The European Nucleotide Archive (ENA; http://www.ebi.ac.uk/ena) is Europe’s primary nucleotide-sequence repository. The ENA consists of three main databases: the Sequence Read Archive (SRA), the Trace Archive and EMBL-Bank. The objective of ENA is to support and promote the use of nucleotide sequencing as an experimental research platform by providing data submission, archive, search and download services. In this article, we outline these services and describe major changes and improvements introduced during 2010. These include extended EMBL-Bank and SRA-data submission services, extended ENA Browser functionality, support for submitting data to the European Genome-phenome Archive (EGA) through SRA, and the launch of a new sequence similarity search service.

For 35 years the European Nucleotide Archive (ENA; https://www.ebi.ac.uk/ena) has been responsible for making the world’s public sequencing data available to the scientific community. Advances in sequencing technology have driven exponential growth in the volume of data to be processed and stored and a substantial broadening of the user community. Here, we outline ENA services and content in 2017 and provide insight into a selection of current key areas of development in ENA driven by challenges arising from the above growth.

To date, the majority of plant small RNAs (sRNA) have been identified in rice, poplar and Arabidopsis. To identify novel tomato sRNAs potentially involved in tomato specific processes such as fruit development and/or ripening, we cloned 4,018 sRNAs from tomato fruit tissue at the mature green stage. From this pool of sRNAs, we detected tomato homologues of nine known miRNAs, including miR482; a poplar miRNA not conserved in Arabidopsis or rice. We identified three novel putative miRNAs with flanking sequence that could be folded into a stem-loop precursor structure and which accumulated as 19-24nt RNA. One of these putative miRNAs (Put-miRNA3) exhibited significantly higher expression in fruit compared with leaf tissues, indicating a specific role in fruit development processes. We also identified nine sRNAs that accumulated as 19-24nt RNA species in tomato but genome sequence was not available for these loci. None of the nine sRNAs or three putative miRNAs possessed a homologue in Arabidopsis that had a precursor with a predicted stem-loop structure or that accumulated as a sRNA species, suggesting that the 12 sRNAs we have identified in tomato may have a species specific role in this model fruit species.

The European Nucleotide Archive (ENA; https://www.ebi.ac.uk/ena), provided from EMBL-EBI, has for more than three decades been responsible for archiving the world's public sequencing data and presenting this important resource to the scientific community to support and accelerate the global research effort. Here, we outline ENA services and content in 2018 and provide an overview of a selection of focus areas of development work: extending data coordination services around ENA, sequence submissions through template expansion, early pre-submission validation tools and our move towards a new browser and retrieval infrastructure.