Micropterigidae is regarded as the sister group of all the other Lepidoptera, providing important insights into the evolution of Lepidoptera. However, the gene and protein profiles of silk from Micropterigidae have not yet been identified. In this study, we investigate the components of silk cocoons of the micropterigid species Neomicropteryx cornuta. Here we show that the protein fibroin heavy chain (FibH) is absent in the silk of N. cornuta and that the putative homolog of fibroin light chain (FibL) is also absent or severely altered. This is confirmed by transcriptome and genome analyses of the conserved regions in this species. The examination of the synteny around the fibH genes in several Lepidoptera and Trichoptera species shows that the genomic region containing this gene is absent in another micropterigid species, Micropterix aruncella. In contrast, we found putative orthologs of fibH and fibL in the representative transcripts of another distinct clade, Eriocraniidae. This study shows that the loss of FibH and the loss or severe divergence of FibL occurrs specifically in the family Micropterigidae and reveals dynamic evolutionary changes in silk composition during the early evolution of Lepidoptera. It also shows that silk proteins without FibH can form a solid cocoon.

Biology Centre of the Czech Academy of Sciences Institute of Entomology Ceske Budejovice 37005 Czech Republic

Faculty of Science University of South Bohemia Ceske Budejovice 37005 Czech Republic

Institute of Molecular Genetics Academy of Sciences of the Czech Republic Praha 142 20 Czech Republic

Kyoto University Graduate School of Science Kyoto 606 8502 Japan

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Kenchington, W. Biological and chemical aspects of silks and silk-like materials produced by arthropods.

Sutherland, T. D., Young, J. H., Weisman, S., Hayashi, C. Y. & Merritt, D. J. Insect silk: one name, many materials. PubMed DOI

Beutel, R. G., Friedrich, F., Ge, S.-Q. & Yang, X. K.

Kristensen, N. P. e.

Sehnal, F. & Zurovec, M. Construction of silk fiber core in lepidoptera. PubMed DOI

Akai, H. In

Kludkiewicz, B. et al. The expansion of genes encoding soluble silk components in the greater wax moth, Galleria mellonella. PubMed DOI

Takasu, Y., Yamada, H. & Tsubouchi, K. Isolation of three main sericin components from the cocoon of the silkworm. PubMed DOI

Rouhova, L. et al. Comprehensive analysis of silk proteins and gland compartments in Limnephilus lunatus, a case-making trichopteran. PubMed DOI PMC

Rouhova, L. et al. Using the multi-omics approach to reveal the silk composition in Plectrocnemia conspersa. PubMed DOI PMC

Fedic, R., Zurovec, M. & Sehnal, F. Correlation between fibroin amino acid sequence and physical silk properties. PubMed DOI

Heckenhauer, J. et al. Characterization of the primary structure of the major silk gene, h-fibroin, across caddisfly (Trichoptera) suborders. PubMed DOI PMC

Yonemura, N., Mita, K., Tamura, T. & Sehnal, F. Conservation of silk genes in Trichoptera and Lepidoptera. PubMed DOI PMC

Zurovec, M. et al. Functional conservation and structural diversification of silk sericins in two moth species. PubMed DOI

Regier, J. C. et al. A molecular phylogeny for the oldest (nonditrysian) lineages of extant Lepidoptera, with implications for classification, comparative morphology and life-history evolution. DOI

Shimura, K., Kikuchi, A., Ohtomo, K., Katagata, Y. & A, H. Studies on silk fibroin of Bombyx mori. I. Fractionation of fibroin prepared from the posterior silk gland. PubMed DOI

Kawahara, Y. et al. Comprehensive study on the formation of higher-order structure of bombyx mori silkworm fibers: influence of sericin fractions, modulation of spinning process, and metal ion interactions. DOI

Liao, C. Q. et al. Higher-level phylogeny and evolutionary history of nonditrysians (Lepidoptera) inferred from mitochondrial genome sequences. DOI

Hu, W. B., Lu, W., Wei, L. W., Zhang, Y. & Xia, Q. Y. Molecular nature of dominant naked pupa mutation reveals novel insights into silk production. PubMed DOI

Mase, K., Iizuka, T., Okada, E., Miyajima, T. & Yamamoto, T. A new silkworm race for sericin production, “SERICIN HOPE” and its product, “VIRGIN SERICIN”.

Wu, B. C. et al. Characterization of silk genes in Ephestia kuehniella and Galleria mellonella revealed duplication of sericin genes and highly divergent sequences encoding fibroin heavy chains. PubMed DOI PMC

Teshome, A., Vollrath, F., Raina, S. K., Kabaru, J. M. & Onyari, J. Study on the microstructure of African wild silk cocoon shells and fibers. PubMed DOI

Davis, D. R. & Landry, J. F. A review of the North American genus Epimartyria (Lepidoptera, Micropterigidae) with a discussion of the larval plastron. PubMed DOI PMC

Klausnitzer, B., Meyer, E., Kössler, W. & Eisenbeis, G. On the larval morphology of micropterix arincella (Scopoli, 1763).

Wang, X., Li, Y., Liu, Q., Xia, Q. & Zhao, P. Proteome profile of spinneret from the silkworm, Bombyx mori. PubMed

Heath, J. In

Imada, Y., Kawakita, A. & Kato, M. Allopatric distribution and diversification without niche shift in a bryophyte-feeding basal moth lineage (Lepidoptera: Micropterigidae). PubMed PMC

Levine, J. D., Sauman, I., Imbalzano, M., Reppert, S. M. & Jackson, F. R. Period protein from the giant silkmoth Antheraea pernyi functions as a circadian clock element in Drosophila melanogaster. PubMed DOI

Rouhova, L. et al. Silk of the common clothes moth, Tineola bisselliella, a cosmopolitan pest belonging to the basal ditrysian moth line. PubMed DOI

Afgan, E. et al. The Galaxy platform for accessible, reproducible and collaborative biomedical analyses: 2018 update. PubMed DOI PMC

Simao, F. A., Waterhouse, R. M., Ioannidis, P., Kriventseva, E. V. & Zdobnov, E. M. BUSCO: assessing genome assembly and annotation completeness with single-copy orthologs. PubMed DOI

Hughes, C. S. et al. Ultrasensitive proteome analysis using paramagnetic bead technology. PubMed PMC

Rappsilber, J., Mann, M. & Ishihama, Y. Protocol for micro-purification, enrichment. PubMed DOI

Cox, J. et al. Andromeda: a peptide search engine integrated into the MaxQuant environment. PubMed DOI

Hall, T. A. BioEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT.

Stothard, P. The sequence manipulation suite: JavaScript programs for analyzing and formatting protein and DNA sequences. PubMed DOI

Kumar, S., Stecher, G. & Tamura, K. MEGA7: molecular evolutionary genetics analysis version 7.0 for bigger datasets. PubMed DOI PMC

Nguyen, L. T., Schmidt, H. A., von Haeseler, A. & Minh, B. Q. IQ-TREE: a fast and effective stochastic algorithm for estimating maximum-likelihood phylogenies. PubMed DOI PMC

Kalyaanamoorthy, S. et al. ModelFinder: Fast model selection for accurate phylogenetic estimates. PubMed PMC

Xie, J. M. et al. Tree visualization by one table (tvBOT): a web application for visualizing, modifying and annotating phylogenetic trees. PubMed DOI PMC

Li, X. et al. First annotated genome of a mandibulate moth, Neomicropteryx cornuta, generated using PacBio HiFi sequencing. PubMed PMC