Isolation and expression of two novel Wnt/wingless gene homologues in Drosophila.
Wingless (wg), the Drosophila homologue of the mouse Wnt-1 proto-oncogene, is a segment polarity gene essential in each segment for normal Drosophila development. We here report the isolation of two novel Drosophila Wnt homologues, DWnt-2 and DWnt-3, and thus the existence of a Wnt/wingless gene family in Drosophila. DWnt-2 and DWnt-3 map to chromosome 2 position 45E and chromosome X position 17A/B, respectively. DWnt-2 and DWnt-3, like the other known Wnt genes, encode amino-terminal signal peptides suggesting that the gene products are secreted proteins. The putative translation product of DWnt-2 and the carboxy-terminal half of the deduced DWnt-3 product are both rich in conserved cysteine residues. In comparison with other Wnt gene products, mostly about 40 x 10(3) relative molecular mass, the DWnt-3 protein has an extended amino terminus and a long internal insert, and its predicted relative molecular mass is 113 x 10(3). The expression patterns of these two Wnt/wg homologues are dynamic during Drosophila embryogenesis. The distribution of DWnt-2 transcripts is predominantly segmented, with the additional presence of transcripts in the presumptive gonads. Transcripts of both DWnt-2 and DWnt-3 appear to be associated with limb primordia in the embryo and may therefore specify limb development. DWnt-3 is also expressed in mesodermal and neurogenic regions. The distribution of DWnt-3 transcripts in cells of the central nervous system (CNS) during Drosophila embryogenesis suggests that DWnt-3 could be involved in CNS development.
Russell
J
J
Howard Hughes Medical Institute, Stanford University, California 94305.
Gennissen
A
A
Nusse
R
R
D000595:Amino Acid Sequence; D000818:Animals; D002490:Central Nervous System / Q000196:embryology; D002874:Chromosome Mapping / Q000379:methods; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics*; D005121:Extremities / Q000196:embryology; D015870:Gene Expression / Q000502:physiology; D005796:Genes / Q000235:genetics*; D051379:Mice; D015336:Molecular Probe Techniques; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid