Cloning and developmental expression in Xenopus laevis of seven additional members of the Wnt family.
Degenerate oligonucleotide primers encoding highly conserved regions of Wnt-related proteins were used with the polymerase chain reaction (PCR) to amplify cDNA derived from Xenopus laevis embryos. cDNA sequences partially encoding seven additional members of the Xwnt gene family were isolated using this strategy. These cDNAs have been given the designation Xwnt-2, Xwnt-6, Xwnt-7A, Xwnt-7B, Xwnt-7C, Xwnt-8B and Xwnt-10 based on their amino acid identity with previously described Wnts. With regard to the timing of expression of these Xwnts during embryonic development, Xwnt-2, the least abundant transcript, was first detected during the neurula stage, while Xwnt-8B transcripts were first detected at the gastrula stage, and decreased by the tailbud stage. Multiple transcripts of Xwnt-6 were detected at varied times during development beginning at the gastrula stage. In contrast, Xwnt-7A, -7B and -10 transcripts were not detected until the tailbud stage. With regard to expression in adult tissues, Xwnt-6, -7A, -7B, -8B and -10 were all expressed abundantly in the brain, and to a lesser extent in a variety of other tissues. Whole-mount in situ hybridization was then employed to monitor the spatial expression of selected Xwnts. Xwnt-7A and -10 transcripts were detected in distinct areas of the developing brain of tailbud-stage embryos. The temporal and spatial differences in expression suggest different roles for these new Xwnt family members in Xenopus development.
Wolda
S L
SL
Department of Pharmacology, University of Washington School of Medicine, Seattle 98195.
Moon
R T
RT
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D015870:Gene Expression; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D011519:Proto-Oncogenes; D014158:Transcription, Genetic; D051153:Wnt Proteins; D029867:Xenopus Proteins; D014982:Xenopus laevis / Q000196:embryology / Q000235:genetics*; D029961:Zebrafish Proteins
D011518:Proto-Oncogene Proteins; D051153:Wnt Proteins; C529379:Wnt6 protein, Xenopus; C490602:Wnt8b protein, Xenopus; D029867:Xenopus Proteins; D029961:Zebrafish Proteins