Basonuclins and disco: Orthologous zinc finger proteins essential for development in vertebrates and arthropods.

Basonuclin 1 and the recently discovered basonuclin 2 are vertebrate proteins with multiple paired C(2)H(2) zinc fingers. It has long been known that the zinc fingers of basonuclin 1 closely resembled those of the Drosophila disconnected and discorelated proteins, two proteins essential for head development, but the relation between the basonuclins and the disco proteins has remained unclear because the putative function of basonuclin 1 in the control of keratinocyte growth potential appeared unrelated to that of disco and there was no resemblance between basonuclin 1 and Drosophila disco outside of the zinc fingers. The recent generation of a basonuclin-2 knockout has demonstrated that basonuclin 2 shares with disco a function in head development and the availability of new arthropod genome sequences has shown that the basonuclins are the vertebrate orthologs of the insect disco proteins. All these proteins are thought to be transcription factors, and it will have to be determined to what extent they share similar targets. Copyright Â