DOI: 10.5061/dryad.4mw6m90n3
title: Silk gland transcriptome of <em>Neomicropteryx cornuta</em>

description: 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 remain unidentified. In this study, we investigated the
 components of silk cocoons of the micropterigid species Neomicropteryx
 cornuta. We characterized the silk glands and cocoons using light and
 electron microscopy, X-ray microtomography, and molecular techniques. Our
 results showed 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 was 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 showed that the genomic region
 containing this gene was 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 showed that the loss of FibH and the loss or
 severe divergence of FibL occurred specifically in the family
 Micropterigidae and revealed dynamic evolutionary changes in silk
 composition during the early evolution of Lepidoptera.
description: Total RNA samples from dissected larval (last-instar) SG and
 whole <em>T. bisselliella</em> last-instar larvae were
 extracted using TRIzol reagent (Life Technologies, Carlsbad, USA) and used
 to prepare cDNA libraries for the Illumina sequencing platform. A
 RiboMinus Eukaryote Kit for RNA-Seq (Ambion, Austin, USA) was used to
 remove rRNA, after which the poly-A mRNA was enriched with the aid of a
 Dynabeads Oligo (dT)25 mRNA Purification Kit (Thermo Fisher Scientific,
 Waltham, USA). The cDNA library was created with a NEXTflex Rapid RNA-Seq
 Kit (Bioo Scientific, Austin, USA). Sequencing was performed using a MiSeq
 (Illumina, San Diego, USA), producing sequences in the 2 × 150 nt pair-end
 format. A total of 1.6 × 107 reads were assembled and mapped to the
 <em>N. cornuta</em> publicly available genome
 <em>ASM2038319v1</em> using RNA Star, and the transcriptome
 was constructed using BRAKER3 (Galaxy Version 3.0.6+ galaxy2).
description: # Silk gland transcriptome of *Neomicropteryx cornuta*
 [https://doi.org/10.5061/dryad.4mw6m90n3](https://doi.org/10.5061/dryad.4mw6m90n3) ## Description of the data and file structure We study dynamic evolutionary changes in silk composition during the early evolution of Lepidoptera. The gene and protein profiles of silk from Micropterigidae, a group that probably split from other Lepidoptera over 300–200 million years ago, remain unidentified. We used advanced omics methods to identify the silk-related genes and their secretory products in *Neomicropteryx cornuta*. ### Files and variables #### File: Neomicropteryx_cds.fa.fasta **Description:** fasta file containing 34,384 assembled contigs received by RNA sequencing of cDNA library from *N. cornuta* silk glands. ## Code/software DNA Star, Geneious, or other bioinformatics software for sequence data analysis.