Structure and function of a sea urchin orthodenticle-related gene (HpOtx)

Abstract

Two distinct types of orthodenticle-related proteins (HpOtx(E/L)) have been implicated as transcription activators of the aboral ectoderm-specific arylsulfatase (Ars) gene. Here, we describe the structure of HpOtx gene and present evidence that mRNAs of HpOtx(E/L) are transcribed from a single HpOtx gene by altering the transcription start site and by alternative splicing. By transactivation experiments, we have also demonstrated that HpOtx(L) activates the Ars promoter in the gastrula-stage embryo.