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Bacterial symbiont and salivary peptide evolution in the context of leech phylogeny

Published online by Cambridge University Press:  10 May 2011

MARK E. SIDDALL ,
GI-SIK MIN ,
FRANK M. FONTANELLA ,
ANNA J. PHILLIPS  and
SARA C. WATSON
MARK E. SIDDALL*
Affiliation:
Sackler Institute of Comparative Genomics & Division of Invertebrate Zoology, American Museum of Natural History, New York, NY, USA
GI-SIK MIN
Affiliation:
Department of Biological Sciences, Inha University, Yonghyun-dong, Nam-Gu, Incheon 402-751, Korea
FRANK M. FONTANELLA
Affiliation:
Department of Biology, Brigham Young University, Provo, UT 84602, USA
ANNA J. PHILLIPS
Affiliation:
Sackler Institute of Comparative Genomics & Division of Invertebrate Zoology, American Museum of Natural History, New York, NY, USA Department of Biology, The Graduate Center, The City University of New York, New York, NY, USA
SARA C. WATSON
Affiliation:
Sackler Institute of Comparative Genomics & Division of Invertebrate Zoology, American Museum of Natural History, New York, NY, USA
*
*Corresponding author: Mark E Siddall. E-mail: [email protected]
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Summary

The evolutionary history of leeches is employed as a general framework for understanding more than merely the systematics of this charismatic group of annelid worms, and serves as a basis for understanding blood-feeding related correlates ranging from the specifics of gut-associated bacterial symbionts to salivary anticoagulant peptides. A variety of medicinal leech families were examined for intraluminal crop bacterial symbionts. Species of Aeromonas and Bacteroidetes were characterized with DNA gyrase B and 16S rDNA. Bacteroidetes isolates were found to be much more phylogenetically diverse and suggested stronger evidence of phylogenetic correlation than the gammaproteobacteria. Patterns that look like co-speciation with limited taxon sampling do not in the full context of phylogeny. Bioactive compounds that are expressed as gene products, like those in leech salivary glands, have ‘passed the test’ of evolutionary selection. We produced and bioinformatically mined salivary gland EST libraries across medicinal leech lineages to experimentally and statistically evaluate whether evolutionary selection on peptides can identify structure-function activities of known therapeutically relevant bioactive compounds like antithrombin, hirudin and antistasin. The combined information content of a well corroborated leech phylogeny and broad taxonomic coverage of expressed proteins leads to a rich understanding of evolution and function in leech history.

Keywords

Leechesphylogenymicrobiologyprotein evolution
Type
Research Article
Information
Parasitology , Volume 138 , Special Issue 13: Systematics as a cornerstone of parasitology , November 2011 , pp. 1815 - 1827
Copyright
Copyright © Cambridge University Press 2011

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References

REFERENCES

Apakupakul, K., Siddall, M. E. and Burreson, E. M. (1999). Higher level relationships of leeches (Annelida: Clitellata: Euhirudinea) based on morphology and gene sequences. Molecular Phylogenetics and Evolution 12, 350–359. doi:10.1006/mpev.1999.0639.CrossRefGoogle ScholarPubMed
