Lepidopteran wing scales contain abundant cross-linked film-forming histidine-rich cuticular proteins

Abstract

Scales are symbolic characteristic of Lepidoptera; however, nothing is known about the contribution of cuticular proteins (CPs) to the complex patterning of lepidopteran scales. This is because scales are resistant to solubilization, thus hindering molecular studies. Here we succeeded in dissolving developing wing scales from Bombyx mori, allowing analysis of their protein composition. We identified a distinctive class of histidine rich (His-rich) CPs (6%–45%) from developing lepidopteran scales by LC-MS/MS. Functional studies using RNAi revealed CPs with different histidine content play distinct and critical roles in constructing the microstructure of the scale surface. Moreover, we successfully synthesized films in vitro by crosslinking a 45% His-rich CP (BmorCPR152) with laccase2 using N-acetyl- dopamine or N-β-alanyl-dopamine as the substrate. This molecular study of scales provides fundamental information about how such a fine microstructure is constructed and insights into the potential application of CPs as new biomaterials.

Genome-Wide Identification and Transcriptome-Based Expression Profile of Cuticular Protein Genes in Antheraea pernyi

“…The heat maps of transcripts for each CP gene in A. pernyi confirm the tissue-specific expression pattern ( Figure 7 A), as previously reported in other insects [ 7 , 36 , 42 ]. For example, ApCPH1–2 genes were dominantly expressed in the midgut.…”

LC-MS-based detection of silkworm pupae in feed with and without prior immunoaffinity enrichment

“…Among them were 45 of 48 proteins recently identified as potential allergens (Barre et al, 2021;Jeong et al, 2022;Wang et al, 2016;Zhao et al, 2015). Similar proteomic results were observed with various tissues and stages (Levin et al, 2020;Li et al, 2009;Liu et al, 2021;Mao et al, 2018;Ye et al, 2019;Zhang et al, 2014Zhang et al, , 2018Zhang et al, , 2019. Enlarging the database by including genome-and transcriptome-derived sources as well may increase identifications up to 24% further (Levin et al, 2020), but was not our focus here.…”

“…Though MS-based proteomics was e.g. employed to verify B. mori genome and transcriptome annotations (Levin et al, 2020;Ye et al, 2019) and permitted insights into its development (Li et al, 2009(Li et al, , 2010Liu et al, 2021;Zhang et al, 2014), physiology (Masson et al, 2018;Shi et al, 2015;Zhang et al, 2014Zhang et al, , 2018, infection biology (Mao et al, 2018;Zhang et al, 2019), and allergenicity (Barre et al, 2021;Jeong et al, 2022;Wang et al, 2016;Zhao et al, 2015), proteome-based interspecies comparisons were only made for archaeological silk authentication (Gu et al, 2019) and cross-species allergen identification (Barre et al, 2021).…”

A Core Structural Protein That Builds the Locust Mandible with a Mechanical Gradient

“…Moreover, several His-rich SPs have been identified in other terrestrial arthropods including Bombyx mori , Spodoptera litura , Propsilocerus akamusi, Ostrinia furnacalis , Cupiennius salei , , etc. In B. mori , His-rich SPs play distinct and critical roles in the construction of the microstructure of the scale surface . In spider fangs, His-rich SPs cross-link Zn ions to confer hardness to the fang. , Given its multifunctional nature, Lm MHSP and its derived peptides can be considered to be potent materials for biomimetic engineering for the fabrication of mechanically graded rigid biomaterials.…”

“…In B. mori, His-rich SPs play distinct and critical roles in the construction of the microstructure of the scale surface. 43 In spider fangs, His-rich SPs cross-link Zn ions to confer hardness to the fang. 29,47 Given its multifunctional nature, LmMHSP and its derived peptides can be considered to be potent materials for biomimetic engineering for the fabrication of mechanically graded rigid biomaterials.…”