Using Morpholinos to Control Gene Expression

Moulton, Jon D.; Yan, Yi‐Lin

Morpholino oligonucleotides are stable, uncharged, water‐soluble molecules that bind to complementary sequences of RNA, thereby inhibiting mRNA processing, read‐through, and protein binding at those sites. Morpholinos are typically used to inhibit translation of mRNA, splicing of pre‐mRNA, and maturation of miRNA, although they can also inhibit other interactions between biological macromolecules and RNA. Morpholinos are effective, specific, and lack non‐antisense effects. They work in any cell that transcribes and translates RNA. However, unmodified Morpholinos do not pass well through plasma membranes and must therefore be delivered into the nuclear or cytosolic compartment to be effective. Morpholinos form stable base pairs with complementary nucleic acid sequences but apparently do not bind to proteins to a significant extent. They are not recognized by proteins and do not undergo protein‐mediated catalysis; nor do they mediate RNA cleavage by RNase H or the RISC complex. This work focuses on techniques and background for using Morpholinos. Curr. Protoc. Mol. Biol. 83:26.8.1‐26.8.29. © 2008 by John Wiley & Sons, Inc.