Lepidopteran silk is a complex mixture of proteins, consisting mainly of fibroins and sericins. Sericins are a small family of highly divergent proteins that serve as adhesives and coatings for silk fibers. So far, five genes encoding sericin proteins have been identified in Bombyx mori. Having previously identified sericin protein 150 (SP150) as a major sericin-like protein in the cocoons of the pyralid moths Galleria mellonella and Ephestia kuehniella, we describe the identification of its homolog in B. mori. Our refined gene model shows that it consists of four exons and a long open reading frame with a conserved motif, CXCXCX, at the C-terminus, reminiscent of the structure observed in a class of mucin proteins. Notably, despite a similar expression pattern, both mRNA and protein levels of B. mori SP150 were significantly lower than those of its pyralid counterpart. We also discuss the synteny of homologous genes on corresponding chromosomes in different moth species and the possible phylogenetic relationships between SP150 and certain mucin-like proteins. Our results improve our understanding of silk structure and the evolutionary relationships between adhesion proteins in the silk of different lepidopteran species.

• Klíčová slova
• Galleria mellonella, CXCXCX, Mucin, SP150, Silk glands, Synteny,
• MeSH
• bourec * genetika   metabolismus   MeSH
• fylogeneze * MeSH
• hedvábí metabolismus   genetika   chemie   MeSH
• hmyzí proteiny genetika   metabolismus   chemie   MeSH
• sekvence aminokyselin MeSH
• sericiny * metabolismus   genetika   chemie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• hedvábí MeSH
• hmyzí proteiny MeSH
• sericiny * MeSH

Many lepidopteran larvae produce silk secretions to build feeding tubes and cocoons that play important protective roles in their lives. Recent research on the silk of bombycoid and pyralid moths has shown that it contains several highly abundant silk components with remarkable mechanical properties. It was also found to contain a number of other proteins of which the functions have yet to be identified. To gain an overview of the silk composition in more primitive lepidopteran species and to identify the core silk components common to most species, we analyzed the cocoon proteins of Tineola bisselliella, which belongs to the basal ditrysian moth line. Using de novo transcriptome sequencing combined with mass spectrometry (MS)-based proteomics, we detected more than 100 secretory proteins in the silk cocoons. Fibroin, sericins, and protease inhibitors were found to be the most abundant proteins, along with several novel candidate silk components. We also verified the tissue and developmental stage specificity of the silk protein expression and characterized the morphology of both the silk glands and silk in T. bisselliella. Our study provides a detailed analysis of silk in the primitive moth, expands the known set of silk-specific genes in Lepidoptera, and helps to elucidate their evolutionary relationships.

• Klíčová slova
• Adhesive, Fibroin, Peptide fingerprinting, Sericin, Serine protease, Transcriptome, Zonadhesin-like,
• MeSH
• biologická evoluce * MeSH
• fibroiny metabolismus   MeSH
• hedvábí * chemie   genetika   metabolismus   MeSH
• hmyzí proteiny genetika   metabolismus   MeSH
• inhibitory proteas metabolismus   MeSH
• larva genetika   metabolismus   fyziologie   MeSH
• můry * genetika   metabolismus   fyziologie   MeSH
• proteomika metody   MeSH
• sericiny metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• fibroiny MeSH
• hedvábí * MeSH
• hmyzí proteiny MeSH
• inhibitory proteas MeSH
• sericiny MeSH

Lepidopteran silk is a complex assembly of proteins produced by a pair of highly specialized labial glands called silk glands. Silk composition has been examined only in a handful of species. Here we report on the analysis of silk gland-specific transcriptomes from three developmental stages of the greater wax moth, Galleria mellonella, combined with proteomics, Edman microsequencing and northern blot analysis. In addition to the genes known earlier, we identified twenty seven candidate cDNAs predicted to encode secretory proteins, which may represent novel silk components. Eight were verified by proteomic analysis or microsequencing, and several others were confirmed by similarity with known silk genes and their expression patterns. Our results revealed that most candidates encode abundant secreted proteins produced by middle silk glands including ten sericins, two seroins, one or more mucins, and several sequences without apparent similarity to known proteins. We did not detect any novel PSG-specific protein, confirming that there are only three fibroin subunits. Our data not only show that the number of sericin genes in the greater wax moth is higher than in other species thus far examined, but also the total content of soluble proteins in silk is twice as high in G. mellonella than in B. mori or A. yamamai. Our data will serve as a foundation for future identification and evolutionary analysis of silk proteins in the Lepidoptera.

• Klíčová slova
• B. mori, Cocoon, Lepidoptera, Mucin, Sericin, Silk glands,
• MeSH
• fylogeneze MeSH
• glykoproteiny chemie   genetika   metabolismus   MeSH
• hedvábí genetika   metabolismus   MeSH
• hmyzí proteiny chemie   genetika   metabolismus   MeSH
• larva genetika   růst a vývoj   metabolismus   MeSH
• muciny chemie   genetika   metabolismus   MeSH
• můry genetika   růst a vývoj   metabolismus   MeSH
• proteom * MeSH
• sekvence aminokyselin MeSH
• sekvence nukleotidů MeSH
• sekvenční seřazení MeSH
• sericiny chemie   genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• glykoproteiny MeSH
• hedvábí MeSH
• hmyzí proteiny MeSH
• muciny MeSH
• proteom * MeSH
• sericiny MeSH

The silks produced by caterpillars consist of fibroin proteins that form two core filaments, and sericin proteins that seal filaments into a fiber and conglutinate fibers in the cocoon. Sericin genes are well-known in Bombyx mori (Bombycidae) but have received little attention in other insects. This paper shows that Antheraea yamamai (Saturniidae) contains five sericin genes very different from the three sericin genes of B. mori. In spite of differences, all known sericins are characterized by short exons 1 and 2 (out of 3-12 exons), expression in the middle silk gland section, presence of repeats with high contents of Ser and charged amino acid residues, and secretion as a sticky silk component soluble in hot water. The B. mori sericins represent tentative phylogenetic lineages (I) BmSer1 and orthologs in Saturniidae, (II) BmSer2, and (III) BmSer3 and related sericins of Saturniidae and of the pyralid Galleria mellonella. The lineage (IV) seems to be limited to Saturniidae. Concerted evolution of the sericin genes was apparently associated with gene amplifications as well as gene loses. Differences in the silk fiber morphology indicate that the cocktail of sericins linking the filaments and coating the fiber is modified during spinning. Silks are composite biomaterials of conserved function in spite of great diversity of their composition.

