Bloodfeeding is employed by many parasitic animals and requires specific innovations for efficient feeding. Some of these innovations are molecular features that are related to the inhibition of hemostasis. For example, bloodfeeding insects, bats, and leeches release proteins with anticoagulatory activity through their salivary secretions.
View Article and Find Full Text PDFLeech-derived invertebrate DNA (iDNA) has been successfully leveraged to conduct surveys of vertebrate host biodiversity across the Indo Pacific. However, this technique has been limited methodologically, typically only targeting mammalian 16S rDNA, or both 16S and vertebrate 12S rDNA for leech host determination. To improve the taxonomic richness of vertebrate host species in iDNA surveys, we re-analyze datasets from Bangladesh, Cambodia, China, and Madagascar through metabarcoding via next generation sequencing (NGS) of 12S, 16S (2 types, one designed to target mammals and the other, residual eDNA), nicotinamide adenine dinucleotide hydride dehydrogenase 2 (ND2), and cytochrome c oxidase subunit 1 (COI).
View Article and Find Full Text PDFThe European medicinal leech has been used for medicinal purposes for millennia, and continues to be used today in modern hospital settings. Its utility is granted by the extremely potent anticoagulation factors that the leech secretes into the incision wound during feeding and, although a handful of studies have targeted certain anticoagulants, the full range of anticoagulation factors expressed by this species remains unknown. Here, we present the first draft genome of the European medicinal leech, Hirudo medicinalis, and estimate that we have sequenced between 79-94% of the full genome.
View Article and Find Full Text PDFThe description of Helobdella stagnalis (Linnaeus, 1758) has emphasized the presence of a nuchal, chitinous scute located on the dorsal surface in the first third of the body as the diagnostic character for the species. Historically, identifications of species of Helobdella have relied heavily on this character and, as a result, Helobdella stagnalis has been reported from an inordinately broad geographic range, including Europe, Asia, Africa, North America, and South America. In addition to a few earlier investigations, a recent analysis showed that great genetic distances (orders of magnitude greater than previous estimations of intraspecific divergence in leeches) are present between scute-bearing specimens identified as H.
View Article and Find Full Text PDFComprising over 15 000 living species, decapods (crabs, shrimp and lobsters) are the most instantly recognizable crustaceans, representing a considerable global food source. Although decapod systematics have received much study, limitations of morphological and Sanger sequence data have yet to produce a consensus for higher-level relationships. Here, we introduce a new anchored hybrid enrichment kit for decapod phylogenetics designed from genomic and transcriptomic sequences that we used to capture new high-throughput sequence data from 94 species, including 58 of 179 extant decapod families, and 11 of 12 major lineages.
View Article and Find Full Text PDFIndirect methods for conducting faunal inventories present great promise, and genomic inventories derived from environmental sources (eDNA) are improving. Invertebrate ingested DNA (iDNA) from terrestrial leeches in the family Haemadipsidae has shown potential for surveying vertebrates and biodiversity monitoring in protected areas. Here we present an initial, and critical, evaluation of the limitations and biases of current iDNA protocols for biodiversity monitoring using both standard and NGS barcoding approaches.
View Article and Find Full Text PDFThe Bermuda fireworm Odontosyllis enopla exhibits an extremely tight circalunar circadian behavior that results in an impressive bioluminescent mating swarm, thought to be due to a conventional luciferase-mediated oxidation of a light-emitting luciferin. In addition, the four eyes become hypertrophied and heavily pigmented, and the nephridial system is modified to store and release gametes and associated secretions. In an effort to elucidate transcripts related to bioluminescence, circadian or circalunar periodicity, as well as epitoky-related changes of the eyes and nephridial system, we examined the transcriptomic profile of three female O.
View Article and Find Full Text PDFThe use of environmental DNA (eDNA) has become an applicable noninvasive tool with which to obtain information about biodiversity. A subdiscipline of eDNA is iDNA (invertebrate-derived DNA), where genetic material ingested by invertebrates is used to characterize the biodiversity of the species that served as hosts. While promising, these techniques are still in their infancy, as they have only been explored on limited numbers of samples from only a single or a few different locations.
View Article and Find Full Text PDFAnnelids possessing a posterior sucker and a fixed number of somites - most famously leeches (Hirudinida), but also crayfish worms (Branchiobdellida) and salmonid parasites (Acanthobdellida) - form a clade; however, determining the relationships between these orders has proven challenging. Here, we compile the largest molecular phylogenetic dataset yet analysed for these groups, including new sequences for key taxa. We find robust model-based support for a clade formed by Hirudinida and Acanthobdellida, contrasting the largest prior studies.
View Article and Find Full Text PDFThe LTR retrotransposon is a selfish endogenous element in the soft-shell clam genome that was first detected because of its dramatic amplification in bivalve transmissible neoplasia afflicting the species. We amplified and sequenced related retrotransposons from the genomic DNA of many other bivalve species, finding evidence of horizontal transfer of retrotransposons from the genome of one species to another. First, the phylogenetic tree of the -like elements from 19 bivalve species is markedly discordant with host phylogeny, suggesting frequent cross-species transfer throughout bivalve evolution.
View Article and Find Full Text PDFLeeches (Annelida: Hirudinea) possess powerful salivary anticoagulants and, accordingly, are frequently employed in modern, authoritative medicine. Members of the almost exclusively marine family Piscicolidae account for 20% of leech species diversity, and they feed on host groups (e.g.
