Genome-Wide Identification and Expression Profiling of Wnt Family Genes in the Silkworm, .

Wnt is a family of conserved glycoproteins that participate in a variety of important biological processes including embryo development, cell proliferation and differentiation, and tissue regeneration. The Wnt family is a metazoan novelty found in all animal phyla. Studies have revealed that the number of genes varies among species, presumably due to reproduction and loss of genes during evolution. However, a comprehensive inventory of genes in Lepidoptera is lacking. In this study, we identified the repertoire of genes in the silkworm and seven other species of Lepidoptera and obtained eight genes (, ⁻, ⁻, and ) in each species. Four of these genes are clustered in two orientations (5'-----3' and 5'-----3') in both moths and butterflies. Transcript analysis of in silkworm embryonic stages showed that each gene had a unique expression pattern during embryological development. Analysis of a larval stage revealed differential expression of family members in diverse tissues. Our study provides an overview of the family in Lepidoptera and will inspire further functional study of the genes in the silkworm.