Abstract
In rice SINEs, p-SINEs have a T-stretch and OsSNs have an A-stretch at the 3' end. But it is not clear how the 3'-end sequences are determined. We have recently found that SINEs are widely distributed in Gramineae. SINEs found in wheat and barley had an A-stretch but those in maize and sorghum had a T-stretch. Furthermore, we found additional rice SINEs with a T-stretch. SINEs with an A-stretch shared a sequence TTCTC(A)6, and those with a T-stretch shared a sequence TCGAG(T)6. An enzyme(s) may recognize and bind to these 3' terminal sequences, to promote retroposition of SINEs. We also analyzed insertion sites of SINEs in the genome. We found that the proportion of members in introns showed a big difference among SINEs (1-40%). Affects on gene expression by SINE sequences or target specificity of enzymes involved in retroposition might be different among SINEs.
