Deep sequencing of small RNAs in the Xenopus tropicalis gastrula

Transposable elements comprise a large proportion of animal genomes. Transcripts of transposable elements are a source for the synthesis of endogenous siRNAs and piRNAs. In order to determine if small RNAs mapped to expressed Tc1-like elements are present during early Xenopus tropicalis development, we used Illumina (Solexa) to sequence small RNAs from gastrula-stage embryos. We obtained about 17 million reads that mapped perfectly to the genome. Small RNAs mapped to selected transposable elements were characterized and the expression of selected small RNAs was experimentally verified during development. This is the first deep sequencing experiment for small RNAs in the Xenopus tropicalis gastrula. Overall design: Analysis of small RNAs expressed in the Xenopus tropicalis gastrula.