Repeated Sequence Target Sites for Maternal DNA-Binding Proteins in Genes Activated in Early Sea Urchin Development
This communication concerns a very highly conserved inverted repeat sequence element that serves as a target site for a sea urchin maternal DNA-binding factor. The maternal factor is present in relatively large amounts in unfertilized eggs, but is about 100× less prevalent per embryo in 24-hr embryo nuclear extract. The inverted repeat target site is found in the regulatory domain of the CyIIIa cytoskeletal actin gene and also in two upstream genes encoding transcriptions factors that bind to a functionally important cis-regulatory element of the CyIIIa gene. There are about 460 copies of the inverted repeat target site per genome. About 15% of these sites occur in a nested arrangement together with a second inverted repeat that binds another previously characterized maternal transcription factor. This arrangement is the same as that which occurs in the CyIIIa gene, and it may be of regulatory significance with respect to activation of certain genes in oogenesis and early embryogenesis.
© 1994 by Academic Press, Inc. Accepted January 26, 1994. We thank Dr. Frank J. Calzone for providing egg and embryo extracts and Ms. Mary Chen for technical assistance. We are most appreciative of the efforts of Professor Carl Parker of this Institute who reviewed a draft of the manuscript. Research was supported by NIH Grant HD-05753. R.A. was supported by NIH Training Grant GM-07616.