The ras gene plays an important role in signal transduction in eukaryotes. Isolation of ras or ras-related gene from Nicotiana tabacum was attempted. Genomic DNA was screened with human c-Ha-ras as a probe and 15 positive clones were obtained. Each clone was classified into three subgroups according to its signal intensity and three clones were selected from each group. DNA was purified from those clones and digested with many types of restriction endonucleases. Southern analysis was carried out and three DNA fragments of group I and II which showed positive signal was subcloned into cloning-sequencing vector, pBluscriptIIKS+. Cloned DNA fragments were restricton endonuclease mapped.
Ras gene은 진핵세포의 신호전달체계에서 중요한 역할을 한다고 알려져 있다. 식물에서의 ras gene의 특성을 규명하기 위하여 담배(Nicotiana tabacum) genomic DNA library를 사람의 c-Ha-ras를 probe로 screening하였다. 열다섯개의 positive clone을 분리하고, 각각의 signal 강도에 따라 세가지 group으로 나누었다. 각 group에서 한가지씩의 clone에서 DNA를 분리하고 Southern hybridization 을 행하였다. Group I과 group II에서 positive signal을 보이는 세개의 restricted DNA fragment를 분리하여 cloning-sequencing vector인 pBluscriptIIKS+에 subcloning하였다. 그리고 cloning된 각각의 DNA fragment에 대해 restriction endonuclease map을 작성하였다.
