Evolutionary relationships of fimbrial subunit proteins identified in Gallibacterium strains. A total of 151 amino acid positions were used to infer the evolutionary relationship of 51 aligned fimbrial subunit proteins. Data was analyzed using the Neighbor-Joining method and conducted in MEGA6. Bootstrap values (1000) of more than 90 are displayed next to the branches. The scale represents the number of amino acid substitutions per site computed using the Poisson correction method. Fimbrial subunit proteins were classified into 5 phylogenetically distinct groups (FlfA, Flf1A, Flf2A, Flf3A and Flf4A) shown in different colors.