Single-cell RNA-seq profiling of individual Biomphalaria glabrata immune cells with a focus on immunologically relevant transcripts

An Overview of Transcriptional Responses of Schistosome-Susceptible (M line) or -Resistant (BS-90) Biomphalaria glabrata Exposed or Not to Schistosoma mansoni Infection

“…Notable in category 1 are 77 putative resistance-associated genes ( Table S1 ), including 13 AIG gene family of GTPases ( 73 ), 2 FREPs/FReDs ( 74 ), cadherins, cathepsins L, cytochrome P450s, dual oxidases, ubiquitins, peroxidase, laccase-like, TNF receptor-associated factor 3, Macrophage-expressed gene 1 protein-like isoform X1 and peptidoglycan recognition protein. Mitogen-activated protein kinase kinase kinase 1-like (Bg33194), over-expressed in RES granulocytes ( 47 ) also fell into our category 1. Also of interest were sulfotransferases implicated in stress responses, a mitogen activated kinase, and an ankyrin repeat potentially involved in receptor tyrosine kinase signaling.…”

“…Other features of note were a thioester-containing protein, toll-like receptor 7, lipopolysaccharide binding protein, and NF-kappa B inhibitor. FREP3.2 (Bg204) and fibrinogen-related protein K3 precursor (Bg20380) appeared in category 2 as did C-type lectin domain family 10 member A-like (Bg20382) and Multiple epidermal growth factor-like domains protein 11 (Bg24594), the latter two also found to be over-expressed in SUS hyalinocytes (47). Also of interest were genes encoding a turripepetide ici9.2 like molecule with similarity to other gastropod-produced toxins, an RNA-directed DNA polymerase, and a piwi-like protein that, based on the partial sequence we obtained (Bg31729), was homologous to Bg10170 noted by Bridger et al (24) and subsequently implicated in retrotransposon silencing, epigenetic modification and resistance to Sm (72).…”

“…Many comparisons of susceptible and resistant strains of Bg have been undertaken, involving examination of both constitutive or inherent differences (22,30,(45)(46)(47), and how the strains differ in their responses to experimental exposure to a variety of insults including bacteria, molluscicides and trematodes (45,46,48,49), often but not always Sm. Because this ever-expanding list of studies has turned up a long list of factors potentially associated with resistance or susceptibility to infection, we have summarized their results and candidates (see Table S1), both to facilitate our own subsequent analyses and also to aid others in gaining a full appreciation of literature involved.…”

“…Recently, RNA-Seq has been used to explore responses of lab-reared Biomphalaria to Sm or Schistosoma rodhaini from sympatric or allopatric sources ( 71 ), and was used in a study of early (0.5-16 hours) exposure to Sm in BS-90 Bg to explore the interactions of BgPiwi and the retrotransposon nimbus in influencing resistance ( 72 ). Most recently, single cell transcriptomics methods were applied to isolated granulocytes and hyalinocytes from M line and BS-90 snails not exposed to parasites ( 47 ).…”

The evolution of innate immune receptors: investigating the diversity, distribution, and phylogeny of immune recognition across eukaryotes

“…In contrast, Li et al ( 2021 ) present original findings from the lophotrochozoan Biomphalaria glabrata that complement the reviews in this issue based on single-cell transcriptome sequencing of hemocytes (circulating immune cells). Unlike Drosophila and Caenorhabditis , this gastropod snail has a relatively large genome that contains a robust repertoire of IIRs.…”