CLONING AND EXPRESSION PATTERN OF XENOPUS PRX-1 (XPRX-1) DURING EMBRYONIC-DEVELOPMENT

Homeobox genes are expressed both temporally and spatially during vert ebrate development, and regulate the tissue-specific expression of oth er genes. A Xenopus paired-related homeobox-1 (Xprx-1) cDNA was cloned . Xprx-1 had a paired-related homeodomain, but did not contain a paire d-box. The sequence of Xprx-1 had a high level of homology with K-2(mo use) and Prx-1(chicken), thus Xprx-1 is assumed to be the Xenopus homo log of these genes. Xprx-1 transcripts were maternally restricted, in Xenopus embryos, and a decrease in the late blastula stage was followe d by an increase in zygotic transcripts after gastrulation. The transc ripts were localized to the animal hemisphere of the late blastula and were concentrated in the branchial arches of the tail-bud stage embry o. In animal cap experiments, Activin A dose-dependently induced Xprx- 1 gene expression. These results suggest that Xprx-1 plays a role in e arly Xenopus development similar to other species.