Figure 4.

Syntenic analysis of the AR in fish. We used the rose window method as described in Jaillon et al. [1] and Brunet et al. [18] (see also Additional file 3). (A) Rose window showing the 21 Tetraodon chromosomes, illustrating the two-by-two relation between duplicates originating from the teleost specific WGD event. AR-A and AR-B in Tetraodon are located respectively on chromosome T1 and T7, chromosomes that have been described as originating from the teleosts WGD. The red line shows the relationship between these two genes. (B and C) relationship between the genes present in Tetraodon chromosomes T7 (B) and T1 (C) with the genes present in the 25 zebrafish chromosomes. As shown in panel B, the AR A gene is found in the zebrafish on chromosome Z5 (red line) and a very strong synteny exists in general between T7 and Z5 chromosomes. As shown in panel C, a clear synteny is found between T1 and the Z14 chromosomes, although less univocal than in the previous case (orthology based from Ensembl v48, in agreement with reciprocal best-hit analyses we performed, data not shown). Importantly, the AR-B ortholog in the zebrafish could not be detected neither on chromosome Z14 nor on other locations in the whole genome. (D) Table indicating the positions and Ensembl accession numbers of the relevant AR genes.