Distributions of tissue-specific genes in the human genome and testis-specific genes therian genomes.

<p>(A) Proportions of tissue-specific genes on the human X chromosome and autosomes, respectively: br, brain; cb, cerebellum; ht, heart; kd, kidney; lv, liver; non, no tissue-specificity; and ts, testis. Statistically significant differences as assessed by Fisher exact test are indicated: *two-tailed <i>p</i><0.05; *two-tailed <i>p</i><0.01. (B) Density plots of testis-specificity index for genes on the human X chromosome and autosomes. (C) Proportions of testis-specific genes on therian X chromosomes and autosomes, for all expressed genes (ALL), “recent” genes ([REC], i.e., all genes except 1∶1 orthologs present on both the current chromosomes and ancestral/proto chromosomes), and “old” genes ([OLD], i.e., 1∶1 orthologs present on both the current chromosomes and ancestral/proto chromosomes). Species: hsa, human (<i>Homo sapiens</i>); ptr, chimpanzee (<i>Pan troglodytes</i>); ppa, bonobo (<i>Pan paniscus</i>); ggo, gorilla (<i>Gorilla gorilla</i>); mml, macaque (<i>Macaca mulatta</i>); mmu, mouse (<i>Mus musculus</i>); mdo, opossum (<i>M. domestica</i>).