Characterization of the primary structure of the major silk gene, h-fibroin, across caddisfly (Trichoptera) suborders

Jacqueline Heckenhauer; Russell J Stewart; Blanca Ríos-Touma; Ashlyn Powell; Tshering Dorji; Paul B Frandsen; Steffen U Pauls

doi:10.1016/j.isci.2023.107253

Characterization of the primary structure of the major silk gene, h-fibroin, across caddisfly (Trichoptera) suborders

iScience. 2023 Jul 4;26(8):107253. doi: 10.1016/j.isci.2023.107253. eCollection 2023 Aug 18.

Authors

Jacqueline Heckenhauer^{1

2}, Russell J Stewart³, Blanca Ríos-Touma⁴, Ashlyn Powell⁵, Tshering Dorji⁶, Paul B Frandsen^{1

5

7}, Steffen U Pauls^{1

2

8}

Affiliations

¹ LOEWE Centre for Translational Biodiversity Genomics (LOEWE-TBG), Frankfurt, Hesse 60325, Germany.
² Department of Terrestrial Zoology, Senckenberg Research Institute and Natural History Museum Frankfurt, Frankfurt, Hesse 60325, Germany.
³ Department of Biomedical Engineering, University of Utah, Salt Lake City, UT 84112, USA.
⁴ Facultad de Ingenierías y Ciencias Aplicadas, Ingeniería Ambiental, Grupo de Investigación en Biodiversidad, Medio Ambiente y Salud (BIOMAS), Universidad de Las Américas, Quito, EC 170124, Ecuador.
⁵ Department of Plant and Wildlife Science, Brigham Young University, Provo, UT 84602, USA.
⁶ Department of Environment and Climate Studies, Royal University of Bhutan, Punakha 13001, Bhutan.
⁷ Data Science Lab, Smithsonian Institution, Washington, DC 20560, USA.
⁸ Institute for Insect Biotechnology, Justus-Liebig-University, Gießen, Hesse 35392; Germany.

Abstract

Larvae of caddisflies (Trichoptera) produce silk to build various underwater structures allowing them to exploit a wide range of aquatic environments. The silk adheres to various substrates underwater and has high tensile strength, extensibility, and toughness and is of interest as a model for biomimetic adhesives. As a step toward understanding how the properties of underwater silk evolved in Trichoptera, we used genomic data to identify full-length sequences and characterize the primary structure of the major silk protein, h-fibroin, across the order. The h-fibroins have conserved termini and basic motif structure with high variation in repeating modules and variation in the percentage of amino acids, mainly proline. This finding might be linked to differences in mechanical properties related to the different silk usage and sets a starting point for future studies to screen and correlate amino acid motifs and other sequence features with quantifiable silk properties.

Keywords: Entomology; Genetics; Molecular biology.