Fig. 2

Sliding window analyses of nucleotide diversity (π _T), Tajima’s D and ω. The ticks on the x axis represent the boundary of each analysed PgiC1 exon within the PgiC1 coding sequence. In F. ovina, PgiC1 exons 5–12 encode the small domain of a PGI monomer while exons 13–21 encode the large domain. The two dots on the x axis show the locations of the two PgiC1 codon sites (173 and 200) that were earlier identified as being candidates for positive diversifying selection [34]. The three stars on the x axis represent the three active site residues (equivalent to Lys516, Glu360, and His391 in F. ovina) that are directly involved in the PGI isomerization reaction [35]. The grey dotted vertical line shows the location of intron 12, which is used as the demarcation point for defining the 5’ and 3’ portions of PgiC1 sequence. The brown dotted vertical line indicates codon site 200 which is under positive diversifying selection and located at or near to peaks of π _T, Tajima’s D and ω