Profiling of adhesive-related genes in the freshwater cnidarianHydra magnipapillataby transcriptomics and proteomics

Abstract

The differentiated ectodermal basal disc cells of the freshwater cnidarian Hydra secrete proteinaceous glue to temporarily attach themselves to underwater surfaces. Using transcriptome sequencing and a basal disc-specific RNA-seq combined with in situ hybridisation a highly specific set of candidate adhesive genes was identified. A de novo transcriptome assembly of 55,849 transcripts (>200 bp) was generated using paired-end and single reads from Illumina libraries constructed from different polyp conditions. Differential transcriptomics and spatial gene expression analysis by in situ hybridisation allowed the identification of 40 transcripts exclusively expressed in the ectodermal basal disc cells. Comparisons after mass spectrometry analysis of the adhesive secretion showed a total of 21 transcripts to be basal disc specific and eventually secreted through basal disc cells. This is the first study to survey adhesion-related genes in Hydra. The candidate list presented in this study provides a platform for unravelling the molecular mechanism of underwater adhesion of Hydra.

Genome evolution and host‐microbiome shifts correspond with intraspecific niche divergence within harmful algal bloom‐forming Microcystis aeruginosa

“…Further supporting an increased occurrence of genomic heterogeneity among LL/LG colonies, we found increased frequencies of genes in LL/LG genomes that may facilitate nonclonal colony formation: (a) NeuB that synthesizes sialic acids, which are a component of cyanobacterial extracellular polymeric substances (Strom, Bright, Fredrickson, & Brahamsha, ; Zippel & Neu, ) and play important roles in cellular recognition and adhesion (Gunawan et al, ); (b) sialidases that may facilitate cellular adhesion by uncovering carbohydrate receptors that are recognized by bacterial adhesins (Vimr, ); (c) pfam06229 (FRG1‐like domain) that contains a Hydra spp. gene linked to this freshwater cnidarian's ability to adhere to underwater surfaces (Rodrigues et al, ); and (d) a bacterial adhesin (pfam03865: haemolysin secretion/activation protein ShlB/FhaC/HecB) (Moslavac et al, ) that facilitates adhesion to other cells in pathogenic and symbiotic interactions (Hooper & Gordon, ). Genes regulating cell recognition and adhesion should be less important for clonal colonies, where daughter cells remain attached after binary fission (Kessel & Eloff, ).…”

“…(c) pfam06229 (FRG1-like domain) that contains a Hydra spp. gene linked to this freshwater cnidarian's ability to adhere to underwater surfaces (Rodrigues et al, 2016); and (d) a bacterial adhesin (pfam03865: haemolysin secretion/activation protein ShlB/FhaC/ HecB) (Moslavac et al, 2005) that facilitates adhesion to other cells in pathogenic and symbiotic interactions (Hooper & Gordon, 2001). Genes regulating cell recognition and adhesion should be less important for clonal colonies, where daughter cells remain attached after binary fission (Kessel & Eloff, 1975).…”

RNA-Seq reveals a central role for lectin, C1q and von Willebrand factor A domains in the defensive glue of a terrestrial slug

“…C-lectin domains have been shown to serve as interfacial linkers, joining soft tissues to the byssus of the fan shell Atrina pectinata (Yoo et al 2016). Galactose-binding lectin domains have been detected in sea star and sea urchin adhesive proteins (Hennebert et al 2014; Lebesgue et al 2016), as well as proteins from the adhesive disk of the freshwater cnidarian Hydra (Rodrigues et al 2016). These proteins may be discoidin-like (Hennebert et al 2015; Lebesgue et al 2016), as was found for one of the H-lectins in slug glue.…”

Whole-body imaging of neural and muscle activity during behavior inHydra: bidirectional effects of osmolarity on contraction bursts

“…translocation of the foot from one place to another. This is initiated by 'foot detachment' where the basal disk detaches from a substrate's surface (Rodrigues, Ostermann et al 2016). Here we tested how these two common behaviors of Hydra are affected by various physiological and environmental conditions.…”