Positions of duplicate chromosomal segments in the zebrafish genome. Each dot in the grid represents a pair of putative duplicate zebrafish genes plotted according to the map positions of the two genes. Boxes that contain multiple points represent putative duplicate chromosomal segments. Names, accession numbers, and positions of putative duplicate genes mapped in the heat shock (HS) panel and in previous work are summarized in Table 3. The distribution of points in the grid is distinctly nonrandom. The χ2 = 34.6, calculated according to Gates et al. (1999). For 1 degree of freedom, a χ2 >10.83 indicates a significant difference between a random distribution and the observed distribution at a significance level P <0.001. The map positions of zebrafish genes and ESTs summarized in the graph were derived from this study and from previous work (Amores et al. 1998;Postlethwait et al. 1998; Gates et al. 1999; Geisler et al. 1999; Kelly et al. 2000).
