To investigate molecular changes during the ripening of oriental melon (Cucumis melo var. kuwata) and to isolate a fruit-specific, ripening up-regulated gene, differential screening was done. 8 cDNAs corresponding to mRNAs whose abundance were increased during ripening were isolated, among them were 1-Aminocyclopropane-1-carboxylate oxidase (ACC OXIDASE), Abscisic acid, stress, ripening regulated gene homologue (ASR gene), and polyubiquitin. The other cDNAs showed no significant homology with known protein sequence. The expression pattern and genomic structure of a cDNA clone which showed homology with ASR gene was characterized. Expression of isolated ASR homologue was fruit specific, and could be detectable during Immature Green stage, increased till Ripe stage, and slightly decreased during Over Ripe stage. Southern blot analysis revealed there are low copies of ASR gene homologue in oriental melon genome. Full cDNA sequence of ASR gene homologue was obtained by Rapid Amplification of cDNA End.
참외 과육의 성숙단계에서 과육에 특이적으로 과량 발현되는 유전자와 그 promoter를 분리하기 위해 참외 과육 cDNA library에서 differential screening을 수행하여 ACC oxidase, ASR gene homologue, polyubiquitin을 포함하는 8개의 positive clone을 얻었다. ASR gene homologue의 expression pattern과 genomic structure를 분석하여서 ASR gene homologue가 과육에 특이적으로 발현되며, 과육의 성숙이 진행될수록 발현양이 증가함을 확인하였고, 참외의 genome 상에 적은 수로 존재함을 확인하였다. RACE를 통해 ASR gene cDNA의 전체 염기 서열을 밝혔다.