Bader, D. A., Roshan, U. and Stamatakis, A. (2006). Computational grand challenges in assembling the tree of life: problems and solutions. Advances in Computers 68, 127–176. doi:10.1016/S0065-2458(06)68004-2.CrossRefGoogle Scholar
Baskova, I. P. and Zavalova, L. L. (2001). Proteinase inhibitors from the medicinal leech Hirudo medicinalis. Biochemistry Moscow 66, 703–717. doi:10.1023/A:1010223325313.CrossRefGoogle ScholarPubMed
Batchelor, A. G. G., Davison, P. and Sully, L. (1984). The salvage of congested skin flaps by the application of leeches. British Journal of Plastic Surgery 37, 358–360. doi:10.1016/0007-1226(84)90079-1.CrossRefGoogle ScholarPubMed
Borda, E., Oceguera-Figueroa, A. and Siddall, M. E. (2008). On the evolution, classification and biogeography of some haemadipsoid leeches (Hirudinida: Arhynchobdellida: Hirudiniformes). Molecular Phylogenetics and Evolution 46, 142–54. doi:10.1016/j.ympev.2007.09.006.CrossRefGoogle ScholarPubMed
Borda, E. and Siddall, M. E. (2004). Arhynchobdellida (Annelida: Oligochaeta: Hirudinida): phylogenetic relationships and evolution. Molecular Phylogenetics and Evolution 30, 213–225. doi:10.1016/j.ympev.2003.09.002.CrossRefGoogle ScholarPubMed
Borda, E. and Siddall, M. E. (2011). Insights into the evolutionary history of IndoPacific bloodfeeding terrestrial leeches (Hirudinida: Arhynchobdellida: Haemadipisdae). Invertebrate Systematics. 24, 456–472. doi:10.1071/IS10013.CrossRefGoogle Scholar
Bourtzis, K. and Miller, T. A. (2006). Insect Symbiosis, Volume 2. CRC Press/Taylor and Frances, Boca Raton, FL, London.CrossRefGoogle Scholar
Brooks, D. R. (1990). Parsimony analysis in historical biogeography and coevolution: methodological and theoretical update. Systematic Biology 39, 14–30. doi:10.2307/2992205.Google Scholar
Carroll, L. (1871). Through the Looking Glass and What Alice Found There. Macmillan, London.Google Scholar
Croizat, L. (1958). Panbiogeography, Volumes 1, 2a, 2b. Published by author. Caracas, Venezuela.Google Scholar
Derganc, M. and Zdravic, F. (1960). Venous congestion of flaps treated by application of leeches. British Journal of Plastic Surgery 13, 187–192.CrossRefGoogle ScholarPubMed
Dunlap, P. V., Ast, J. C., Kimura, S., Fukui, A., Yoshino, T. and Endo, H. (2007). Phylogenetic analysis of host-symbiont specificity and codivergence in bioluminescent symbioses. Cladistics 23, 507–532. doi:10.1111/j.1096-0031.2007.00157.x.CrossRefGoogle Scholar
Faria, F., Junqueira-de-Azevedo Ide, L., Ho, P. L., Sampaio, M. U. and Chudzinski-Tavassi, A. M. (2005). Gene expression in the salivary complexes from Haementeria depressa leech through the generation of expressed sequence tags. Gene 349, 173–185. doi:10.1016/j.gene.2004. 12.022.CrossRefGoogle ScholarPubMed
Farris, J. S., Albert, V. A., Källersjö, M., Lipscomb, D. and Kluge, A. G. (1996). Parsimony jackknifing outperforms neighbor-joining. Cladistics 12, 99–124. doi:10.1111/j.1096-0031.1996.tb00196.x.Google ScholarPubMed
Giribet, G. (2008). Assembling the lophotrochozoan (=spiralian) tree of life. Philosophical Transactions of the Royal Society B 363, 1513–1522. doi:10.1098/rstb.2007.2241.CrossRefGoogle ScholarPubMed
