We are pleased to announce the arrival of the Rfam Track Hub for the popular UCSC Genome browser. Rfam data has been available in the Ensembl browser for some time and provides links back to the Rfam annotation, and now this same functionality is available for the UCSC Genome Browser.
The hub file is available on our ftp site, and by following the instructions at the UCSC Genome Browser Custom Hub page, you can visualise Rfam annotations for the majority of species for which genomes are provided by the UCSC Genome Browser. Clicking on a match will give you exact start and stop positions, as well as links to the Rfam annotation page here at the Sanger. At the moment, bit scores or E-values for a given match aren’t yet available directly through the UCSC Genome Browser, though we’re working on it. Happy browsing!
Rfam types for Genome annotation
Xfam (in the forms of Sarah and Rob) attended the NIH Genome Annotation Workshop last week, and it was a great insight into the trials and tribulations of coming up with common standards that everyone’s happy with. It was also nice to hear that Rfam is being used exensively to annotate ncRNA features. However, there’s been some confusion amongst annotators when converting between Rfam types (such as CD-Box) and the ncRNA_classes required by INSDC under the ncRNA feature key. The ncRNA feature key is intended to describe non-coding RNAs that aren’t ribosomal or transfer RNAs; these use the rRNA and tRNA feature keys respectively.
To use the ncRNA feature key, annotators are required to supply an appropriate ncRNA_class, and this is where confusion arises, as there’s no perfect overlap between the Rfam entry types and the ncRNA classes. To reduce this, here at Rfam we’ve put together a handy translation guide to make it easy to know what ncRNA class you should apply if you are using an Rfam family to annotate a genome. There are also some cases where an INSDC type is more specific than the Rfam type; for example, we don’t have a specific telomerase RNA type, whereas there is a ncRNA_class called telomerase_RNA. Therefore any annotation to RF00025 can use the telomerase_RNA ncRNA_class category. You can find our table of Rfam types and their INSDC equivalents here.