Draft genome sequences of Hirudo medicinalis and salivary transcriptome of three closely related medicinal leeches

Abstract

Background Salivary cell secretion (SCS) plays a critical role in blood feeding by medicinal leeches, making them of use for certain medical purposes even today. Results We annotated the Hirudo medicinalis genome and performed RNA-seq on salivary cells isolated from three closely related leech species, H. medicinalis, Hirudo orientalis, and Hirudo verbana. Differential expression analysis verified by proteomics identified salivary cell-specific gene expression, many of which encode previously unknown salivary components. However, the genes encoding known anticoagulants have been found to be expressed not only in salivary cells. The function-related analysis of the unique salivary cell genes enabled an update of the concept of interactions between salivary proteins and components of haemostasis. Conclusions Here we report a genome draft of Hirudo medicinalis and describe identification of novel salivary proteins and new homologs of genes encoding known anticoagulants in transcriptomes of three medicinal leech species. Our data provide new insights in genetics of blood-feeding lifestyle in leeches.

The Genome of Medicinal Leech (Whitmania pigra) and comparative genomic study for Exploration of Bioactive Ingredients

“…H. robusta is a leech of the family glossiphoniidae, which is very far from the family hirudinidae [22]. The genome of H. medicinalis in the family hirudinidae was just published during the review period of this study [8,9]. In this study, we reported the genome of W. pigra, another medicinal leech in the family hirudinidae.…”

“…Its early development has been studied extensively. For another important family hirudinidae, the genome of H. medicinalis has just been published during the review period of this study [8,9]. The family hirudinidae includes medicinal leeches which have been widely utilized in medical procedures for thousands of years.…”

The Hirudo Medicinalis Microbiome Is a Source of New Antimicrobial Peptides

“…The contigs of the H. medicinalis microbiome were generated during a previous study involving the H. medicinalis genome analysis due to the binning procedure [ 16 ]. De novo annotation of the metagenome H. medicinalis allowed us to generate a database of proteins that can serve as a source of AMPs.…”

“…The metagenome contigs were retrieved previously in the process of H. medicinalis genome annotation [ 16 ]. Bacterial contig groups were annotated using PROKKA (University of Melbourne, Melbourne, Australia) and GhostKOALA (Kyoto University Bioinformatics Center, Kyoto, Japan) software [ 49 , 50 ].…”

“…Microbiome analysis of H. medicinalis will provide a better understanding of the mechanism underlying medicinal leech and symbiotic microbe interactions. Recently, we annotated the H. medicinalis genome and described the identification of novel anticoagulant proteins [ 16 ]. Moreover, we developed an in silico screening method that allowed the identification of new AMPs with a low haemolytic and toxic activity.…”