Analysis of codon usage pattern and gene expression in Aspergillus fumigatus

The codon usage pattern and its impact on gene expression has been investigated in protein coding genes of Aspergillus fumigatus. Multivariate statistical analysis has been used to analyze compositional properties and codon usage pattern of genes. The results suggest that the selection of translational efficiency due to natural selection is the major factor shaping the codon usage in Aspergillus fumigatus. Using different codon usage indices as numerical estimators of gene expression level, a critical analysis has been performed to predict highly expressed (PHE) genes in Aspergillus fumigatus. The codon usage indices correlate well with the gene expression data set stem from the transcriptional responses of the micro-organisms, suggesting that codon usage is an important determinant of gene expression. We found a systematic strong correlation between NC (effective number of codons) and different expression-measures. Our study highlights the relationship between gene expression and compositional signature in relation to the codon usage bias in Aspergillus fumigatus.