Comparisons of the Fugu and human Epo loci. (A) The transcription start site is shown by an arrow. Exons are shown as rectangles and introns shown as thin lines. The sizes of introns are shown. (B) Genes are shown as arrows, with the syntenic genes shown as filled arrows. The gene order at the human locus on Chr7 was obtained from the UCSC Human Genome Browser (http://genome.ucsc.edu). The human gene for 2700038N03Rik was identified in this study.