Achaete-Scute Complex (Drosophila) Homolog-like 2

Achaete Scute homolog 2 (also known as mammalian aschaete-scute homolog 2 or Mash2) is a nuclear protein expressed specifically in the extravillous trophoblasts of developing placenta. Placental development involves control by the basic helix-loop-helix transcription factor Achaete Scute homolog 2, which may regulate HIF (hypoxia) in the formation of spongiotrophoblasts. Targeted mutagenesis of Achaete Scute homolog 2 yielded loss of function results in embryonic lethality at midgestation due to placental failure associated with a lack of spongiotrophoblasts and reduced labyrinthine trophoblast layers. In addition to healthy placental development, Achaete Scute proteins may also be involved in the determination of neuronal precursors in the central and peripheral nervous systems. Achaete Scute homolog 2 has also been implicated as a controller of intestinal stem cell fate and is essential for the maintenance of adult intestinal stem cells.