De novo assembly and characterisation of the transcriptome of the Beringian pseudoscorpion

Pseudoscorpions are microarthropods that are distributed from the equator to beyond the Arctic circle. Wyochernes asiaticus (Arachnida: Pseudoscorpiones: Chernetidae) is the northernmost species of pseudoscorpion and is broadly distributed in Beringia, an Arctic and sub-Arctic region that remained unglaciated during the last glacial maximum. Wyochernes asiaticus is anoxia tolerant and has moderate cold tolerance, but nothing is known about the molecular basis of their survival in Canadian polar environments. We de novo assembled and characterised the transcriptome of W. asiaticus collected from the Yukon Territory in northwestern Canada. We assembled an approximately 62.6-million base-pair transcriptome with a mean contig length of 1277, which was 76% complete, according to a benchmark universal single copy orthologue (BUSCO) analysis. We identified 1100 transcripts encoding proteins associated with stress tolerance in these pseudoscorpions, including heat shock proteins, antioxidants, ubiquitination and proteosomal proteins, and sirtuins. We also identified transcripts encoding putative venom proteins. We highlight eight transcripts with high sequence similarity to sequences of venom proteins (ctenitoxins and agatoxins) described from other pseudoscorpions. Our study yields the first transcriptome of a Beringian arthropod, providing important sequence information that will allow future investigation of how W. asiaticus survives in Canadian polar environments.