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The Human and Vertebrate Analysis and Annotation (HAVANA) group at the Wellcome Trust Sanger Institute produced the manually annotated geneset for the Encyclopedia of DNA Elements (ENCODE) pilot project and, as part of the Gencode subgroup, are reprising this role in the scale up to cover the whole human genome. Our manual annotation is checked computationally and validated experimentally. Loci and transcripts predicted to be absent from the initial annotation are identified by comparison with a number of state-of-the-art algorithms for identifying exons, splice sites, transcripts and pseudogenes. Where novel features are confirmed the annotation is updated. Annotated coding transcripts are analysed to assess their coding potential by investigating patterns of conservation within the coding sequence (CDS) and comparing predicted secondary structures of annotated CDSs to similar proteins with solved structures. Annotated coding transcripts are also checked against the current set of human Consensus CDSs (CCDS) to check agreement with other participating centres (EBI, NCBI, & UCSC).An initial round of annotation and analysis of chromosomes 21 and 22 has shown that while HAVANA annotation is both comprehensive and robust, it has benefitted from computational review. 13 novel non-coding loci, 27 novel splice variants and 6 extensions to existing variants were identified, many of which were found using supporting EST/mRNA sequences that were not present at the time of initial annotation. Fewer than 10 annotated CDSs required reclassification, no CCDS sequences required updating and 26 novel pseudogene were added. The annotation of human chromosome 2 is complete and we are currently annotating chromosomes 3 and 7. Data from all members of Gencode is distributed via DAS and is now visible in our Zmap annotation interface, allowing assessment of computational predictions contemporaneous with first-pass gene annotation.

This article is part of the supplement: Beyond the Genome: The true gene count, human evolution and disease genomics, Boston, MA, USA. 11-13 October 2010., The GENCODE consortium is a sub group of the ENCODE consortium. Its aim is to provide complete annotation of genes in the human genome including protein-coding loci, non-coding loci and pseudogenes, based on experimental evidence. The final aim is for the HAVANA team to manually annotate the complete genome. This is a time-consuming process which will be completed over the course of the ENCODE project. Currently, to provide a set of annotation covering the complete genome, rather than just the regions that have been manually annotated, a merge of manual annotation from HAVANA with automatic annotation from the Ensembl automatically annotated gene set is created. This process also adds unique full-length CDS predictions from the Ensembl protein coding set into manually annotated genes, to provide the most complete up to date annotation of the genome possible. Also included in the set are short and long ncRNA genes predicted by the Ensembl prediction pipelines and a consensus set of pseudogene predictions agreed between Havana, Yale and UCSC. The CCDS set is also fully represented within the GENCODE set. The GENCODE set is the default annotation available in Ensembl and is also available in the UCSC genome browser. All the annotation is tagged as to whether it is produced by manual annotation alone, automatic annotation alone, or by both approaches. We are currently working to provide confidence levels for annotation, based on depth and type of evidence supporting it.