Orthology established by Tsuge et al., 2013 (12 genes)

Orthology for ptger2a ( Chr: 17 )
Orthology for ptger2b ( Chr: 20 )
Orthology for ptger4a ( Chr: 8 )
Orthology for ptger4b ( Chr: 5 )
Orthology for ptger4c ( Chr: 2 )
Orthology for ptgir ( Chr: 15 )