Extraordinary diversity of the CD28/CTLA4 family across jawed vertebrates.

Members of the CD28 family are critical for the control of immune cell activation. While CD28 and CTLA4 were previously identified in teleost fish, most members of the CD28 family have been described only in tetrapods. Using a comparative genomics approach, we found (co)orthologs of all members of the CD28 family both in Chondrichthyes and basal Osteichthyes groups, but not in Agnathans.

Costimulatory receptors in the channel catfish: CD28 family members and their ligands.

The CD28-B7 interaction is required to deliver a second signal necessary for T-cell activation. Additional membrane receptors of the CD28 and B7 families are also involved in immune checkpoints that positively or negatively regulate leukocyte activation, in particular T lymphocytes. BTLA is an inhibitory receptor that belongs to a third receptor family.

A subset of leukocyte immune-type receptors (LITRs) regulates phagocytosis in channel catfish (Ictalurus punctatus) leukocytes.

Channel catfish, Ictalurus punctatus, leukocyte immune-type receptors (LITRs) constitute a large family of paired, immunoregulatory receptors unique to teleosts. A role for LITRs in phagocytosis has been proposed based on studies in mammalian cell lines; however, LITR-mediated phagocytosis has not been examined in the catfish model. In this study, we use two anti-LITR monoclonal antibodies, CC41 and 125.

Interferons and interferon receptors in the channel catfish, Ictalurus punctatus.

In this work, we describe the complete repertoire of channel catfish, Ictalurus punctatus, IFNs and IFN receptor genes. Based on multiple genomic and transcriptomic resources we identified 16 type I IFN genes, which represent the six type I IFN subgroups previously defined in salmonids (a-f.) No representatives of subgroup h previously only found in percomorphs were identified.

A Comprehensive Annotation of the Channel Catfish () T Cell Receptor Alpha/Delta, Beta, and Gamma Loci.

The complete germline repertoires of the channel catfish, , T cell receptor (TR) loci, TRAD, TRB, and TRG were obtained by analyzing genomic data from PacBio sequencing. The catfish TRB locus spans 214 kb, and contains 112 TRBV genes, a single TRBD gene, 31 TRBJ genes and two TRBC genes. In contrast, the TRAD locus is very large, at 1,285 kb.

Use of Dual RNA-seq for Systems Biology Analysis of and Interaction.

The interaction between and is complex, and the identification of plant genes and pathways conferring resistance to the fungus has been challenging. Therefore, the authors undertook a systems biology approach involving dual RNA-seq to determine the simultaneous response from the host and the pathogen. What was dramatically highlighted in the analysis is the uniformity in the development patterns of gene expression of the host and the pathogen during infection.

Analysis of specific mRNA gene expression profiles as markers of egg and embryo quality for hybrid catfish aquaculture.

Despite best efforts to optimize reproduction, egg incubation, and larval performance in captivity, inconsistencies in hatchery fish production are still created by high variations in egg quality from individual females. In some hatchery species, egg quality and generation of viable embryos are correlated to abundances of specific mRNAs. Channel catfish females show considerable extremes in egg quality, causing inconsistencies in channel catfish, Ictalurus punctatus, female × blue catfish, Ictalurus furcatus, male hybrid fry production.

Cloning and characterization of antiviral cytotoxic T lymphocytes in channel catfish, Ictalurus punctatus.

To determine the role of piscine anti-viral cytotoxic cells, we analyzed the response of channel catfish to Ictalurid herpesvirus 1, commonly designated channel catfish virus (CCV). Peripheral blood leukocytes (PBL) from catfish immunized with MHC-matched, CCV-infected G14D cells (G14D-CCV) showed marked lysis of G14D-CCV but little to no lysis of uninfected allogenic (3B11) or syngeneic (G14D) cells. Expansion of effectors by in vitro culture in the presence of irradiated G14D-CCV cells generated cultures with enhanced cytotoxicity and often broader target range.

Catfish lymphocytes expressing CC41-reactive leukocyte immune-type receptors (LITRs) proliferate in response to Edwardsiella ictaluri infection in vitro.

