ISOLATION OF CDNAS PARTIALLY ENCODING 4 XENOPUS WNT-1/INT-1-RELATED PROTEINS AND CHARACTERIZATION OF THEIR TRANSIENT EXPRESSION DURING EMBRYONIC-DEVELOPMENT

To begin to study the functions of the Wnt-1 int-1 gene family during vertebrate development, we have isolated four Xenopus laevis cDNAs encoding the partial sequence of proteins homologous to Wnt-1 int-1. Xwnt-3, Xwnt-4, Xwnt-5A, and Xwnt-8 demonstrate between 35 and 50% amino acid identity with X. laevis Wnt-1 int-1 and most cysteine residues are conserved. Xwnt-4 and Xwnt-3 transcripts are detected only during the neurula through tadpole stages of development. Expression of Xwnt-8 is observable during gastrulation, declines during neurulation, and is undetectable by the tadpole stage of development. Xwnt-5A transcripts are most prevalent in RNA from oocytes and tadpoles, although low level expression is detected at all stages examined. The temporal changes in expression of these transcripts imply a unique role for each Xwnt during embryogenesis. © 1991.