G-QUADRUPLEXES CONTROL THE EXPRESSION OF DEVELOPMENTALLY REGULATED GENES IN VIVO

ALDANA DAVID; EZEQUIEL MARGARIT; NORA B CALCATERRA; PABLO ARMAS

Mar del Plata

Congreso; SAIB; 2015

Genomic DNA may transiently fold as G-quadruplex (G4), a non-canonical structure associated with gene expressioncontrol and genome integrity. Although G4 formation and function was demonstrated in vitro and in cellulo, invivo biological relevance of this structure is still elusive. To approach this, we used zebrafish embryonic developmentas an in vivo model to assess the role of G4 on the transcription of conserved developmentally regulated genes. Inprevious studies we found three developmentally regulated genes containing conserved putative quadruplexsequences (PQS) within their promoters (-1000 bp) that formed G4 in vitro. Here we present in cellulo data obtainedby cloning human and zebrafish PQS upstream a basal promoter controlling firefly luciferase transcription inneuro2A cell line, which reveal a transcriptional enhancer role for all tested G4. Furthermore, the in vivo role of theseG4 was analyzed by specific disruption microinjecting antisense oligonucleotides in zebrafish embryos. This strategyled to transcriptional reduction of the analyzed genes measured by RT-qPCR and morphological changes previouslyreported for the loss of function of these genes. Overall, this study indicates that G4 display a function in vivo andmay act as conserved gene expression fine-tuning elements during embryonic development.