Monoclonal antibodies (mAbs) CC34 and CC41 recognize overlapping subsets of leukocyte immune-type receptors (LITRs). The mAb CC34 was raised against the clonal TS32.15 cytotoxic T cell line and the mAb CC41 was raised against the clonal NK cell line TS10.

Characterization of a third ghrelin receptor, GHS-R3a, in channel catfish reveals novel expression patterns and a high affinity for homologous ligand.

A novel third channel catfish growth hormone secretagogue (ghrelin) receptor, GHS-R3a, gene was characterized. Identification and analysis of the genomic organization of channel catfish GHS-R3a revealed differences in exon/intron structure relative to the previously published GHS-R1a and GHS-R2a sequences. Amino acid sequence alignment of catfish GHS-R3a with -R1a and -R2a revealed 48 and 52% sequence identity, respectively.

Insights into the dynamics of memory, effector and apoptotic cytotoxic T lymphocytes in channel catfish, Ictalurus punctatus.

In this study, we used the channel catfish model clonal TS32.15 alloantigen-specific cytotoxic T cell (CTL) line to examine the dynamics of memory CTL expansion and senescence in teleosts. Although TS32.

Characterization of two channel catfish, Ictalurus punctatus, glucocorticoid receptors and expression following an acute stressor.

Two channel catfish glucocorticoid receptor genes, ipGR1 (NR3C1_1) and ipGR2 (NR3C1_2) were partially characterized. Identification and analysis of the genomic organization of two channel catfish glucocorticoid (GC) receptors (GRs) revealed differences in the lengths of exons 1 and 2 and the addition of an extra 27-bp exon inserted after exon 2 in the GR1 gene, yielding a 9-aa insert in the receptor protein. Sequence of the 9-aa insert in ipGR1 (WRARQNTHG) is unique compared to other teleost fish GRs.

Myxobolus ictiobus n. sp. and Myxobolus minutus n. sp. (Cnidaria: Myxobolidae) from the gills of the smallmouth buffalo Ictiobus bubalus Rafinesque (Cypriniformes: Catostomidae).

The smallmouth buffalo Ictiobus bubalus Rafinesque (Catostomidae) is native to North American waterways and occasionally grown in pond aquaculture. Species of Myxobolus Bütschli, 1882 have been reported from the gills, integument, and intestinal tract of buffalo fish, although there is ambiguity in some host records. In the summer of 2013, thirteen adult smallmouth buffalo were seined from a 0.

A Leukocyte Immune-Type Receptor Subset Is a Marker of Antiviral Cytotoxic Cells in Channel Catfish, Ictalurus punctatus.

Channel catfish, Ictalurus punctatus, leukocyte immune type receptors (LITRs) represent a multigene family that encodes Ig superfamily proteins that mediate activating or inhibitory signaling. In this study, we demonstrate the use of mAb CC41 to monitor viral cytotoxic responses in catfish and determine that CC41 binds to a subset of LITRs on the surface of catfish clonal CTLs. Homozygous gynogenetic catfish were immunized with channel catfish virus (CCV)-infected MHC-matched clonal T cells (G14D-CCV), and PBL were collected at various times after immunization for flow cytometric analyses.

Biomphalaria straminea (Mollusca: Planorbidae) as an intermediate host of Drepanocephalus spp. (Trematoda: Echinostomatidae) in Brazil: a morphological and molecular study.

Species of trematodes belonging to the genus Drepanocephalus are intestinal parasites of piscivorous birds, primarily cormorants (Phalachrocorax spp.), and are widely reported in the Americas. During a 4-year malacological study conducted on an urban lake in Brazil, 27-collar-spined echinostome cercariae were found in 1665/15,459 (10.

Identification of SHIP-1 and SHIP-2 homologs in channel catfish, Ictalurus punctatus.

Src homology domain 2 (SH2) domain-containing inositol 5'-phosphatases (SHIP) proteins have diverse roles in signal transduction. SHIP-1 and SHIP-2 homologs were identified in channel catfish, Ictalurus punctatus, based on sequence homology to murine and human SHIP sequences. Full-length cDNAs for catfish SHIP-1 and SHIP-2 (IpSHIP-1 and IpSHIP-2) were obtained using 5' and 3' RACE protocols.

