De novotranscriptome characterization of a sterilizing trematode parasite (Microphallussp.) from two species of New Zealand snails

Abstract

Snail-borne trematodes represent a large, diverse, and evolutionarily, ecologically, and medically important group of parasites, often imposing strong selection on their hosts and causing host morbidity and mortality. Even so, there are very few genomic and transcriptomic resources available for this important animal group. We help to fill this gap by providing transcriptome resources from trematode metacercariae infecting two congeneric snail species, Potamopyrgus antipodarum and P. estuarinus. This genus of New Zealand snails has gained prominence in large part through the development of P. antipodarum and its sterilizing trematode parasite Microphallus livelyi into a textbook model for host-parasite coevolutionary interactions in nature. By contrast, the interactions between Microphallus trematodes and P. estuarinus, an estuary-inhabiting species closely related to the freshwater P. antipodarum, are relatively unstudied. Here, we provide the first annotated transcriptome assemblies from Microphallus isolated from P. antipodarum and P. estuarinus. We also use these transcriptomes to produce genomic resources that will be broadly useful to those interested in host-parasite coevolution, local adaption, and molecular evolution and phylogenetics of this and other snail-trematode systems. Analyses of the two Microphallus transcriptomes revealed that the two trematode isolates are more genetically differentiated from one another than are M. livelyi infecting different populations of P. antipodarum, suggesting that the Microphallus infecting P. estuarinus represent a distinct lineage. We also provide a promising set of candidate genes likely involved in parasitic infection and response to salinity stress.

Molecular signatures of the rediae, cercariae and adult stages in the complex life cycles of parasitic flatworms (Digenea: Psilostomatidae)

“…Nevertheless, comparative transcriptomic analysis is indispensable for understanding the origin and evolution of digenean life cycles and could provide new insights for the treatment and prevention of human and animal diseases. Several transcriptomes of digeneans have been sequenced recently [22][23][24][25][26][27][28][29][30][31][32][33][34][35], but in the majority of these studies only adult worms were analyzed [22, 23, 27-31, 33, 35]. Just a few studies analyzed gene expression among different life stages [25,32,34] or compared expression dynamics between the same life stages in the different species [23][24][25][26]35].…”

A new species ofAtriophallophorusDeblock & Rosé, 1964 (Trematoda: Microphallidae) described fromin vitro-grown adults and metacercariae fromPotamopyrgus antipodarum(Gray, 1843) (Mollusca: Tateidae)

“…Metacercaria A of Winterbourn (1974); Microphallus sp. of Lively (1987, 1989), Lively & McKenzie (1991), Jokela & Lively (1995), Dybdahl & Lively (1996, 1998), Levri & Lively (1996), Lively & Jokela (1996), Levri (1999), Krist et al (2000, 2004), Levri & Fisher (2000), Jokela et al (2003, 2009), Dybdahl & Krist (2004), Lively et al (2004, 2008), Osnas & Lively (2004, 2006, 2011), Levri et al (2005), Fromme & Dybdahl (2006), Koskella & Lively (2007, 2009), Lagrue et al (2007), Dybdahl et al (2008), Lagrue & Poulin (2008), Lively et al (2008), King et al (2009, 2011a, b), Koskella et al (2011), Vergara et al (2013, 2014, 2017), Paczesniak et al (2014, 2019), Gibson et al (2016a, b, 2018), McKone et al (2016), Bankers et al (2017), Bankers & Neiman (2017); Microphallus sp. ‘lively’ of Hofmann et al (2016); Microphallus sp.…”

“…‘lively’ of Hofmann et al (2016); Microphallus sp. ‘livelyi’ of Hechinger (2012), Soper et al (2014), Bankers & Neiman (2017); Microphallus livelyi ( nomen nudum ) of Bankers & Neiman (2017). Type host .…”

Phylogeography and cryptic species structure of a locally adapted parasite in New Zealand

“…Dicrocoelium chinensis (Sudarikov & Rizhdcov, 1951) and Dicrocoelium dendriticum (Rudolphi, 1819) were used as outgroup taxa (Genbank KF318786 and KF318787, respectively), while Microphallus sp. 2 LB‐2017 (Genbank SRR5170514) is a closely related Atriophallophorus specimen that was collected from Potamopyrgus estuarinus in New Zealand (Bankers & Neiman, 2017). Sequences were aligned with MAFFT version 7.450 (Katoh et al, 2002; Katoh & Standley, 2013) in Geneious prime® 2020.0.4 (https://www.geneious.com), using the translation align option (FFT‐NS‐i x1000 algorithm; BLOSUM62 scoring matrix; gap opening penalty of 1.53; offset value of 0.2).…”