Marsupial Genome Sequences: Providing Insight into Evolution and Disease
Comparative map of the human and marsupial X chromosomes. The position of XIST, genes flanking XIST in eutherians, and the recently discovered opossum RSX gene are indicated. The dark grey region on the human X corresponds to the region added to the X in the eutherian lineage (XAR). A heterochromatic region of the tammar wallaby X chromosome is indicated in light grey. An activity map is shown to the right of the tammar wallaby X chromosome. Grey bars indicate the percent of nuclei displaying biallelic expression, that is, expressed from both the active and “inactive” X chromosomes.