Goloboff, P. A., Farris, J. S. and Nixon, K. C. (2008). TNT, a free program for phylogenetic analysis. Cladistics 24, 774–786. doi:10.1111/j.1096-0031.2008.00217.x.CrossRefGoogle Scholar
Graf, J. (1999). Symbiosis of Aeromonas veronii Biovar sobria and Hirudo medicinalis, the medicinal leech: a novel model for digestive tract associations. Infection and Immunity 67, 1–7.CrossRefGoogle ScholarPubMed
Graf, J. (2000). Symbiosis of Aeromonas and Hirudo medicinalis, the medicinal leech. American Society for Microbiology News 66, 147–153.Google Scholar
Graf, J. (2002). The effect of symbionts on the physiology of Hirudo medicinalis, the medicinal leech. Invertebrate Reproduction and Development 41, 269–275.CrossRefGoogle Scholar
Greinacher, A., Völpel, H., Janssens, U., Hach-Wunderle, V., Kemkes-Matthes, B., Eichler, P., Mueller-Velten, H. G. and Pötzsch, B. (1999). Recombinant hirudin (Lepirudin) provides safe and effective anticoagulation in patients with heparin-induced thrombocytopenia. Circulation 99, 73–80.CrossRefGoogle ScholarPubMed
Greinacher, A. and Warkentin, T. E. (2008). The direct thrombin inhibitor hirudin. Thrombosis and Haemostasis 99, 819–29.Google ScholarPubMed
Haas, G. (1924). Versuche der Blutauswaschung am Lebenden mit Hilfe der Dialyse. Wiener Klinische Wochenschrift 4, 13–14. doi:10.1007/BF01745400.CrossRefGoogle Scholar
Hackett, S. J., Kimball, R. T., Reddy, S., Bowie, R. C. K., Braun, E. L., Braun, M. J., Chojnowski, J. L., Cox, W. A., Han, K.-L., Harshman, J., Huddleston, C. J., Marks, B. D., Miglia, K. J., Moore, W. S., Sheldon, F. H., Steadman, D. W., Witt, C. C., and Yuri, T. (2008). A phylogenetic study of birds reveals their evolutionary history. Science 230, 1763–1768. doi:10.1126/science.1157704CrossRefGoogle Scholar
Hittinger, C. T., Johnston, M., Tossberg, J. T. and Rokas, A. (2010). Leveraging skewed transcript abundance by RNA-Seq to increase the genomic depth of the tree of life. Proceedings of the National Academy of Sciences, USA 107, 1476–1481. doi: 10.1073/pnas.0910449107.CrossRefGoogle ScholarPubMed
Jackson, W. A. (2001). A short guide to humoral medicine. TRENDS in Pharmacological Sciences 22, 487–489.CrossRefGoogle Scholar
Keading, A. J., Ast, J. C., Pearce, M. M., Urbanczyk, H., Kimura, S., Endo, H., Nakamura, M. and Dunlap, P. V. (2007). Phylogenetic diversity and cosymbiosis in the bioluminescent symbioses of “Photobacterium mandapamensis”. Applied and Environmental Microbiology 73, 3173–3182. doi:10.1128/AEM.02212-06.CrossRefGoogle Scholar
Kiskuchi, Y. and Fukatsu, T. (2002). Endosymbiotic bacteria in the esophageal organ of glossiphoniid leeches. Applied and Environmental Microbiology 68, 4637–4641. doi:10.1128/AEM.68.9.4637-4641.2002.CrossRefGoogle Scholar
Kikuchi, Y. and Graf, J. (2007). Spatial and temporal population dynamics of a naturally occurring two-species microbial community inside the digestive tract of the medicinal leech. Applied and Environmental Microbiology 73, 1984–1991. doi:10.1128/AEM.01833-06.CrossRefGoogle ScholarPubMed
Kimbell, J. R. and McFall-Ngai, M. J. (2003). The squid-Vibrio symbioses: from demes to genes. Integrative and Comparative Biology 43, 254–260. doi: 10.1093/icb/43.2.254.CrossRefGoogle ScholarPubMed