Small subunit ribosomal RNA sequence links the myxospore stage of Henneguya mississippiensis n. sp. from channel catfish Ictalurus punctatus to an actinospore released by the benthic oligochaete Dero digitata.

There are more than 200 species of Henneguya described from fish. Of these, only three life cycles have been determined, identifying the actinospore and myxospore stages from their respective hosts. Two of these life cycles involve the channel catfish (Ictalurus punctatus) and the freshwater oligochaete Dero digitata.

18S rRNA gene sequencing identifies a novel species of Henneguya parasitizing the gills of the channel catfish (Ictaluridae).

In the southeastern USA, the channel catfish Ictalurus punctatus is a host to at least eight different species of myxozoan parasites belonging to the genus Henneguya, four of which have been characterized molecularly using sequencing of the small subunit ribosomal RNA (SSU rRNA) gene. However, only two of these have confirmed life cycles that involve the oligochaete Dero digitata as the definitive host. During a health screening of farm-raised channel catfish, several fish presented with deformed primary lamellae.

Chronic pathology and longevity of Drepanocephalus spathans infections in juvenile Channel Catfish.

Drepanocephalus spathans (Digenea: Echinostomatidae) is a common parasite of the double-crested cormorant Phalacrocorax auritus. The cercariae of D. spathans have been shown infective to juvenile Channel Catfish Ictalurus punctatus.

Identification and characterization of TCRγ and TCRδ chains in channel catfish, Ictalurus punctatus.

Channel catfish, Ictalurus punctatus, T cell receptors (TCR) γ and δ were identified by mining of expressed sequence tag databases, and full-length sequences were obtained by 5'-RACE and RT-PCR protocols. cDNAs for each of these TCR chains encode typical variable (V), diversity (D), joining (J), and constant (C) regions. Three TCRγ V families, seven TCRγ J sequences, and three TCRγ C sequences were identified from sequencing of cDNA.

Molecular and morphological characterization of myxozoan actinospore types from a commercial catfish pond in the Mississippi delta.

The actinospore diversity of infected Dero digitata was surveyed (May 2011) from a channel catfish (Ictalurus punctatus) production pond in the Mississippi Delta region for the elucidation of unknown myxozoan life cycles. At present, only 2 myxozoan life cycles have been molecularly confirmed in channel catfish, linking the actinospore stage from an aquatic oligochaete (D. digitata ) and the myxospore stage from the catfish.

Lactococcosis in Silver Carp.

An adult Silver Carp Hypophthalmichthys molitrix with a focally extensive skin lesion near the caudal peduncle and mild iridial hemorrhage was submitted to the Aquatic Research and Diagnostic Laboratory (ARDL) in Stoneville, Mississippi, as part of a fish kill investigation. Touch impressions of this musculoskeletal lesion revealed small cocci (∼1 μm) in pairs or chains within an inflammatory milieu. A pure Gram-positive cocci isolate was obtained from the brain, while cultures of the kidney and muscle yielded multiple bacterial colony types, including the Gram-positive cocci seen in the brain.

Edwardsiella piscicida identified in the Southeastern USA by gyrB sequence, species-specific and repetitive sequence-mediated PCR.

A new Edwardsiella taxon was recently described from fishes of Europe and Asia. Phenotypically similar to E. tarda, extensive genetic and phenotypic characterization determined this new strain does not belong to any established Edwardsiella taxa, leading to the adoption of a new taxon, E.

Transcriptional regulation of teleost Aicda genes. Part 1 - suppressors of promiscuous promoters.

In order to better understand antibody affinity maturation in fishes we sought to identify gene regulatory elements that could drive expression of activated B-cell specific fluorescent reporter transgenes in zebrafish. Specifically the promoter and several non-coding regions of the channel catfish (Ictalurus punctatus) and zebrafish (Danio rerio) were tested for transcriptional activity using a dual luciferase reporter system in transfected fish leukocytes and two mammalian cell lines that constitutively express Aicda (activation-induced cytidine deaminase). The promoters of both fish Aicda genes were as transcriptionally active as an SV40 promoter control in all cell lines tested, regardless of the cells ability to express Aicda.