Ultrastructural Features of Three Ectocommensal Protozoa Attached to the Gills of the Red Swamp Crawfish,Procambarus clarkii (Crustacea: Decapoda)1

Because heavy branchial infestations are thought to interfere with respiration, we examined the attachment of three stalked ciliates commonly found in the branchial chambers of Louisiana crawfish. Attachments by Cothurnia sp., Epistylis sp. and Acineta sp. differ in their fine structure. Stalks of the peritrichous ciliates. Cothurnia and Epistylis, contain striated tubules that differ in their arrangement, diameter, and in the periodicity of their striations. In both species the striated tubules branch within the basal disk and attach to a pad of adhesive material secreted by the organism during initial attachment to the gill surface. The stalk of the suctorian Acineta is composed of a striated honeycomb-like matrix. Within the basal disc the matrix is disorganized; however, striated elements anchor the stalk to a pad of adhesive material. Attachment sites also differ in the amount of secretory material deposited. Cothurnia forms a multi-layered, granular pad; Epistylis forms an indistinct, microfibrillar layer, and Acineta deposits a thick mucoid pad. None of the ciliates appear to damage the gill epicuticle nor is there an obvious host response. Harmful effects are probably limited to a decrease in respiratory surface area and disruption of normal water flow patterns. This may impair respiration sufficiently to increase the susceptibility of crawfish to low dissolved oxygen concentrations encountered periodically in commercial crawfish ponds.     

Transcriptome Analysis Reveals Candidate Genes Involved in Low Temperature Stress in Bell Pepper

Russian Journal of Plant Physiology - Despite cold stress is a critical environmental condition that influences the growth and development of bell pepper (Capsicum annuum L.), the underlying...     

Prohibitin Interacts with Envelope Proteins of White Spot Syndrome Virus and Prevents Infection in the Red Swamp Crayfish,Procambarus clarkii

Prohibitins (PHBs) are ubiquitously expressed conserved proteins in eukaryotes that are associated with apoptosis, cancer formation, aging, stress responses, cell proliferation, and immune regulation. However, the function of PHBs in crustacean immunity remains largely unknown. In the present study, we identified a PHB in Procambarus clarkii red swamp crayfish, which was designated PcPHB1. PcPHB1 was widely distributed in several tissues, and its expression was significantly upregulated by white spot syndrome virus (WSSV) challenge at the mRNA level and the protein level. These observations prompted us to investigate the role of PcPHB1 in the crayfish antiviral response. Recombinant PcPHB1 (rPcPHB1) significantly reduced the amount of WSSV in crayfish and the mortality of WSSV-infected crayfish. The quantity of WSSV in PcPHB1 knockdown crayfish was increased compared with that in the controls. The effects of RNA silencing were rescued by rPcPHB1 reinjection. We further confirmed the interaction of PcPHB1 with the WSSV envelope proteins VP28, VP26, and VP24 using pulldown and far-Western overlay assays. Finally, we observed that the colloidal gold-labeled PcPHB1 was located on the outer surface of the WSSV, which suggests that PcPHB1 specifically binds to the envelope proteins of WSSV. VP28, VP26, and VP24 are structural envelope proteins and are essential for attachment and entry into crayfish cells. Therefore, PcPHB1 exerts its anti-WSSV effect by binding to VP28, VP26, and VP24, preventing viral infection. This study is the first report on the antiviral function of PHB in the innate immune system of crustaceans.     

Transcriptome Analysis Reveals Candidate Genes Involved in Anthocyanin Biosynthesis in Flowers of the Pagoda Tree (Sophora japonica L.)

Journal of Plant Growth Regulation - The flowers of pagoda tree (Sophora japonica L.) are white, which limited its ornamental value and caused few researches on its flower color and anthocyanin...     

Shelter availability reduces the effects of the invasive Red Swamp Crayfish (Procambarus clarkii) on eelgrass-dominated clear-water lakes: a mesocosm approach

Hydrobiologia - Shelter availability is one of the key features governing crayfish habitat quality. It can directly influence crayfish’s individual survival of by lowering the risk of...     

Transcriptome Analysis Reveals Candidate Lignin-Related Genes and Transcription Factors in Rosa roxburghii During Fruit Ripening

Plant Molecular Biology Reporter - The high lignin content of Rosa roxburghii fruits imparts a strong rough taste, which has restricted its use in industry. Little is known about the molecular...     

Comprehensive Transcriptome Analysis of Gonadal and Somatic Tissues for Identification of Sex-Related Genes in the Largemouth Bass Micropterus salmoides

Marine Biotechnology - Largemouth bass (Micropterus salmoides) is an economically important fish. It can spawn many times during a breeding season, and there are no obvious morphological...