Whole numbers indicate bootstrap values of 1000 replicates and branch distances are given in decimal numbers when >50%. Drosophila melanogaster Shaven, Pax5 and Pax8 proteins were used as out groups. Organisms from which each protein sequence was derived are indicated in the prefix, ca, goldfish (Carassius auratus); dr, zebrafish (Danio rerio, Pax2a_t2: NP_571259.1, Pax2a_t1: ENSDART00000076992, Pax2b: NP_571715.1, Pax5: NP_571713.1, Pax8: XP_001339893.3); ol, Japanese medaka (Oryzias latipes,Pax2: CAB09696.1); xl, African clawed frog, (Xenopus laevis, Pax2: NP_001079830.1, Pax5: NP_001079237.1, Pax8: NP_001081941.1); hs, human (Homo sapiens, PAX2A: NP_003978.2, PAX5: NP_057953.1, PAX8A: NP_003457.1); mm, mouse (Mus musculus Pax2: NP_035167.3, Pax5: NP_032808.1, Pax8: NP_035170.1); rn, rat (Rattus norvegicus, Pax2: NP_001099831.1, Pax8: NP_112403.2); gg, chicken (Gallus gallus, Pax2: NP_990124.1, Pax5: NP_989755.1); and dm, fruit fly (Drosophila melanogaster, Shaven: NP_726645.3).