Cytochrome c oxidase subunit Ⅱ gene(COⅡ gene) is subunit of cytochrome oxidase, which is complex Ⅳ of mitochondria electron transport system. It has been frequently used in molecular phylogenetic studies because the speed of its DNA variation is faster than that of nucleus. It is especially useful in phylogenetic study of molecular biology in insects. In this study, we cloned and sequenced COⅡ gene of mitochondria DNA from Rhabditidae family nematode. Our results showed that this gene is comprised of 696 base pairs(bp). In the analysis of similarity of this gene with other known genes of 14 species of nematodes in Rhabditida order, we identified that this gene has high similarity with that of Caenorhabditis briggsae(86.0%) and C. elegans(85.6%) in Rhabditidae family. On the meanwhile, it has very low similarity with that of Angiostrongylus cantonensis(31.8%) in Angiostrongylidae family and Metastrongylus salmi(31.6%) in Metastrongylidae family. Based on the results of this study, we suggest that this nematode is closely related with that of Caenorhabditis genus in Rhabditidae family.

Abstract
 1. 서 론
 2. 재료 및 방법
 3. 결과 및 고찰
  3.1. Rhabditidae과 선충 COⅡ 유전자 염기서열
  3.2. Rhabditidae과 선충 COⅡ 유전자와 Rhabditida목14종 선충 COⅡ 유전자의 염기서열비교분석 및서열일치도
  3.3. Rhabditidae과 선충 COⅡ gene과 Rhabditida목14종 선충 COⅡ gene를 이용한 계통수 작성
  3.4. Rhabditidae과 선충 COⅡ의 아미노산 조성 분석
 4. 결 론
 REFERENCES

• 이상몽(부산대학교 생명환경화학과) | Sang Mong Lee (Department of Life Science & Environmental Biochemistry, Pusan National University)
• 손홍주(부산대학교 생명환경화학과) | Hong Joo Son (Department of Life Science & Environmental Biochemistry, Pusan National University)
• 김근기(부산대학교 생명환경화학과) | Keun Ki Kim (Department of Life Science & Environmental Biochemistry, Pusan National University)
• 홍창오(부산대학교 생명환경화학과) | Chang Oh Hong (Department of Life Science & Environmental Biochemistry, Pusan National University)
• 박현철(부산대학교 생명환경화학과) | Hyean Cheal Park (Department of Life Science & Environmental Biochemistry, Pusan National University) Corresponding author