Morpholino oligonucleotides

The zebrafish embryo is a very good model to investigate the role of a gene during development. Zebrafish embryos may be injected using various techniques to modulate gene expression such as knock down (morpholino antisense oligonucleotides), overexpression... 

This splicing correction assay has now been widely adopted, since it has a low background and provides a positive read-out with a large dynamic response. Neutral steric-block ON, such as peptide nucleic acids (PNA) (5) or phospho-rodiamidate morpholino oligonucleotides (PMO) (6). are particularly suitable for this purpose, since they cannot recruit RNase H, they hybridize with high affinity and selectivity to complementary RNA, and they are metabolically very stable. However, they cannot be transfected with most commercially available delivery vectors. 

Oligonucleotide (also termed oligos) Usually a sequence of DNA or RNA with a phosphate backbone (Fig. IB), but may have a sulfate, peptide, or morpholino backbone in place of a phosphate one, to reduce or eliminate oligo degradation by nucleases. 

Studies with PNA analogs have shown that these analogs can inhibit translation in cell-free systems, but to date no data have been reported from cellular studies (114,115). For morpholino oligomers, antisense activity has been reported in both cell-free and cellular assays (116, 117). Numerous oligonucleotides... 

Sinha N, Biernat J, Koster H. Cyanoethyl iV,iV-dialkylamino N-morpholino-monochloro phosphoamidites. New phosphitylating agents facilitating ease of deprotection and work-up of synthesized oligonucleotides. Tetrahedron Lett 24 5843-5846, 1983. 

Molecular-biology-grade reagents should be used to prepare the solutions, DNA, RNA, and morpholino oligonucleotide samples. 

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