Methods to analyze microRNA expression and function during Xenopus development.

microRNAs are a class of small noncoding RNAs that regulate gene expression at a posttranscriptional level. microRNAs are transcribed as primary transcripts, characterized by specific hairpin secondary structure that undergo stepwise processing to yield mature microRNAs of approximately 22 nt length. The function of the majority of vertebrate microRNAs has not yet been established and Xenopus offers a powerful system to test their biological function. Working with microRNAs is based on well-established protocols for the detection of mRNAs and manipulation of gene expression; however, the small size of mature microRNAs and their unique biogenesis require modifications to the existing protocols. Here, we present methods that can be used to detect, overexpress, and inhibit microRNAs in Xenopus tropicalis.