Leech Salivary Proteome and Transcriptome: 434 Deduced Protein Sequences

Integrated proteomics and transcriptomics of leech salivary glands (Liu et al. 2019)

Genomics & ProteomicsLiu Z, Tong X, Su Y, et al. (2019)— Journal of ProteomicsDOI →

Why This Matters for Hirudotherapy

Shows that combining proteomics with transcriptomics can reveal low-abundance salivary proteins, and that treatment efficiency may differ between leech species. For the medicinal leech itself, see Babenko et al. 2020: 189 salivary proteins identified in Hirudo medicinalis.

Investigational / Research Priority

Basic science research. This review covers proteomics and transcriptomics findings with no direct clinical application at this stage.

Last Updated: September 25, 2026Reviewed by: ASH Editorial Board

Salivary proteomicsDiscovery science

What the study did

Liu et al. (2019) performed an in-depth proteomic analysis of leech salivary glands and combined it with transcriptome data, deducing 434 full-length protein sequences. After integrating both datasets, 44 proteins and 221 transcripts of bioactive molecules were involved in leech sucking pathways. The abstract does not name the leech species, so these figures should not be read as the salivary proteome of Hirudo medicinalis.[R1]

What is known for the medicinal leech

For Hirudo medicinalis, the most direct count comes from Babenko et al. (2020): mass spectrometry identified 189 proteins in its salivary cell secretion, 344 in H. verbana and 86 in H. orientalis. No published source gives a combined total of “440+” salivary proteins.

Methodology

The study combined two complementary omics approaches:

Proteomics (protein-level)

A high-throughput proteomic analysis of the salivary glands, aimed at proteins present in the secretion at low concentrations.

Transcriptomics (RNA-level)

Salivary-gland transcriptome data, integrated with the proteome to deduce full-length protein sequences, plus a gene-expression analysis of the bioactive genes.

[R1]

Key numbers

434

Full-length protein sequences deduced

Bioactive proteins in feeding pathways

221

Bioactive transcripts in feeding pathways

What it means for hirudotherapy

The authors conclude that treatment efficiency can differ depending on the leech species, and that combining high-throughput proteomics with transcriptomics is an effective way to profile proteins present only at low concentrations in the secretion.[R1]

They present the dataset as a foundation for discovering new pharmacological agents or targets in leech therapy. For the medicinal leech itself, the corresponding data come from the Hirudo genome and salivary-transcriptome studies of Kvist et al. (2020) and Babenko et al. (2020).[R2][R3]

Genome data for the medicinal leech

Kvist et al. (2020) presented what they describe as the first draft genome of Hirudo medicinalis and found 15 known anticoagulation factors and 17 other antihemostasis-linked proteins in it. Babenko et al. (2020), published in April 2020, had reported an earlier, independent genome draft of H. medicinalis together with salivary-cell transcriptomes of three Hirudo species, verified by proteomics.

References

[R1]
In-depth profiles of bioactive large molecules in saliva secretions of leeches determined by combining salivary gland proteome and transcriptome data
Journal of Proteomics(2019)https://doi.org/10.1016/j.jprot.2019.03.009
Primary source (Liu et al., PMID 30880165).
[R2]
Draft genome of the European medicinal leech Hirudo medicinalis (Annelida, Clitellata, Hirudiniformes) with emphasis on anticoagulants
Scientific Reports(2020)https://doi.org/10.1038/s41598-020-66749-5
Kvist et al. 2020, draft genome of H. medicinalis.
[R3]
Draft genome sequences of Hirudo medicinalis and salivary transcriptome of three closely related medicinal leeches
BMC Genomics(2020)https://doi.org/10.1186/s12864-020-6748-0
Babenko et al. 2020 (PMID 32349672): 189, 86 and 344 proteins identified in the salivary cell secretion of H. medicinalis, H. orientalis and H. verbana.

← All research articles