Analysis of the dopamine receptor family in the compact genome of the puffer fish Fugu rubripes.

The genome of the puffer fish, Fugu rubripes (Fugu), is approximately 400 Mb, 7.5 times smaller than that of human. We have isolated four dopamine receptor-like genes from Fugu genomic DNA. These genes show high sequence and structural homology to the known dopamine receptor genes, although, in contrast to previously described genes from this species, the intron size is comparable to that in human. The 5' noncoding exons of the D2/D3 dopamine receptor-like genes is described and compared to that in human. The high gene density of Fugu is shown by the close proximity of a cystatin-like gene 1503 bp from the dopamine receptor gene D222. We propose that the compact genome of Fugu can serve as a model for identifying gene family members directly from genomic DNA.