Zebrafish transposon-free region dr3.89 and the orthologous regions of four vertebrate species. Each panel shows a modified screenshot displaying a 60 kb region from the UCSC genome browser. Horizontal red bars indicate TFRs and brown ticks indicate transposons. (A) Zebrafish (chr3:24,391-24,451 kb, March 2006) including the 25.9 kb TFR dr3.89. Human proteins mapped to the zebrafish genome by chained tBLASTn are indicated in blue. (B) Human (chr7:23,450-23,510 kb, March 2006) including the 13.7 kb TFR hs7.101. Human RefSeq genes are indicated in blue. (C) Mouse (chr6:49,114-49,174 kb, February 2006) including the 9.3 kb TFR mm6.309. Mouse RefSeq genes are indicated in blue. (D) Opossum (chr8:296,183-296,243 kb, January 2006) including the 16.4 kb TFR md8.376. Human RefSeq genes mapped to the opossum genome with BLAT are indicated in blue. (E) Frog (scaffold_56:3,208-3,268 kb, August 2005) including a 14 kb region that contains no transposons (red box). Human proteins mapped to the frog genome with tBLASTn are indicated in blue.