Cell division orientation in animals.

Cell division orientation during animal development can serve to correctly organize and shape tissues, create cellular diversity or both. The underlying cellular mechanism is regulated spindle orientation. Depending on the developmental context, extrinsic signals or intrinsic cues control the correct orientation of the mitotic spindle. Cell geometry has been known to be another determinant of spindle orientation and recent results have shed new light on the link between cellular shape and cell division orientation. The importance of controlling spindle orientation is manifested in neurodevelopmental defects such as microcephaly, tumor initiation as well as defects in tissue architecture and cell fate misspecification. Here, we summarize the role of oriented cell division during animal development and also outline the cellular and molecular mechanisms in selected invertebrate and vertebrate systems.