Herpes virus OsHV-1 and the protistPerkinsus marinusmodify the expression of the Down syndrome cell adhesion molecule gene in gill and mantle ofCrassostreaspp.

Abstract

The Down syndrome cell adhesion molecule (Dscam) gene in invertebrates encodes numerous isoforms derived by alternative splicing as a pathogen-specific response.The role of Dscam in immune system responses has been established in fruit fly, mosquito, shrimp, crab, and crayfish, among other arthropods. In molluscs, this genehas not yet been clearly identified, and more importantly, its function has not been elucidated. The present study examined Dscam expression in Crassostrea gigas (CgDscam) and Crassostrea corteziensis (CcDscam) infected with Ostreid herpesvirus type 1 (OsHV-1) and Perkinsus marinus, respectively, through in situ hybridization and quantitative PCR. The consensus coding sequences for CgDscam and CcDscam showed the same organization of domains identified in other taxonomic groups. Furthermore, conserved regions from the signal peptide to Ig1 and from FNIII6 to the cytoplasmic tail were identified. The Dscam transcript was detected in gills and mantles of both species. The hybridization signals were remarkable in infected tissues.QPCR analysis showed higher Dscam expression levels in the infected gills of both species, but in the mantle, no difference in CgDscam expression was observed between control and infected tissues. Moreover, CcDscam expression was inhibited in infected tissue. These results suggest that Dscam could be directly involved in bivalve immune responses.

Transcriptomic Signature of Horseshoe Crab Carcinoscorpius rotundicauda Hemocytes’ Response to Lipopolysaccharides

“…In addition to these mechanisms, HSCs release defence molecules stored in secretory granules such as antibacterial substances, serine protease zymogens, coagulogen, protease inhibitors, antimicrobial peptides, and lectins, among others [ 13 , 14 , 15 ]. In addition to the dominant role of the innate immune defence system rudimentary specific immune responses such as the down syndrome cell adhesion molecule (DSCAM) system are also present, as has previously been described in arthropods and other invertebrates [ 16 , 17 , 18 ]. Hemocytes are the pivotal elements in the immune defence of HSCs, activated through the recognition of pathogen-associated molecular patterns (PAMPs) by pattern-recognition receptors (PRRs), which trigger full activation of immune defence mechanisms [ 13 , 19 , 20 ].…”

Unveiling protist diversity associated with the Pacific oyster Crassostrea gigas using blocking and excluding primers

“…However, protists might play a role in oyster homeostasis. For example, C. gigas oysters are infected by several protistan parasites [7][8][9][10][11]. Among them, Marteilia and Pseudoperkinsus genera have negative impacts on the mollusc aquaculture production [12,13].…”