WNT4 gene structure in the tammar. a) The tammar wallaby WNT4 gene consists of 5 exons. The black blocks represent the exons 1–5, of 90bp, 236bp, 132bp, 143bp and 561bp respectively. The size of intron 1 and 2 are unknown while intron 3 and 4 are 154bp and 575bp accordingly; b) Southern blotting of genomic DNA. Male and female genomic DNA was digested with Eco RI, Sal I + Xbal I, respectively, and hybridized with [α-32P]dCTP-labelled tammar WNT4 cDNA probe.