Optical Control of MicroRNA Function in Zebrafish Embryos

Abstract

MicroRNAs play crucial and dynamic roles in vertebrate development and diseases. Some, like miR-430, are highly expressed during early embryo development and regulate hundreds of transcripts, which can make it difficult to study their role in the timing and location of specific developmental processes using conventional morpholino oligonucleotide (MO) knockdown or genetic deletion approaches. We demonstrate that light-activated circular morpholino oligonucleotides (cMOs) can be applied to the conditional control of microRNA function. We targeted miR-430 in zebrafish embryos to study its role in the development of the embryo body and the heart. Using 405 nm irradiation, precise spatial and temporal control over miR-430 function was demonstrated, offering insight into the cell populations and developmental timepoints involved in each process.

Optochemical Control of mRNA Translation in Eukaryotes

“…Upon irradiation antagomir function is restored and mRNA translation can occur. [48] In the final part of our review, we would like to highlight photoswitchable siRNAs, which can be de-and (re)activated. The substitution of two nucleotides within the sense strand of the siRNA with an azobenzene renders the siRNA and their RNAi function controllable by light (Figure 8).…”

“…Before irradiation, the ability of the cMO to hybridize to its target miRNA is markedly reduced. Irradiation induces miR‐430 knock‐down that manifests in shortened body lengths and heart looping defects [48] …”

“…Native miRNA inhibits the translation of the target mRNA and the corresponding antagomir is inactive. Upon irradiation antagomir function is restored and mRNA translation can occur [48] …”

o-Nitrobenzyl Oxime Ethers Enable Photoinduced Cyclization Reaction to Provide Phenanthridines under Aqueous Conditions

“…The development of photoinduced reactions that proceed under biological conditions is highly sought after for chemical biology and drug discovery studies because they offer a potent tool for perturbing and investigating biological processes in a very spatiotemporal manner. − o -Nitrobenzyl moieties are representative chemical entities that can photocontrol functional molecules; these photolabile protecting groups can be covalently attached to a molecule of interest to “cage” its function, while the reactivation can be achieved on demand by photodeprotection (Figure a). Since Hoffman’s first use of o -nitrobenzyl and its derivatives in the photocaging of ATP in 1978, they have been widely used as photochemical handles to manipulate the bioactivity of numerous bioactive molecules. − …”

o-Nitrobenzyl oxime ethers enable photo-induced cyclization reac-tion to provide phenanthridines under aqueous conditions

“…Since Hoffman's first use of o-nitrobenzyl and its derivatives in the photocaging of ATP in 1978, 4 they have been widely used as a photochemical handles to manipulate the bioactivity of numerous bioactive molecules. [5][6][7][8][9] The o-nitrobenzyl groups are typically photo-deprotected by the Norrish type II mechanism (Fig. 1a).…”