Wallaroos (Macropus robustus robustus), which have the G6PD-F electrophoretic 
phenotype, crossed with euros (M.r.erubescens), of G6PD-S phenotype, produced F1 
animals which had only the maternal G6PD type regardless of the direction of the 
cross. When F1 hybrids were backcrossed to wallaroos or euros, backcross progeny 
of either perental phenotype resulted. Sex-linked inheritance of allelic G6PD 
genes is shown to occur in wallaroos, euros and red kangaroos (M. rufus). Dose 
compensation for X chromosomes at the G6PD locus in kangaroow is achieved by 
inactivation of the allele of male parental origin.