Erg (landform) and western Asia, and Central Australia. In South America, ergs are limited by the Andes Mountains, but they do contain extremely large dunes in coastal Peru and northwestern Argentina. They are also found in several parts of the northeast coast of Brazil. The only active erg in North America is in the Gran Desierto de Altar () that extends from the Sonoran Desert in the northwestern Mexican state of Sonora to the Yuma Desert of Arizona and the Algodones Dunes of southeastern California. An erg that has been fixed by vegetation forms the Nebraska Sandhills (). Sand seas and dune
ERG (gene) in mature lymphocytes (types of white blood cells). Therefore, ERG may act as a regulator of differentiation of early hematopoietic cells. The Mld2 mutation, generated through an ENU mutagenesis screen, was the first non-functional allele of "Erg". Homozygous Mld2 is embryonic lethal at day 13.5. Adult mice heterozygous for the Mld2 mutation have hematopoietic stem cell defects. This means that when the ERG gene was not actively transcribed and the ERG protein produced, a mouse's hematopoietic cells were unable to function properly. Since ERG is important to the ability of the hematopoietic cells to function and self-renew, there may be