Abstract: An unknown function cDNA clone, with full-le ng th of 1690 bp, named OsHL1, was cloned by DDRT-PCR between hybrid and its parents in rice. Sequently, it was oriented on chromosome 3 between R2393 and MRG4548. Sequence analysis showed that this cDNA encoding regions might encode 26S proteasome regulatory particle non-ATP ase subunit 5, the homology was 97%. The deduced amino acid sequence included 443 amino acid with high conservative domains, was encoded by complete open re ading frame. RT-PCR showed the expression of OsHL1 gene was reduced by ABA and MeJA stress as related to the signal transducti on. It is proposed that the hybrid vigour may be conducted and adjusted and con trolled by the signal transduction of ubiquitin pathway.

Key words: heterosis, proteasome, bioinformatics, mRNA differen tial display

摘要： 运用DDRTPCR分离获得水稻杂种一代超亲表达的cDNA片段。以此序列在日本晴cDNA全长数据库进行同源搜索，检索到一个功能未知的全长cDNA，有1690 bp，命名为OsHL1，进一步分析发现它位于3号染色体上R2393和MRG4548之间。序列分析表明，该基因与日本晴编码26S proteasome regulatory particle nonATPase subunit 5基因片段的序列同源性为97％。其中包含一个完整的开放阅读框(ORF)，编码443个氨基酸，氨基酸序列同源性分析发现高度保守区。RTPCR显示OsHL1基因的表达受到ABA和MeJA处理下调。推测杂种的表现可能与26S蛋白酶体亚基参与的信号调控相关。

关键词: 杂种优势, 蛋白酶体, 生物信息学, mRNA差异显示技术