Kimbell, J. R., McFall-Ngai, M. J. and Roderick, G. K. (2002). Two genetically distinct populations of bobtail squid, Euprymna scolopes, exist on the island of Oahu. Pacific Science 56, 347–355. http://hdl.handle.net/10125/2570.CrossRefGoogle Scholar
Kosakovsky Pond, S. L., Frost, S. D. W. and Muse., S. V. (2005). HyPhy: hypothesis testing using phylogenies. Bioinformatics 21, 676–679. doi:10.1093/bioinformatics/bti079.CrossRefGoogle Scholar
Kosiol, C., Vinar, T., da Fonseca, R. R., Hubisz, M. J., Bustamante, C. D., Nielsen, R. and Siepel, A. (2008). Patterns of positive selection in six mammalian genomes. PLoS Genetics 4, e1000144. doi:10.1371/journal.pgen.1000144.CrossRefGoogle ScholarPubMed
Kristensen, D. M., Kannan, L., Coleman, M. K., Wolf, Y. I., Sorokin, A., Koonin, E. V. and Mushegian, A. (2010). A low-polynomial algorithm for assembling clusters of orthologous groups from intergenomic symmetric best matches. Bioinformatics 26, 1481–1487.CrossRefGoogle ScholarPubMed
Kvist, S., Montanari, S. A., Yi, H., Fuks, B. and Siddall, M. E. (2011). Teaching Biodiversity & Evolutionary Biology in a North American Marine Coastal Environment. The American Biology Teacher 73, 72–77. doi:10.1525/abt.2011.73.2.4.CrossRefGoogle Scholar
Lakatos, I. (1971). History of science and its rational reconstruction. Proceedings of the Biennial Meeting of the Philosophy of Science Association 1970, 91–136 http://www.jstor.org/stable/495757.CrossRefGoogle Scholar
Lapatto, R., Krengel, U., Schreuder, H. A., Arkema, A., de Boer, B., Kalk, K. H., Hol, W. G., Grootenhuis, P. D., Mulders, J. W., Dijkema, R., Theunissen, H. J. and Dijkstra, B. W. (1997). X-ray structure of antistasin at 1·9 A resolution and its modelled complex with blood coagulation factor Xa. EMBO Journal 16, 5151–5161. doi:10.1093/emboj/16.17.5151.CrossRefGoogle ScholarPubMed
Laufer, A. S., Siddall, M. E. and Graf, J. (2008). Characterization of the digestive-tract microbiota of Hirudo orientalis, a European medicinal leech. Applied and Environmental Microbiology 74, 6151–6154. doi:10.1128/AEM.00795-08.CrossRefGoogle ScholarPubMed
Mason, T. A., McIlroy, P. J. and Shain, D. H. (2004). A cysteine-rich protein in the Theromyzon (Annelida: Hirudinea) cocoon membrane. Federation of European Biochemical Societies Letters 561, 167–172. doi:10.1016/S0014-5793(04)00167-X.CrossRefGoogle ScholarPubMed
Markwardt, F. (1992). Hirudin: The promising antithrombotic. Cardiovascular Drug Reviews 10, 211–232. doi:10.1111/j.1527-3466.1992.tb00247.x.CrossRefGoogle Scholar
McLaughlin, D. J., Hibbett, D. S., Lutzoni, F., Spatafora’, J. W. and Vilgalys, R. (2009). The search for the fungal tree of life. Trends in Microbiology 17, 488–497. doi:10.1016/j.tim.2009.08.001.CrossRefGoogle ScholarPubMed
Min, G-S., Sarkar, I. N., and Siddall, M. E. (2010). Salivary transcriptome of the North American medicinal leech, Macrobdella decora. Journal of Parasitology 96, 1211–1221. doi:10.1645/GE-2496.1.CrossRefGoogle ScholarPubMed
Morabia, A. (1996). P. C. A. Louis and the birth of clinical epidemiology. Journal of Clinical Epidemiology 49, 1327–1333. doi:10.1016/S0895-4356(96)00294-6.CrossRefGoogle Scholar
Moran, N. A. (2001). The coevolution of bacterial endosymbionts and phloem-feeding insects. Annals of the Missouri Botanical Garden 88, 35–44. http://www.jstor.org/stable/2666130.CrossRefGoogle Scholar
