Identification and characterization of two novel peritrophic membrane (PM) genes in the Chinese mitten crab Eriocheir sinensis that exhibit activity against high-pH stress and Aeromonas hydrophila challenge

Abstract

The peritrophic membrane (PM) is located in the gut of most insects and protects them from invasion by pathogens or toxins ingested during feeding. Peritrophins are a principal component of the PM and contribute to the structure and function of the PM. The PM has also been observed in the gastrointestinal tract of the Chinese mitten crab (Eriocheir sinensis). In this study, full‐length cDNA sequences of two PM genes from E. sinensis were obtained, namely, Es‐peritrophin1 and Es‐peritrophin2, which were 855 bp and 1,611 bp respectively. The deduced proteins were composed of 267 and 468 amino acids and contained 3 and 1 chitin binding domains respectively. Both Es‐peritrophin1 and Es‐peritrophin2 contained a signal peptide sequence at the N terminus, indicating that both proteins were secretory proteins. Phylogenetic analysis revealed that Es‐peritrophin1 and Es‐peritrophin2 were divided into the CPAP3‐B and CPAP1‐H branches respectively. Nevertheless, sequence alignment demonstrated that they had lower homology to other known PMs, indicating they were two novel peritrophins. Quantitative real‐time PCR (qRT‐PCR) analysis showed that both the Es‐peritrophin1 and Es‐peritrophin2 transcript levels were high in the stomach and hindgut and lower in the midgut, indicating that the PM might be assembled locally in E. sinensis. The expression of Es‐peritrophin1 and Es‐peritrophin2 was downregulated by high‐pH stress and Aeromonas hydrophila challenge in the examined tissues except in the hindgut, where the expression of both genes was upregulated by A. hydrophila challenge. These results indicated that Es‐peritrophin1 and Es‐peritrophin2 are two novel peritrophin genes related to immune defence in E. sinensis.

Peritrophin-like Genes Are Associated with Delousing Drug Response and Sensitivity in the Sea Louse Caligus rogercresseyi

“…Furthermore, characterized C. rogercresseyi peritrophins presented two or three ChBD2s. Similar results have been reported in crustacean species, Fenneropenaeus Chinensis , P. monodon , Penaeus semisulcatus, and E. sinensis [ 44 , 50 , 51 ]. In addition, more than three ChBD2 domains have been described for insect peritrophins [ 77 ].…”

“…The Chinese mitten crab Eriocheir sinensis has the Es-peritrophin1 whit a MW of 28.93 KDa. However, for this crab was also reported the Es-peritrophin2 with 51.17 KDa [ 50 ]. Additionally, the pI found in the peritrophin-like proteins of C. rogercresseyi were in a range between 4.5 and 6, which is common among other peritrophins [ 39 ].…”

“…Herein, six peritrophin-like proteins identified in C. rogercresseyi presented the chitin-binding domain (ChBD2). This domain allows the assembly of the proteins and chitin fibers forming the PM [ 18 , 50 , 78 ]. Differences in the number of Cys were reported in a family of crustacean peritrophin-like proteins [ 24 ].…”

“…In crustaceans, the presence of PM and homologous insect peritrophin genes have been described [ 23 , 42 , 43 , 44 , 45 , 46 ]. For instance, peritrophin-like genes have been identified in crustaceans such as shrimp [ 23 , 44 , 45 , 47 , 48 , 49 ] and Chinese mitten crab [ 50 , 51 ]. Moreover, Lai and Aboobaker [ 24 ] reported a new family of 80 peritrophin-like genes from a transcriptomic database of 55 crustaceans from the Malacostraca class.…”

Effects of xylan and cottonseed meal on growth performance, digestion, intestinal morphology and the expression of two peritrophin genes of Chinese mitten crab,Eriocheir sinensis

“…The PM was believed to protect the gut epithelia, facilitate digestion (Agrawal et al, ) and neutralize ingested toxic compounds found in plants (Zhao et al, ). Our previous studies showed the expression of PM genes, Es‐PL44 (Gen Bank accession number: ) and Es‐PP1 (Gen Bank accession number: ), that are involved in the structure and digestive function of PM in hindgut of Chinese mitten crab (Li et al, ) exhibit activity against high pH stress and Aeromonas hydrophila challenge (Wang et al, ) and were modulated by diet ingredients (Ren et al, in press).…”