Logos for representative HMM profiles from each of the five subfamilies of GnRH receptors. The physical location of the region used to construct this HMM model, named ‘TM4 to 5′ in Additional file 3: Table S3 roughly corresponds with the C-terminal half of trans-membrane domain 4 to the C-terminus of transmembrane domain 5 (Figure 10). The relative entropy score for each position in the HMM profile is indicated by the height of stacked single-letter abbreviations for amino acids. Vertical red lines indicate the presence of an indel and pink shading to the right of the line represents an estimate of size variation for each respective indel. Logos were generated using LogoMat-M .