Munro, R., Siddall, M., Desser, S. S., and Sawyer, R. T. (1992). The leech as a tool for studying comparative haematology. Comparative Haematology International 2, 75–78. doi:10.1007/BF00186263.CrossRefGoogle Scholar
Nishiguchi, M. K. (2002). Host-symbiont recognition in the environmentally transmitted sepiolid squid-Vibrio mutualism. Microbial Ecology 44, 10–18. doi:10.1007/BF03036870.CrossRefGoogle ScholarPubMed
Nishiguchi, M. K., Lopez, J. E. and Boletzky, S. V. (2004). Enlightenment of old ideas from new investigations: more questions regarding the evolution of bacteriogenic light organs in squids. Evolution and Development 6, 41–49. doi:10.1111/j.1525-142X.2004.04009.x.CrossRefGoogle ScholarPubMed
Nishiguchi, M. K., Ruby, E. G. and McTall-Ngai, M. J. (1998). Competitive dominance among strains of luminous bacteria provides an unusual form of evidence for parallel evolution in sepiolid squid-vibrio symbioses. Applied and Environmental Microbiology 64, 3209–3213.CrossRefGoogle ScholarPubMed
Nixon, K. C. (1999). The parsimony ratchet, a new method for rapid parsimony analysis. Cladistics 15, 407–414. doi:10.1111/j.1096-0031.1999.tb00277.x.CrossRefGoogle ScholarPubMed
Nogge, G. (1981). Significance of symbionts for the maintenance of an optional nutritional state for successful reproduction in haematophagous arthropods. Parasitology 82, 101–104.Google Scholar
Nylander, J. A. A., Olsson, U., Alström, P. and Sanmartín, I. (2008). Accounting for phylogenetic uncertainty in biogeography: a Bayesian approach to Dispersal-vicariance Analysis of the thrushes (Aves: Turdus). Systematic Biology 57, 257–268. doi: 10.1080/10635150802044003.CrossRefGoogle ScholarPubMed
Oceguera-Figueroa, A., Phillips, A. J., Pacheco-Chaves, B., Reeves, W. K. and Siddall, M. E. (2011). Phylogeny of macrophagous leeches (Hirudinea, Clitellata) based on molecular data and evaluation of the barcoding locus. Zoologica Scripta 40, 194–203. doi:10.1111/j.14636-409.2010.00465.x.CrossRefGoogle Scholar
Page, R. D. M. (1990). Component analysis: a valiant failure? Cladistics 6, 119–136. doi:10.1111/j.1096-0031.1990.tb00532.x.CrossRefGoogle ScholarPubMed
Perkins, S. L., Budinoff, R. B. and Siddall, M. E. (2005). New gammaproteobacteria associated with blood-feeding leeches and a broad phylogenetic analysis of leech endosymbionts. Applied and Environmental Microbiology 71, 5219–5224. doi:10.1128/AEM.71.9.5219-5224.2005.CrossRefGoogle Scholar
Phillips, A. J., Arauco-Brown, R., Oceguera-Figueroa, A., Gomez, G. P., Beltran, M., Lai, Y.-T. and Siddall, M. E. (2010). Tyrannobdella rex n. gen. n. sp. and the evolutionary origins of mucosal leech infestations. PLoS ONE 5, e10057. doi:10.1371/journal.pone.0010057.CrossRefGoogle Scholar
Phillips, A. J. and Siddall, M. E. (2005). Phylogeny of the New World medicinal leech family Macrobdellidae (Oligochaeta: Hirudinida: Arhynchobdellida). Zoologica Scripta 34, 559–564. doi:10.1111/j.1463-6409.2005.00210.x.CrossRefGoogle Scholar
Phillips, A. J. and Siddall, M. E. (2009). Poly-paraphyly of Hirudinidae: Many lineages of medicinal leeches. BMC Evolutionary Biology 9, 246–256. doi:10.1186/1471-2148-9-246.CrossRefGoogle ScholarPubMed
