IBR   13079
INSTITUTO DE BIOLOGIA MOLECULAR Y CELULAR DE ROSARIO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
DIVERSIFICATION OF THE MIR396 REGULATORY NETWORK DURING EVOLUTION IN PLANTS
Autor/es:
DEBERNARDI, JUAN MANUEL; RODRIGUEZ, RAMIRO ESTEBAN; MECCHIA, MARTIN; PALATNIK, JAVIER F
Lugar:
Pto Madryn
Reunión:
Congreso; XLVI Reunión Anual de la Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular; 2010
Resumen:
MicroRNAs are ~21 nt small RNAs that negatively regulate gene expression. Many of them can be grouped into families encoding similar or identical microRNAs. More than twenty microRNA families are deeply conserved in seed plants and regulate key aspects of plant biology. We present a detailed evolutionary analysis of the conserved microRNA miR396 network in plants. This miRNA regulates transcription factors of the GROWTH REGULATING FACTORS (GRF) family, which have been shown to play important roles in the regulation of cell division in plants. Through a survey for variations in the miRNA sequences of family members in different species, we found species specific miR396 variants with differences in the 5’ portion of the miRNA, a region known to be important for miRNA activity. Expression in Arabidopsis thaliana of these small RNAs revealed that some variants have specialized to regulate the GRFs with high efficiency. We also found that the miR396 regulatory network has expanded in the Brassicaceae family to regulate a basic-Helix-Loop-Helix (bHLH) transcription factor. The regulation of this novel target is important to Arabidopsis development. Expression studies have shown that miR396 coordinates the temporal expression of the GRFs and bHLH transcription factors. The emerging picture is that conserved microRNA regulatory networks could be more dynamic than previously thought.