American Society of Hirudotherapy

Spatial regulation dominates gene function in the ganglia chain

Basic science / transcriptomics published in Bioinformatics (2013)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Preclinical (animal)Genomics & ProteomicsHibsh D et al. · Bioinformatics (Oxford, England), 2013

Abstract

MOTIVATION: To understand the molecular mechanisms of neurons, it is imperative to identify genomic dissimilarities within the heterogeneity of the neural system. This is especially true for neuronal disorders in which spatial considerations are of critical nature. For this purpose, Hirudo medicinalis provides here an ideal system in which we are able to follow gene expression along the central nervous system, to affiliate location with gene behavior. RESULTS: In all, 221.1 million high-quality short reads were sequenced on the Illumina Hiseq2000 platform at the single ganglion level. Thereafter, a de novo assembly was performed using two state-of-the-art assemblers, Trinity and Trans-ABySS, to reconstruct a comprehensive de novo transcriptome. Classification of Trinity and Trans-ABySS transcripts produced a non-redundant set of 76 845 and 268 355 transcripts (>200 bp), respectively. Remarkably, using Trinity, 82% of the published medicinal leech messenger RNAs was identified. For the innexin family, all of the 21 recently reported genes were identified. Spatial regulation analysis across three ganglia throughout the entire central nervous system revealed distinct patterns of gene expression. These transcriptome data were combined with expression distribution to produce a spatio-transcripto map along the ganglia chain. This study provides a resource for gene discovery and gene regulation in future studies.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeJournal ArticleResearch Support, Non-U.S. Gov't
Indexed MeSH termsAnimalsGangliaGene Expression ProfilingGene Expression RegulationGenomicsHirudo medicinalisRNA IsoformsRNA, MessengerSequence Analysis, RNATranscriptome

Summary

RNA-seq de novo transcriptome assembly of Hirudo medicinalis ganglion chain identifying 76,845 transcripts. 82% of published medicinal-leech mRNAs identified including all 21 innexin genes. Spatio-transcripto map established.

Why This Matters for Hirudotherapy

This study performed single-ganglion-level transcriptome sequencing of the Hirudo medicinalis central nervous system using the Illumina HiSeq 2000 platform, generating over 221 million high-quality reads and de novo assemblies that identified 82% of previously published medicinal leech mRNAs, including all 21 known innexin genes. Spatial regulation analysis across three ganglia revealed distinct gene expression patterns, yielding a spatio-transcriptome map along the ganglia chain. For ASH's domain, this provides a genomic resource for Hirudo medicinalis that could support future molecular studies of leech biology and bioactive secretions. Caveat: This is basic neuroscience and transcriptomics research with no direct or immediate clinical hirudotherapy application; its relevance to ASH is foundational rather than translational.

Citation

Spatial regulation dominates gene function in the ganglia chain.

Hibsh D et al. · Bioinformatics (Oxford, England), 2013

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