Pond, S. L. K. and Frost, S. D. W. (2005). Datamonkey: rapid detection of selective pressure on individual sites of codon alignments. Bioinformatics 21, 2531–2533. doi: 10.1093/bioinformatics/bti320.CrossRefGoogle ScholarPubMed
Poon, A. F. Y., Lewis, F. I., Kosakovsky Pond, S. L. and Frost, S. D. W. (2007). An evolutionary-network model reveals stratified interactions in the V3 loop of the HIV-1 envelope. PLoS Computational Biology 3, e231. doi:10.1371/journal.pcbi.0030231.CrossRefGoogle ScholarPubMed
Rados, C. (2004). Beyond bloodletting: FDA gives leeches a medical makeover. FDA Consumer 38, 9.Google ScholarPubMed
Ree, R. H. and Smith, S. A. (2008). Maximum likelihood inference of geographic range evolution by dispersal, local extinction, and cladogenesis. Systematic Biology 57, 4–14. doi: 10.1080/10635150701883881.CrossRefGoogle ScholarPubMed
Rio, R. V. M. (2008). Tsetse fly and medicinal leech symbioses: providing insights into microbial species interactions within gastrointestinal systems. Vie Milieu 58, 153–163.Google Scholar
Rio, R. V. M., Anderegg, M. and Graf, J. (2007). Characterization of a catalase gene from Aeromonas veronii, the digestive-tract symbiont of the medicinal leech. Microbiology 153, 1897–1906. doi:10.1099/mic.0.2006/003020-0CrossRefGoogle ScholarPubMed
Rio, R. V. M., Maltz, M., McCormick, B., Reiss, A. and Graf, J. (2009). Symbiont succession during embryonic development of the European medicinal leech, Hirudo verbana. Applied and Environmental Microbiology 75, 6890–6895. doi:10.1128/AEM.01129-09.CrossRefGoogle ScholarPubMed
Rocha, E. P., Smith, J. M., Hurst, L. D., Holden, M. T., Cooper, J. E., Smith, N. H. and Feil, E. J. (2005). Comparisons of dN/dS are time dependent for closely related bacterial genomes. Journal of Theoretical Biology 239, 226–35.CrossRefGoogle ScholarPubMed
Ronquist, F. (1997). Dispersal-vicariance analysis: a new approach to the quantification of historical biogeography. Systematic Biology 46, 195–203. doi: 10.1093/sysbio/46.1.195.CrossRefGoogle Scholar
Salzet, M. (2001). Anticoagulants and inhibitors of platelet aggregation derived from leeches. Federation of European Biochemical Societies Letters 429, 187–192. doi:10.1016/S0014-5793(01)02212-8.CrossRefGoogle Scholar
Sawyer, R. T. (1999). The trade in medicinal leeches in the southern Indian Ocean in the nineteenth century. Medical History 43, 241–245.CrossRefGoogle ScholarPubMed
Scheffler, K., Martin, D. P. and Seoighe, C. (2006). Robust inference of positive selection from recombining coding sequences. Bioinformatics 22, 2493–2499. doi: 10.1093/bioinformatics/btl427.CrossRefGoogle ScholarPubMed
Siddall, M. E. (2002). Phylogeny and revision of the leech family Erpobdellidae (Hirudinida: Oligochaeta). Invertebrate Systematics 16, 1–6. doi:10.1071/IT01011.CrossRefGoogle Scholar
Siddall, M. E., Apakupakul, K., Burreson, E. M., Coates, K. A., Erséus, C., Gelder, S. R., Källersjö, M. and Trapido-Rosenthal, H. (2001). Validating Livanow: Molecular data agree that leeches, Branchiobdellidans and Acanthobdella peledina form a monophyletic group of Oligochaetes. Molecular Phylogenetics and Evolution 21, 346–351. doi:10.1006/mpev.2001.1021.CrossRefGoogle Scholar
