Identification of microRNAs and microRNA targets in Xenopus ectoderm

Purpose: The establishment of cell lineages occurs via a dynamic progression of gene regulatory networks that underlie developmental commitment and differentiation. To investigate how microRNAs (miRs) function in this process, we compared miRs and miR targets at the initiation of the two major ectodermal lineages in Xenopus. Methods: We injected Xenopus laevis embryos with noggin or constitutively active BMP4 receptor (CABR) at two-cell stage and cut animal caps at stg. 8. Isolated animal caps were grown separately till mid gastrula and processed for either RNA isolation or immunoprecipitation. Results: We have identified over 400 miRNAs in early neural and epidermal ectoderm. The Ago-RNP RNAs from these tissues represent overlapping, yet distinct, subsets of genes. Moreover, the profile of Ago-RNP associated genes differs substantially from the profile of total RNAs in these tissues. Overall design: Identification of microRNAs and microRNA targets in establishment of early ectodermal tissues in Xenopus.