The CAI Analyser Package: inferring gene expressivity from raw genomic data.
The Codon Adaptation Index (CAI) was introduced by Sharp and Li in 1987 to quantify codon usage similarities between a coding sequence and a set of reference sequences. When synonymous codons for a given amino acid exist, highly expressed genes seem to prefer some of them, according to tRNA abundance and thermodynamic issues. Some authors have described CAI-based methods to derive expressivity measures for all genes in a genome, in a computational framework. Here we present the CAIAP (CAI Analyser Package), a platform independent package of computer programs allowing the calculation of the CAI and a deep study of gene expressivity from raw gene sequences. Our approach implements and optimizes a procedure to derive the reference sequences from whole genomes and use their codon usage for CAI estimation. Moreover, a set of analysis tools are provided to perform statistical analyses and therefore to give robustness to results.


OBJECTIVE
Our efforts were aimed to produce an easy-to-use and fully automatic set of programs specifically designed for the analysis of gene expressivity and inter-species comparisons on a great number of genomes. Moreover, the output integrates information coming from functional annotations of genes. We are maintaining a web server storing our analyses for hundreds of genomes, allowing intergenomic comparison of data thanks to dedicated search engines. The CAIAP server is hosted at www4.unifi.it/scibio/bioinfo/caiap/html. The programs (maintained as Perl scripts) are also available for download at the same location.
Ramazzotti
Matteo
M
Dipartimento di Scienze Biochimiche, Università degli Studi di Firenze, viale Morgagni 50, 50134, Firenze, Italy.
Brilli
Matteo
M
Fani
Renato
R
Manao
Giampaolo
G
Degl'innocenti
Donatella
D
D000222:Adaptation, Physiological / Q000235:genetics*; D002876:Chromosomes, Bacterial / Q000235:genetics; D003062:Codon / Q000235:genetics*; D048168:Escherichia coli K12 / Q000235:genetics; D015870:Gene Expression / Q000235:genetics*; D020407:Internet; D012269:Ribosomal Proteins / Q000096:biosynthesis; D012984:Software
D003062:Codon; D012269:Ribosomal Proteins