Two wnt genes in Caenorhabditis elegans.
wnt genes encode secretory glycoproteins that have been implicated in growth control and development in mice, frogs and insects. In this report we examine properties of two wnt genes recently identified in the nematode Caenorhabditis elegans. The first gene, Ce-wnt-1, was previously identified by a polymerase chain reaction-based screen of genomic DNA, and the second, Ce-wnt-2, was fortuitously encountered in a survey of clones in a cDNA library by the Caenorhabditis Genome Project. Full-length or nearly full-length cDNAs representing both mRNAs encode proteins that are similar in length, sequence and functional domains to other Wnt proteins. Primary products of 372 and 362 amino acids begin with a hydrophobic signal peptide, include two potential N-linked glycosylation sites and contain the 22 cysteine residues conserved throughout the wnt family. In contrast to mammalian and insect wnt genes with four or five exons and conserved intron-exon boundaries, Ce-wnt-1 has nine coding exons; only one of the eight identified introns interrupts the coding sequence at a position homologous to an intron position in other wnt genes. The major transcript derived from Ce-wnt-1 is 1.4 kb in length, and the 22 nucleotides at its 5' end are added by a trans-splicing mechanism. Ce-wnt-2 is also expressed via a single major transcript, 1.5 kb in length. Both RNAs are detectable in all larval forms and adults, but they are most abundant at the embryonic stage. Ce-wnt-1 is localized to the left arm of chromosome II and Ce-wnt-2 maps to a cluster of genes on chromosome IV.
Department of Microbiology and Immunology, University of California San Francisco 94143.
G M
GM
Shackleford
S
S
Shivakumar
L
L
Shiue
J
J
Mason
C
C
Kenyon
H E
HE
Varmus
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000235:genetics*; D002874:Chromosome Mapping; D004247:DNA / Q000737:chemistry; D015870:Gene Expression; D017238:Genes, Helminth; D008969:Molecular Sequence Data; D011518:Proto-Oncogene Proteins / Q000737:chemistry / Q000235:genetics*; D011519:Proto-Oncogenes; D051153:Wnt Proteins; D051154:Wnt2 Protein; D029961:Zebrafish Proteins
D011518:Proto-Oncogene Proteins; D051153:Wnt Proteins; D051154:Wnt2 Protein; D029961:Zebrafish Proteins; D004247:DNA