Itoh, M., Nakaura, M., Imanishi, T., and Obika, S. (2014) Target Gene Knockdown by 2',4'-BNA/LNA Antisense Oligonucleotides in Zebrafish. Nucleic Acid Therapeutics. 24(3):186-91.
Gene knockdowns using oligonucleotide-based approaches are useful for studying gene function in both in vitro cell culture systems and in vivo animal models. We evaluated the efficacy of 22,42-bridged nucleic acids (BNA)-modified antisense oligonucleotides (AONs) for gene knockdown in zebrafish. We used the tcf7l1a gene as a model for testing the knockdown efficacy of 22,42-BNA AONs and examined how the target sites/affinity and RNase H induction activity of 22,42-BNA AONs affect knockdown efficacy. We found that tcf7l1a gene function was knocked down by 22,42-BNA AONs that target the start codon and induce RNase H activity. Although nonspecific p53-mediated developmental defects were observed at higher doses, the effective dose of the 22,42-BNA AONs for tcf7l1a is much lower than that of morpholino oligonucleotides. Our data thus show a potential application for 22,42-BNA AONs in the downregulation of specific genes in zebrafish.