The Rhox genes

Homeobox genes encode transcription factors that have crucial roles in embryogenesis. A recently discovered set of homeobox genes - the Rhox genes - are expressed during both embryogenesis and in adult reproductive tissues. The 33 known mouse Rhox genes are clustered together in a single region on the X chromosome, while likely descendents of the primodial Rhox cluster, Arx and Esx1, have moved to other positions on the X chromosome. Here, we summarize what is known about the regulation and function of Rhox cluster and Rhox-related genes during embryogenesis and gametogenesis. The founding member of the Rhox gene cluster - Rhox5 ( previously known as Pem) - has been studied in the most depth and thus is the focus of this review. We also discuss the unusually rapid evolution of the Rhox gene cluster. Reproduction (2010) 140 195-213