Fig. 4

Comparison of the Sgs1 gene region between Drosophila species closely related to D. melanogaster. The species tree is from [33]. Branch distances are not on scale. Boxes represent coding genes. Sgs1 is in green and its neighboring genes in light gray. Introns and gene orientation are not shown. Vertical and diagonal lines between genomic sequences represent the pairwise similarity based on BLASTn analyses. They are red when BLASTn matches in the same direction and blue when BLASTn matches in the opposite direction. Shades of red and blue indicate the level of identity, with darker color for higher similarity. The minus sign on the tree branches indicates a gene deletion event