Comparative analysis of defensin clusters among the chicken, mouse, and human. The gene clusters were drawn proportionally according to their sizes. Each vertical line/bar represents the position of a gene, and the width of each line/bar is proportional to the size of each gene. Three highly conserved genes (CTSB, BE072524, and HARL2754) surrounding the defensin clusters in the chicken, mouse, and human were connected by solid lines. The position of the α-defensin locus (DEFA) was indicated as an open square. Note that the human θ-defensin pseudogene resides in the DEFA locus. The positions and orders of defensin genes in human and mouse were drawn based on the genome assemblies released in July 2003 and October 2003, respectively. Abbreviations: GGA, chicken chromosome; MMA, mouse chromosome; HSA, human chromosome; Tel, telomere; Cen, centromere.