Abstract: One of the U2snRNA genes in rice ( Oryza sativa L. ), FDRGU2.3, has been isolated and sequenced. By comparison, rice U2RNA had more than 80% s'unilarity with other plant U2RNAs. It was found that the 70 nucleotides of 5'-terminal were conserved in all sequenced plant U2RNAs. The rice U2.3 gene contained two plant UsnRNA promoter elements,i.e, the upstream sequence element (USE) and TATA-like box, in the - 70 and - 30 regions respectively; the spacer between the two upstream elements were conserved in the plant U2snRNA genes. The U2.3RNA maintains the conserved U2snRNA secondary structure including four stem-loops. The nucleotide sequence of loop Ⅱ was the same as that of monocot such as wheat ( Triticum aestivum L. ) and maize ( Zea mays L. ), but distinct from that of dieot such as pea ( Pisum sativum L. )and Ambidopsis thaliana (L.) Heynh. The nucleofide sequence of loop Ⅳ showed a different variation in monoeot and dicot. These suggested that the splicing apparatus between monoeot and dicot were different.

Key words: U2snRNA, Sequence analysis, Second structure