Tandem gene arrays in A. adeninivorans. (a) Intermingled families. A. adeninivorans chromosomes are indicated on the left. Gene members of TGAs are depicted by boxed arrows colored according to their family. Family numbers refer to the Génolevures classification as shown in the legend in the box on the right. Pseudogenes are indicated by dotted lines. The GL3C4705 family is the largest one. Most of its members are tail-to-tail inverted tandem repeats, numbered from one to nine in black disks. (b) Neighbor-joining tree based on the muscle  alignment of positions one and two of the codons. Robustness of the tree is indicated by 100 bootstrap values calculated with a maximum composite likelihood model with uniform rates. Thin blue lines indicate pairs in inverted repeats of GL3C4705 family; heavy blue lines indicate relative orientation of genes in inverted repeats (see Additional file 11 for additional information).