The production of insoluble glucan was affected by the concentration of ions and buffers in a mouth. In this study, the effects of ions and buffers on the mRNA expression of gtfB and gtfC gene of Streptococcus mutans which is an important causative agent of dental caries were investigated by Fluorescent in situ hybridization(FISH). The mRNA of gtfB and gtfC gene was normally expressed in the BHI broth containing 1 % sucrose. The gtfB and gtfC mRNA expression was increased at 0.25 mM and 4 mM of CaCl2, respectively. While the mRNA expression of two genes was inhibited at each concentration of KCl and MgCl2 when compared to the control. As for buffers, the gtfB and gtfC mRNA expression was lower than the control by the addition of sodium bicarbonate. The addition of sodium phosphate decreased the gtfB mRNA expression except for 100 mM in which the expression was increased, and the gtfC mRNA expression was similar to or lower than the control at each concentraion of sodium phosphate. The mRNA expression of the gtfB and gtfC was decreased at each concentration of potassium phosphate when compared to the control.

I. 서론
 II. 연구재료 및 방법
  1. 세균 배양
  2. 용액의 제조
  3. Oligonucleotide probe 제조
  4. 세균 고정 및 전처리
  5. Fluorescent In Situ Hybridization (FISH) 및 분석
 III. 연구 성적
  1. gtfB 및 gtfC 유전자의 mRNA 발현
  2. gtfB 및 gtfC 유전자의 mRNA 발현에 대한 Ca,K, Mg 이온의 영향
  3. gtfB 및 gtfC 유전자의 mRNA 발현에 대한완충액의 영향
 IV. 총괄 및 고찰
 V. 결론
 VI. 참고문헌

• 김민경(부산대학교 치과대학 구강미생물학교실) | Min Kyung Kim
• 박혜련(구강병리학교실) | Hae Ryun Park
• 정진(부산대학교 치과대학 구강미생물학교실) | Jin Chung correspondence