Bacillus thuringiensis 1-3 (Bt 1-3), belonging to subsp. aizawai (H7), showed different characteristics in plasmid profiles from type strain and had cry2A gene in addition to cry1Aa, cry1Ab, cry1C and cry1D. To clone its plasmids and construct E.coli-Bt shuttle vector, we constructed the plasmid capture system (PCS) by inserting attB sites including lacZ between transposable elements (designated as pPCS-Troy). Through in vitro transposition with total plasmids DNA of Bt 1-3, 53 clones were acquired and their sizes were approximately 10 kb. Based on the sequence analysis, they were classified in four groups showing similarities with four known Bt plasmids, pGI3, pBMB175, pGI1 and pGI2, respectively. One of pGI3-like clones, named as pBt1-3, was fully sequenced and its putative open reading frames (ORFs), Rep-protein, double-strand origin of replication (dso), single-strand origin of replication (sso), have been identified. The structure of pBt1-3 showed high similarity with pGI3 which is one of rolling-circle replication (RCR) group VI family. As a donor for construction of shuttle vector, pDonr-attPEm vector harboring erythromycin resistant gene between attP sites was constructed. Through BP recombination with pPCS-Troy-cloned Bt plasmids and pDonr-attPEm, erythromycin resistant gene was transposed to Bt plasmids. This scheme proposes that in vitro transposition using pPCS-Troy and BP recombination using pDonr-attPEm can easily clone Bt plasmids and construct novel shuttle vectors.

Bacillus thuringiensis 1-3 (Bt 1-3), belonging to subsp. aizawai (H7), showed different characteristics in plasmid profiles and had cry2A gene in addition to cry1Aa, cry1Ab, cry1C and cry1D. This strain exhibited dual insecticidal activity against Aedes aegypti as well as Plutella xylostella. Recently, we improved the donor-s of plasmid capture system (PCS) by inserting attB sites including lacZ between transposable elements (designated as pPCS-Troy), to construct E.coli-Bt shuttle vector. Through in vitro transposition with total plasmids DNA of Bt 1-3, 53 clones were acquired and their range of sizes were approximately 10 kb. Based on the sequence analysis, they were classified in 4 groups showing similarity with 4 known plasmids, pGI1, pGI2, pGI3 and pBMB175, respectively. One of pGI3-like clones was fully sequenced and its open reading frames were analyzed. As a donor for construction of shuttle vector, pDonr-attPEm vector harboring erythromycin resistant gene between attP sites was constructed. Through BP recombination with pPCS-Troy-cloned Bt plasmids and pDonr-attPEm, erythromycin resistant gene was transposed to Bt plasmids. This scheme proposes that in vitro transposition using pPCS-Troy and BP recombination using pDonr-attPEm can easily construct novel shuttle vectors with any Bt plasmids and this combined procedure can introduce foreign gengs into various circular DNA molecular.

효모(酵母)와 대장균(大腸菌)의 셔틀 벡터인 YIp5, YRp7, YEp13플라스미드를 S. cerevisiae DBY747을 수용세포(受容細胞)로 하여 원형질체 방법(方法)에 의해 형질전환(形質轉換)시킨 결과(結果), YIp5플라스미드는 형질전환체가 나타나지 않았으며, YEp13플라스미드는 DNA 당(當) , YRp7은 개(個)의 형질전환체를 얻었다. YIp5플라스미드와 YEp13플라스미드, 그리고 YIp5플라스미드와 YRp7플라스미드를 환상(環狀)플라스미드 상태(狀態)로 동시형질전환(同時形質轉換) 시켰을 때 각각 DNA 당(當) 210 및 95개(個)의 형질전환체를 얻었으며, 동일(同一) 부위(部位) 또는 다른 부위(部位)를 절단(切斷)한 선상(線狀)플라스크를 앞서와 같이 동시형질전환(同時形質轉換)시켰을때, 서로 비슷하게 DNA 당(當) 15~85개(個)의 형질전환체를 얻을 수 있었다. 이러한 결과(結果)에서 볼때 수용세포(受容細胞)를 S. cerevisiae DBY747로한 동시형질전환(同時形質轉換)에서 환상(環狀)플라스미드간(間)의 형질전환(形質轉換)이 선상(線狀)플라스미드간(間)의 형질전환(形質轉換)보다 빈도(頻度)가 높으며 선상(線狀)플라스미드간(間)의 형질전환(形質轉換)에서 미단(未端) 부위(部位)의 상이(相異)함이 큰 영향을 주지 않는 것으로 나타났다. 형질전환체의 안정성(安定性)에 있어서는 YIp5플라스미드와 YEp13플라스미드간(間)의 형질전환체가 YIp5플라스미드와 YRp7플라스미드간(間) 형질전환체에 비(比)해 안정(安定)하게 나타났는데, 이는 stringent control을 받는 ARS유전자(遺傳子)를 가진 YRp7플라스미드보다 DNA 복제(複製) 기점(起點)을 가진 YEp13플라스미드의 복제수(copy number)가 많기 때문인 것으로 생각된다.