Phylogenetic tree of the LRR domains of PSA genes located on chromosome 12. A phylogenetic tree was inferred by PhyML for a DNA alignment of the LRR domain (see Additional files 9 and 13 for protein and DNA alignments, respectively) of all Chr 12 PSA genes of L. braziliensis, L.major and L. infantum. Bootstrap values (from 500 replicates) greater than 74% are indicated. Very similar trees (with same significant clustering of genes) were obtained with DNA or protein sequence alignments and by maximum likelihood or distance methods (not shown). SP: signal peptide; #LRR: number of LRR repeats. T/S: number of Thr and Ser residues in the Thr-rich domain (or Ser-rich, indicated by (S)). CRTM: cysteine-rich and C-ter transmembrane domains. GPI: GPI anchor. Filled and open squares indicate the presence or absence of the above features, respectively.