SUPR
Spider silk analysis
Dnr:

NAISS 2023/6-13

Type:

NAISS Medium Storage

Principal Investigator:

Johan Reimegård

Affiliation:

Uppsala universitet

Start Date:

2023-04-27

End Date:

2024-05-01

Primary Classification:

10602: Biochemistry and Molecular Biology

Allocation

Abstract

Silk fibres are nature’s toughest material and are of great interest for many industrial and medical applications. However, the production and spinning of artificial spider silk fibers are very challenging. Currently, the underlying mechanisms that regulate spider silk protein solubility and fiber formation remain poorly understood and artificially synthesized fibers are not as strong as the native material. We aim to generate artificial silk fibers with the same mechanical properties as native spider silk. Recently we were successful in expressing our recombinant silk protein with a 10-fold increase in yield after purification compared to previously published reports for recombinant silk proteins. In order to improve our understanding of the spinning process in the spider’s silk glands and make bioimimetic replicas thereof, it is necessary to understand how silk is produced in the spiders gland. One important step toward that goal is to understand what different cell types there are in the glands, which genes the different cell types express and how they are spatially distributed. To achieve this, we have done bulk RNAseq, single cell RNAseq (scRNAseq) and spatial RNA seq for the glands of the Swedish bridge spider, Larinioides sclopetarius. In parallel we have also, by using PacBio RNA and various genomic sequencing methods, created a close to complete genome with assembly and annotation carried out by NBIS assembly and annotation platform and manually curated by us. During this year with the help of the new genome and our different RNA sequence data we have finished our first step in this project to characterize the cell types and their location in the major ampullate gland. In summary; with the storage, programs and computer power we have has access to through this project we have been able to analyze 80 samples of bulk RNA, 30 000+ individual cells using scRNA and 30 000+ spatial RNA spots on the spider. By combining all this data we are now writing up a paper that shows that the spider produces it spider silk in layers and we hypothesize that this is one of the factors why the silk is so strong. We are now at a stage where we will start our second round of analysis for understanding the diversity of the different glands. This step focusses on scRNA sequencing from four other silk glands (minor, aggregate, flagelliform and tubuliform) and the correlating spatial regions in the spatial data. This step is crucial to further understand the molecular and cellular features within and between these silk glands. In parallel we are also gathering new in-situ data from the bridge spider with an even higher resolution, down to sub-cellular location, to test some of the hypothesis we have put out based on this year analysis.