• MeSH
• fylogeneze MeSH
• hedvábí chemie   MeSH
• hmyzí proteiny chemie   genetika   metabolismus   MeSH
• můry metabolismus   MeSH
• sekvence aminokyselin MeSH
• sekvenční homologie aminokyselin MeSH
• sericiny chemie   genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• hedvábí MeSH
• hmyzí proteiny MeSH
• sericiny MeSH

A reliable, cryoprotective, xeno-free medium suitable for different cell types is highly desirable in regenerative medicine. There is danger of infection or allergic reaction with the use of fetal bovine serum (FBS), making it problematic for medical applications. The aim of the present study was to develop an FBS-free cryoprotective medium for human mesenchymal stromal cells (hMSCs; primary cells) and immortalized human osteoblasts (SAOS-2 cell line). Furthermore, we endeavored to eliminate or reduce the presence of dimethyl sulfoxide (DMSO) in the medium. Sericin, a sticky protein derived from the silkworm cocoon, was investigated as a substitute for FBS and DMSO in the freezing medium. Cell viability (24 hours after thawing, both hMSC and SAOS-2) and colony-forming ability (2 weeks after thawing, only for hMSCs) were both determined. The FBS-free medium with 1% sericin in 10% DMSO was found to be a suitable freezing medium for primary hMSCs, in contrast to immortalized human osteoblasts. Surprisingly, the storage of hMSCs in a cultivation medium with only 10% DMSO also provided satisfactory results. Any drop in DMSO concentration led to significantly worse survival of cells, with little improvement in hMSC survival in the presence of sericin. Thus, sericin may substitute for FBS in the freezing medium for primary hMSCs, but cannot substitute for DMSO.

• MeSH
• dimethylsulfoxid chemie   farmakologie   MeSH
• kryoprezervace metody   MeSH
• kryoprotektivní látky chemie   farmakologie   MeSH
• kultivační média bez séra chemie   farmakologie   MeSH
• lidé MeSH
• mezenchymální kmenové buňky cytologie   MeSH
• osteoblasty cytologie   MeSH
• sericiny chemie   farmakologie   MeSH
• sérum chemie   MeSH
• skot MeSH
• viabilita buněk účinky léků   MeSH
• zmrazování MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• práce podpořená grantem MeSH
• Názvy látek
• dimethylsulfoxid MeSH
• kryoprotektivní látky MeSH
• kultivační média bez séra MeSH
• sericiny MeSH

Sericins are hydrophilic structural proteins produced by caterpillars in the middle section of silk glands and layered over fibroin proteins secreted in the posterior section. In the process of spinning, fibroins form strong solid filaments, while sericins seal the pair of filaments into a single fiber and glue the fiber into a cocoon. Galleria mellonella and the previously examined Bombyx mori harbor three sericin genes that encode proteins containing long repetitive regions. Galleria sericin genes are similar to each other and the protein repeats are built from short and extremely serine-rich motifs, while Bombyx sericin genes are diversified and encode proteins with long and complex repeats. Developmental changes in sericin properties are controlled at the level of gene expression and splicing. In Galleria , MG-1 sericin is produced throughout larval life until the wandering stage, while the production of MG-2 and MG-3 reaches a peak during cocoon spinning.

• MeSH
• druhová specificita MeSH
• hedvábí chemie   MeSH
• konformace proteinů MeSH
• molekulární sekvence - údaje MeSH
• můry chemie   MeSH
• sekvence aminokyselin MeSH
• sekvence nukleotidů MeSH
• sekvenční homologie nukleových kyselin MeSH
• sericiny chemie   genetika   MeSH
• sestřih RNA MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• hedvábí MeSH
• sericiny MeSH

Sericins are soluble silk components encoded in Bombyx mori by three genes, of which Ser1 and Ser3 have been characterized. The Ser1 and Ser3 proteins were shown to appear later in the last larval instar as the major sericins of cocoon silk. These proteins are, however, virtually absent in the highly adhesive silk spun prior to cocoon spinning, when the larvae construct a loose scaffold for cocoon attachment. We show here that the silk-gland lumen of the feeding last instar larvae contains two abundant adhesive proteins of 230 kDa and 120 kDa that were identified as products of the Ser2 gene. We also describe the sequence, exon-intron structure, alternative splicing and deduced translation products of this gene in the Daizo p50 strain of B. mori. Two mRNAs of 5.7 and 3.1 kb are generated by alternative splicing of the largest exon. The predicted mature proteins contain 1740 and 882 amino acid residues. The repetitive amino acid sequence encoded by exons 9a and 9b is apparently responsible for the adhesiveness of Ser2 products. It has a similar periodic arrangement of motifs containing lysine and proline as a highly adhesive protein of the mussel Mytilus edulis.

• MeSH
• bourec enzymologie   MeSH
• klonování DNA MeSH
• molekulární sekvence - údaje MeSH
• regulace genové exprese fyziologie   MeSH
• sekvence aminokyselin MeSH
• sericiny genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• sericiny MeSH