Expression of a Wnt gene in embryonic epithelium of the leech.
A new member of the Wnt class of cell-cell communication molecules was identified in the leech Helobdella triserialis, on the basis of a conserved 86 amino acid coding sequence and exon structure. This gene, htr-wnt-A, is not an obvious homolog of any one of the previously described wnt class proteins. The embryonic expression of htr-wnt-A has been characterized at the cellular level, using nonradioactive in situ hybridization and polyclonal antibodies generated via a novel method of antigen presentation. Subcellular localization of the htr-wnt-A protein was examined by the use of immunofluorescence and confocal microscopy. htr-wnt-A is among the first zygotically expressed genes in Helobdella, appearing first in a single cell of the eight-cell embryo. In early development it is expressed within a stereotyped subset of micromeres and later, in a seemingly dynamic and stochastic pattern, by cells in a micromere-derived provisional embryonic epithelium. Its spatial and temporal expression pattern make it a candidate for participation in the regulation of cell fate in the O/P equivalence group.
Kostriken
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Department of Molecular and Cell Biology, University of California, Berkeley 94720.
Weisblat
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001755:Blastocyst / Q000737:chemistry; D007865:Leeches / Q000196:embryology / Q000235:genetics*; D008969:Molecular Sequence Data; D012689:Sequence Homology, Nucleic Acid; D015398:Signal Transduction / Q000235:genetics