1. Introduction to the
Distributed Annotation System
Biohackathon 2
Alberto Labarga –alberto.labarga@scientifik.info

2. Distributed Annotation System
• Developed in 1999/2000 by Lincoln Stein (CSHL) and
collaborators as a GFF‐based web service.
• Biodas.org (http://www.biodas.org):
• A client‐server system in which a single client
integrates information from multiple servers.
• It allows a single machine to gather up genome
annotation information from multiple distant websites,
collate the information, and display it to the user in a
single view.

3. General Feature Format
Genome annotations, especially structural annotations, are often stored in
•
GFF (General Feature Format) files.
GFF is a simple tab‐delimited data format.
•
Fields are:
•
<seqname> <source> <feature> <start> <end> <score> <strand> <frame> [attributes] [comments]
See also: http://www.sanger.ac.uk/Software/formats/GFF/
•

4. DAS Concept
Annotation server A Annotation server B Annotation server C
Client Reference server

5. DAS Registry
http://www.dasregistry.org

6. DAS Server
• DAS request to retrieve the data sources
• http://das.ensembl.org/das/dsn
• Result:

7. DAS Server
DAS request to retrieve features on a segment:
•
http://das.ensembl.org/das/ens_36_omim_genes/features?segment=1:1,1000000
•
Result:
•

8. Das viewer
http://www.ebi.ac.uk/dasty