MOTIVATION: To identify genetic conservation relative to precise aspects of developmental diversity, an essential question in computational biology, we developed a new comparative method that allows conserved modules for the best balance between protein sequence similarity and gene co-expression to be constructed, in invertebrates. RESULTS: Our method, referred to as the best-balance constraint procedure (BBCP), yielded 719 functionally conserved modules (FCMs) comprising 2-23 gene pairs. These modules were consistent with the developmental roles of orthologues as inferred from Gene Ontology, RNAi knockouts, InterPro and process-specific microarray data. New relationships were defined between genetic conservation and developmental diversity. Novel gene associations were indeed found in 94% of the FCMs, 150 modules being completely new. A significant proportion of the FCMs (18%, 132 modules) described cell type-specific mechanisms, comprising neuronal, muscle and germ cell signaling, new associations being found in 125 modules. Also found were gene associations for cell fate specification activities previously not highlighted by computational means, e.g. in FCMs containing homeogenes. These data indicate that highly discriminative description of genetic conservation can be deduced using BBCP, and reveal new correlations between cellular and developmental diversity and gene essentiality in invertebrates. CONTACT: [email protected] SUPPLEMENTARY INFORMATION: For supplementary information, please refer to Bioinformatics online.

SUMMARY: One of the distinguishing criteria of the SWISS-PROT protein sequence data bank is minimal redundancy. The introduction of TrEMBL as a supplementary database ensured the comprehensiveness of SWISS-PROT and TrEMBL but introduced some degree of redundancy. We developed a strategy to identify the redundancy present within and between SWISS-PROT and TrEMBL and its subsequent removal. AVAILABILITY: The tools mentioned in this paper are available on request.

MOTIVATION: This paper presents LASSAP, a new software package for sequence comparison. LASSAP is a programmable, high-performance system designed to raise current limitations of sequence comparison programs in order to fit the needs of large-scale analysis. LASSAP provides an API (Application Programming Interface) allowing the integration of any generic pairwise-based algorithm. RESULTS: Whatever pairwise algorithm is used in LASSAP, it shares with all other algorithms numerous enhancements such as: (i) intra- and inter-databank comparisons; (ii) computational requests (selections and computations are achieved on the fly); (iii) frame translations on queries and databanks; (iv) structured results allowing easy and powerful post-analysis; (v) performance improvements by parallelization and the driving of specialized hardware. LASSAP currently implements all major sequence comparison algorithms (Fasta, Blast, Smith/Waterman), and other string matching and pattern matching algorithms. LASSAP is both an integrated software for end-users and a framework allowing the integration and the combination of new algorithms. LASSAP is used in different projects such as the building of PRODOM, the exhaustive comparison of yeast sequences, and the subfragments matching problem of TREMBL.