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Novel traits in the order Lepidoptera include prolegs in the abdomen of larvae, scales, and eyespot and band color patterns in the wings of adults. We review recent work that investigates the developmental origin and diversification of these four traits from a gene-regulatory network (GRN) perspective. While prolegs and eyespots appear to derive from distinct ancestral GRNs co-opted to novel body regions, scales derive from in situ modifications of a sensory bristle GRN. The origin of the basal and central symmetry systems of bands on the wing is associated with the expression of theWntAgene in those regions, whereas the more marginal bands depend on two other genes,Distal-lessandspalt. Finally, several genes have been discovered that play important roles in regulating background wing color, via the regulation of pigmentation GRNs. The identification of shared and novelcis-regulatory elements of genes belonging to these distinct GRNs helps trace the developmental and evolutionary history of these traits. Future work should examine the extent to which ancestral GRNs are co-opted/modified to produce the novel traits and how these GRNs map to specific cell types in ancestral and derived traits.
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Genes with spiralian-specific protein motifs are expressed in spiralian ciliary bands
Abstract Spiralia is a large, ancient and diverse clade of animals, with a conserved early developmental program but diverse larval and adult morphologies. One trait shared by many spiralians is the presence of ciliary bands used for locomotion and feeding. To learn more about spiralian-specific traits we have examined the expression of 20 genes with protein motifs that are strongly conserved within the Spiralia, but not detectable outside of it. Here, we show that two of these are specifically expressed in the main ciliary band of the molluscTritia(also known asIlyanassa). Their expression patterns in representative species from five more spiralian phyla—the annelids, nemerteans, phoronids, brachiopods and rotifers—show that at least one of these,lophotrochin, has a conserved and specific role in particular ciliated structures, most consistently in ciliary bands. These results highlight the potential importance of lineage-specific genes or protein motifs for understanding traits shared across ancient lineages.
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- Award ID(s):
- 1656558
- PAR ID:
- 10185126
- Publisher / Repository:
- Nature Publishing Group
- Date Published:
- Journal Name:
- Nature Communications
- Volume:
- 11
- Issue:
- 1
- ISSN:
- 2041-1723
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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