Reference "Computational identification of novel family members of microRNA genes in Arabidopsis thaliana and Oryza sativa"

Reference ID

11274

Title

Computational identification of novel family members of microRNA genes in Arabidopsis thaliana and Oryza sativa

Source

Acta Biochim Biophys Sin (Shanghai), 2005, vol. 37, pp. 75-87

Authors (3)

Li-Y	Li-W
Jin-Y-X

Abstract

MicroRNAs (miRNAs) are a class of endogenous small RNAs that play important
regulatory roles in both animals and plants. miRNA genes have been intensively
studied in animals, but not in plants. In this study, we adopted a homology
search approach to identify homologs of previously validated plant miRNAs in
Arabidopsis thaliana and Oryza sativa. We identified 20 potential miRNA genes in
Arabidopsis and 40 in O. sativa, providing a relatively complete enumeration of
family members for these miRNAs in plants. In addition, a greater number of
Arabidopsis miRNAs (MIR168, MIR159 and MIR172) were found to be conserved in
rice. With the novel homologs, most of the miRNAs have closely related fellow
miRNAs and the number of paralogs varies in the different miRNA families.
Moreover, a probable functional segment highly conserved on the elongated stem
of pre-miRNA fold-backs of MIR319 and MIR159 family was identified. These
results support a model of variegated miRNA regulation in plants, in which
miRNAs with different functional elements on their pre-miRNA fold-backs can
differ in their function or regulation, and closely related miRNAs can be
diverse in their specificity or competence to downregulate target genes. It
appears that the sophisticated regulation of miRNAs can achieve complex
biological effects through qualitative and quantitative modulation of gene
expression profiles in plants.