D608 Nucleic Acids Research, 2010, Vol. 38, Database issue Figure 1. Literature tab. For each gene page the literature tab stores each publication citing the genes name, symbol or synonyms. Records are counted (see tab) and parsed for various key words, such a morpholino, to aid in literature sorting. titles, abstracts and image captions of published papers. These terms are extracted from surrounding punctuation and exclusions are made for common terms that would cause too many false matches (e.g. not). The link matcher searches new articles for gene symbols, names and synonyms on a weekly basis. Link matching allows us to determine which papers are associated with particular genes. Matched papers are listed in the literature tab of each gene page (Figure 1). Correspondingly, gene symbols, synonyms and names are hyperlinked inside article titles, abstracts and captions. In fact, gene matches are hyperlinked in article titles wherever they appear in Xenbase. This allows easy navi- gation back and forth between the gene catalog and publications. The linkages between genes and articles have also been exploited to create an interactants tab in the gene catalog. The interactants tab is generated by using the link- matching system to determine when multiple genes are cited in a paper. Potential interactants are ordered from those with the most co-citations to those with the least and links are provided to the source papers. Finally, we have expanded our use of the image scraping system that allows curators to automatically extract images and captions from the online version of journals. Cell, Current Biology, Development, Developmental Biology, Developmental Cell, Developmental Dynamics, Mechanisms of Development and Proceedings of the National Academy of Sciences allow Xenbase to display images depicting gene expression. GENE EXPRESSION Support for gene expression data is the largest expansion of Xenbase. Gene expression data can be accessed in two ways: via the expression tab of the gene catalog and a new expression search. The expression tab lists the anatomy terms and expression stages where evidence of expression exists for each gene. Any expression thumbnail images are organized into categories by their source and are ordered from the latest to the earliest development stage. Clicking on an expression thumbnail will display a modal window with the standard-sized version of the image (Figure 2). This window also contains a chart summarizing any associated annotations such as the devel- opment stages (5) when expression occurs and XAO terms for tissues where expression occurs. Additional infor- mation may include a caption, copyright information, a link to a large image and a permanently linkable page. Indeed, clicking on an image anywhere in Xenbase will pull up a modal image box with this information. Users can navigate directly to the previous or next image in the series from the expression tab by clicking on the right or left side of the modal dialog box. An expression search feature complements the expres- sion tab by allowing users to search for expression patterns using a broad criteria and ﬁnd expression patterns for clones not yet mapped to a gene. Users can search expression by a combination of gene name, devel- opment stages, XAO anatomy terms, data source type, experimenter and assay type or source type (Figure 3).