View Article and Find Full Text PDFPlacobdella is a genus of blood-feeding leeches in the family Glossiphoniidae. Historically, species of Placobdella have posed difficulty for systematists owing to a lack of informative morphological characters and the preponderance of inadequate or incomplete species descriptions. Here, we conduct a phylogenetic analysis of 55 individuals representing 20 of the 24 currently recognized nominal taxa using COI, ND1, 12S rDNA and ITS sequences under parsimony, maximum likelihood and Bayesian inference.
View Article and Find Full Text PDFBivalve specimens from legacy frozen tissue collections, and others freshly obtained, were surveyed for the presence of the Steamer long terminal repeat (LTR)-retrotransposon associated with disseminated hemic neoplasia of the soft-shelled clam Mya areneria. Of 22 species investigated using primers for the pol region, only Atlantic M. arenaria, Atlantic and North Sea razor clams Ensis directus, and Baltic clams Macoma balthica from the North Sea were found to possess copies of Steamer in their genomes.
View Article and Find Full Text PDFEvolutionary thinking continues to challenge our views on health and disease. Yet, there is a communication gap between evolutionary biologists and toxicologists in recognizing the connections among developmental pathways, high-throughput screening, and birth defects in humans. To increase our capability in identifying potential developmental toxicants in humans, we propose to apply evolutionary genetics to improve the experimental design and data interpretation with various in vitro and whole-organism models.
View Article and Find Full Text PDFMitochondrial DNA B Resour
June 2016
Mitochondrial DNA sequences, often in combination with nuclear markers and morphological data, are frequently used to unravel the phylogenetic relationships, population dynamics and biogeographic histories of a plethora of organisms. The information provided by examining complete mitochondrial genomes also enables investigation of other evolutionary events such as gene rearrangements, gene duplication and gene loss. Despite efforts to generate information to represent most of the currently recognized groups, some taxa are underrepresented in mitochondrial genomic databases.
View Article and Find Full Text PDFThe common bed bug (Cimex lectularius) has been a persistent pest of humans for thousands of years, yet the genetic basis of the bed bug's basic biology and adaptation to dense human environments is largely unknown. Here we report the assembly, annotation and phylogenetic mapping of the 697.9-Mb Cimex lectularius genome, with an N50 of 971 kb, using both long and short read technologies.
View Article and Find Full Text PDFOne of the recalcitrant questions regarding the evolutionary history of clitellate annelids involves the feeding preference of the common ancestor of extant rhynchobdellid (proboscis bearing) and arhynchobdellid (jaw bearing) leeches. Whereas early evidence, based on morphological data, pointed towards independent acquisitions of blood feeding in the 2 orders, molecular-based phylogenetic data suggest that the ancestor of modern leeches was a sanguivore. Here, we use a comparative transcriptomic approach in order to increase our understanding of the diversity of anticoagulation factors for 3 species of the genus Placobdella, for which comparative data have been lacking, and inspect these in light of archetypal anticoagulant data for both arhynchobdellid and other rhynchobdellid species.
View Article and Find Full Text PDFBackground: The Myxozoa, a group of oligocellular, obligate endoparasites, has long been poorly understood in an evolutionary context. Recent genome-level sequencing techniques such as RNA-seq have generated large amounts of myxozoan sequence data, providing valuable insight into their evolutionary history. However, sequences from host tissue contamination are present in next-generation sequencing reactions of myxozoan tissue, and differentiating between the two has been inadequately addressed.
View Article and Find Full Text PDFInvertebrate-derived DNA (iDNA) from terrestrial haematophagous leeches has recently been proposed as a powerful non-invasive tool with which to detect vertebrate species and thus to survey their populations. However, to date little attention has been given to whether and how this, or indeed any other iDNA-derived data, can be combined with state-of-the-art analytical tools to estimate wildlife abundances, population dynamics and distributions. In this review, we discuss the challenges that face the application of existing analytical methods such as site-occupancy and spatial capture-recapture (SCR) models to terrestrial leech iDNA, in particular, possible violations of key assumptions arising from factors intrinsic to invertebrate parasite biology.
View Article and Find Full Text PDFMitochondrial DNA A DNA Mapp Seq Anal
July 2016
Six complete and three partial actiniarian mitochondrial genomes were amplified in two semi-circles using long-range PCR and pyrosequenced in a single run on a 454 GS Junior, doubling the number of complete mitogenomes available within the order. Typical metazoan mtDNA features included circularity, 13 protein-coding genes, 2 ribosomal RNA genes, and length ranging from 17,498 to 19,727 bp. Several typical anthozoan mitochondrial genome features were also observed including the presence of only two transfer RNA genes, elevated A + T richness ranging from 54.
View Article and Find Full Text PDFMyxozoans are a clade of highly derived cnidarians. The phylogenetic identity of these extremely simplified parasites of aquatic vertebrates and invertebrates had long been uncertain, with all early classifications designating Myxozoa as protists. Though suggestions were frequently made that the infective spores of these parasites are multicellular and possibly of cnidarian origin, it would take a phylogenetic analysis of ultrastructural developmental characters in combination with rRNA gene sequences to verify the Myxozoa as secondarily reduced cnidarians, sister to the polypoidozoan parasite Polypodium hydriforme .
View Article and Find Full Text PDFAn epistemological-evolutionary conception of leeches (Hirudinida) based on features of the female reproductive system in combination with other morphological characters is presented in the spirit of the cladistic school of taxonomy. Characters relating to the structure of the ovary and the course of oogenesis in leeches were interpreted in this manner, for the first time. Each study was conducted on type species of higher taxonomic groups of true leeches.
View Article and Find Full Text PDFBackground: There are at least three distinct European leech species used medicinally: Hirudo medicinalis, H. orientalis, and H. verbana.
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