generation NT embryos which were developed to 8-cell were synchronized in Gi /S transition phase of the following 16-cell stage and used as donor nuclei for second generation Synchronization of the cell cycle of blastomeres was induced, first, using an inhibitor of microtuble polymerization, colcemid for 10 hours to arrest blastomeres in M phase, and secondly, using a DNA synthesis inhibitor, aphidicolin for 1.5 to 2 hours to arrest them in Gi /S transition boundary. The recipient cytoplasms were obtained by removing the nucleus and the first polar body from the oocytes collected at 14 hours after hCG injection. The separated donor blastomeres were injected into the enucleated recipient oocytes by micromanipulation and were electrofused by electrical stimulation of three pulses for 60 sec at 1.25 kV /cm in 0.28 M rnannitol solution The fused oocytes were co-cultured with a monolayer of rabbit oviductal epithelial cells in M-199 solution containing 10% FCS for 120 hours at 39 in a 5% incubator. Following in vitro culture of the first and second generation cloned embryos to blastocyst stage, they were stained with Hoechst 33342 dye for counting the number of blastomeres by fluorescence microscopy. The results obtained were summarized as follows: 1. The electrofusion rate was found to be similar as 79.4 and 91.5% in the first and second generation NT rabbit embryos, respectively. 2. The in vitro developmental potential to blastocyst stage of the second generation NT embryos (23.3%) was found significantly(p<0.05) lower, compared with that of the first generation NT embryos (56.8%). 3. The mean blastomeres counts of embryos developed to blastosyst stage following in vitro culture for 120 hours and also their daily cell cycles during the culture period were decreased significantly (p<0.05) to 104.3 cells and 1.33 cylces in the second NT generation, compoared with 210.4 cells and 1.54 cycles in the first NT generation, respectively.

Levels of sterols including δ7-dehydrogenase isolated from the tissues of marine animal products (20 species) were determined on 1.5% OV-17 columm of gas-liquid chromatography. The composition showed that the mussels and clams contained various sterols in their tissues : cholesterol, brassicasterol. 24-methylenecholesterol with some minor components such as 22-trans-norcholesta-5,22-dien-3β-ol, 22-cis-dehydrocholesterol, 22-trans-dehydrocholesterol, desmosterol, 7-dehydrocholesterol, campesterol, stigmasterol, β-sitosterol, isofucosterol, and 7-dehydrocholesterol which could be converted into vitamin D3 in the skin tissue of animal was present in the muscle of oyster, Crassostrea gigas. On the other hand, the others including gastropoda were predominantly composed of cholesterol. The minor sterols such as 24-methylenecholesterol, stigmasterol and β-sitosterol in the fish intestines are supposed to be derived from dietary plankton. Cholesterol δ7-dehydrogenase which could convert cholesterol into δ7-dehydrogenase was present in the pickles of Tricurus haumela intestine.