HMG-X, A XENOPUS GENE ENCODING AN HMG1 HOMOLOG, IS ABUNDANTLY EXPRESSED IN THE DEVELOPING NERVOUS-SYSTEM

We used a PCR-based subtraction cloning procedure with Concanavalin A-treated and untreated animal caps from stage 9 Xenopus embryos to search for genes the expression of which is induced during neurogenesis. One of these genes was found to encode a homolog of mammalian HMG 1 and 2, hence named HMG-X. HMG-X mRNA was maternally transmitted, up-regulated in neuroectoderm-derived tissues throughout early development, and eventually down-regulated in all adult tissues examined except ovary. Our data suggest that we have identified a gene for a member of the HMG1/2 family that could have an important role in neurogenesis.