Siddall, M. E., Budinoff, R. B., and Borda, E. (2005). Phylogenetic evaluation of systematics and biogeography of the leech family Glossphoniidae. Invertebrate Systematics 19, 105–112. doi:10.1071/IS04034.CrossRefGoogle Scholar
Siddall, M. E. and Burreson, E. M. (1998). Phylogeny of leeches (Hirudinea) based on mitochondrial cytochrome c Oxidase Subunit I. Molecular Phylogenetics and Evolution 9, 156–162. doi:10.1006/mpev.1997.0455.CrossRefGoogle ScholarPubMed
Siddall, M. E. and Burreson, E. M. (1995). Phylogeny of the Euhirudinea: Independent evolution of blood feeding by leeches? Canadian Journal of Zoology 73, 1048–1064. doi:10.1139/z95-125.CrossRefGoogle Scholar
Siddall, M. E., Perkins, S. L. and Desser, S. S. (2004). Leech mycetome endosymbionts are a new lineage of alphaproteobacteria related to the Rhizobiaceae. Molecular Phylogenetics and Evolution 30, 178–186. doi:10.1016/S1055-7903(03)00184-2.CrossRefGoogle Scholar
Siddall, M. E., Trontelj, P., Utevsky, S. Y., Nkamany, M. and Macdonald, K. S. (2007 a). Diverse molecular data demonstrate that commercially available medicinal leeches are not Hirudo medicinalis. Proceedings of the Royal Society B 274, 1481–1487. doi: 10.1098/rspb.2007.0248.CrossRefGoogle Scholar
Siddall, M. E., Worthen, P. L., Johnson, M. and Graf, J. (2007 b). Novel role for Aeromonas jandaei as a digestive tract symbiont of the North American medicinal leech. Applied and Environmental Microbiology 73, 655–658. doi: 10.1128/AEM.01282-06.CrossRefGoogle ScholarPubMed
Silver, A., Rabinowitz, N. M., Küffer, S. and Graf, J. (2007). Identification of Aeromonas veronii genes required for colonization of the medicinal leech, Hirudo verbana. Journal of Bacteriology 189, 6763–6772. doi:10.1128/JB.00685-07.CrossRefGoogle ScholarPubMed
Soto, W., Gutierrez, J., Remmenga, M. D. and Nishiguchi, M. K. (2009). Salinity and temperature effects of physiological responses of Vibrio fischeri from diverse ecological niches. Microbial Ecology 57, 140–150. doi:10.1007/s00248-008-9412-9.CrossRefGoogle ScholarPubMed
Utevsky, S. Y. and Trontelj, P. (2004). Phylogenetic relationships of fish leeches (Hirudinea, Piscicolidae) based on mitochondrial DNA sequences and morphological data. Zoologica Scripta 33, 375–385. doi:10.1111/j.0300-3256.2004.00156.x.CrossRefGoogle Scholar
Warren, R. L., Sutton, G. G., Jones, S. M. J. and Holt, R. A. (2007). Assembling millions of short DNA sequences using SSAKE. Bioinformatics 23, 500–501. doi:10.1093/bioinformatics/btl629.CrossRefGoogle ScholarPubMed
Whitaker, I. S., Kamya, C., Azzopardi, E. A., Graf, J., Kon, M. and Lineaweaver, W. C. (2009). Preventing infective complications following leech therapy: Is practice keeping pace with current research? Microsurgery 29, 619–625. doi:10.1002/micr.20666.CrossRefGoogle ScholarPubMed
Williams, J. I. and Burreson, E. M. (2006). Phylogeny of the fish leeches (Oligochaeta, Hirudinida, Piscicolidae) based on nuclear and mitochondrial genes and morphology. Zoologica Scripta 35, 627–639. doi:10.1111/j.1463-6409.2006.00246.x.CrossRefGoogle Scholar
Worthen, P. L., Gode, C. J. and Graf, J. (2006). Culture-independent characterization of the digestive-tract microbiota of the medicinal leech reveals a tripartite symbiosis. Applied and Environmental Microbiology 72, 4775–4781. doi:10.1128/AEM.00356-06.CrossRefGoogle ScholarPubMed