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The class A scavenger receptors play important roles in innate immunity and are distributed on plasma membrane of macrophages and other cell types. Notably, the class A scavenger receptor 4 (SCARA4) contains a typical C-type (calcium-dependent) lectin domain, which belongs to the collectin family of pattern recognition receptors and is involved in the immune response against infection. Here, one turbot SCARA4 gene was identified with a 2,292 bp open reading frame (ORF) encoding 763 amino acid residues. Multiple sequence analysis and phylogenetic analysis confirmed that SmSCARA4 gene was more close to that of P. olivaceus. Gene structure and syntenic analysis showed conserved exon/intron organization pattern and syntenic pattern across selected vertebrate species. Tissue distribution analysis showed SmSCARA4 was expressed in all the tested healthy tissues with the relative high expression levels in skin, gill and spleen. Following both E. tarda and V. anguillarum challenge in vivo, SmSCARA4 was significantly repressed in gill and intestine. Remarkably, SmSCARA4 showed the strongest binding ability to LPS and strongest upregulation in turbot head kidney macrophages in response to LPS. Knockdown and overexpression of SmSCARA4 revealed its interactions with the two pro-inflammatory cytokines, TNF-α and IL-1β. Finally, repression of SmSCARA4 via combined treatment of LPS and overexpression of SmSCARA4 construct in turbot head kidney macrophages further indicated an inhibitory role of SmSCARA4 in LPS-stimulated inflammation. Taken together, turbot SmSCARA4 plays an important role in turbot immunity, especially in the mucosa-related systems; SmSCARA4 possesses strong binding specificity to LPS, and exerts protective roles in response to LPS infection by reducing the release of pro-inflammatory cytokines. The mechanisms of inhibitory role of SmSCARA4 in LPS-elicited inflammation await further investigation.

C-type lectins (CTLs) are important pathogen pattern recognition receptors that recognize carbohydrate structures. In present study, a C-type lectin domain family 4 member E-like gene from turbot, which tentatively named SmCLEC4E-like (SmCLEC4EL), was identified, and the expressional and functional analyses were performed. In our results, SmCLEC4EL showed conserved synteny with CLEC4E-like genes from several fish species in genome, and possessed a typical type II transmembrane CTL architecture: an N-terminal intracellular region, a transmembrane domain and a C-terminal extracellular region which contained a predicted carbohydrate recognition domain (CRD). In addition, SmCLEC4EL exhibited the highest expression level in spleen in healthy fish, and showed significantly induced expression in mucosal tissues, intestine and skin, under bacteria challenge. Finally, the recombinant SmCLEC4EL protein combined with LPS, PGN, LTA and five different kinds of bacteria in a dose-dependent manner, and agglutinated these bacteria strains in the presence of calcium. These findings collectively demonstrated that SmCLEC4EL, a calcium-dependent CTL, could function as a pattern recognition receptor in pathogen recognition and participate in host anti-bacteria immunity.

The innate immune system plays an important role in host defense against pathogenic infections. In the innate immune system, several families of innate pattern recognition receptors, including Toll-like receptors, RIG-I-like receptors, NOD-like receptors (NLRs), and DNA receptors (cytosolic sensors for DNA), are known to play vital roles in detecting and responding to various pathogens. In this study, we identified 29 NLRs in turbot including 4 NLRs from subfamily A: NOD1, NOD2, CIITA, NLRC5, 1 NLR from subfamily B: NLRB1, 21 NLRs from subfamily C: NLR-C3.1∼NLRC3.21, 1 from NLRX subfamily, and two that do not fall within these subfamilies: APAF1, NWD1. Phylogenetic analysis showed that these NLR genes were clearly divided into five subfamilies. Protein-protein interaction network analysis showed that some of these NLR genes shared same interacting genes and might participate in signal transductions associated with immunity. The evolutionary pressure selection analysis showed that the Ka/Ks ratios for all detected NLR genes were much less than one, implying more synonymous changes than non-synonymous changes. In addition, tissue expression analysis showed that the relative higher expression levels were observed in gill, skin and intestine. Meanwhile, NLR genes expression after bacterial infection results showed that most NLR genes participated in the process of defense of V. anguillarum and A. salmonicida infections in mucosal tissues. Taken together, identification and expression profiling analysis of NLR genes can provide valuable information for further functional characterization of these genes in turbot.

As one of the key components of pattern recognition receptors, Toll-like receptors (TLRs) play pivotal roles in the innate immune system. However, little information is available about the TLR genes in Sebastes schlegelii. In the present study, 17 TLR genes were identified and classified based on the whole genome database. Tandem duplication events in TLR1, TLR2, TLR5 and TLR13 played major role in the expansion of S. schlegelii TLR genes; both TLR2-3 and TLR2-4 had the same largest number of introns/exons, 11 exons and 10 introns. The syntenic analysis showed neighboring genes of TLR genes were most conserved in S. schlegelii and in L. crocea. Phylogenetic and evolutionary analysis showed that these TLR genes were divided into five subfamilies and exhibited different selection pressures. Meanwhile, the expression patterns of TLR genes in the intestine after E. tarda infection were investigated by qRT-PCR. Finally, protein and protein interaction (PPI) network analysis indicated that TLR genes interacted with IFN-inducible genes, inflammatory cytokines, and participated in MyD88-dependent pathway. In summary, this study provided valuable information for further functional characterization of TLR genes in S. schlegelii.

Cathepsin L (CTSL) is one of the crucial enzymes in cathepsin family, which has been widely known for its involvement in the innate immunity. However, it still remains poorly understood how CTSL modulates the immune system of teleosts. In this study, we captured three cathepsin L genes (SmCTSL, SmCTSL.1 and SmCTSL1) from turbot (Scophthalmus maximus). The coding sequences of SmCTSL, SmCTSL.1 and SmCTSL1 are 1,026 bp, 1,005 bp and 1,017 bp in length and encode 341, 334 and 338 amino acids, respectively. In details, transcripts of CTSL genes share same domains as other CTSL genes, one signal peptide, one propeptide and one papain family cysteine protease domain. Protein interaction network analysis indicated that turbot CTSL genes may play important roles in apoptotic signaling and involve in innate immune response. Evidence from subcellular localization demonstrated that the three Cathepsin L proteins were ubiquitous in nucleus and cytoplasm. The cathepsin L genes were widely expressed in all the tested tissues with the highest expression level of SmCTSL in spleen, and SmCTSL.1 and SmCTSL1 in intestine. Following Vibrio anguillarum, Edwardsiella tarda and Streptococcus iniae challenge, these cathepsin L genes were significantly regulated in mucosal tissues in all the challenges, especially significant down-regulation occurred rapidly in intestine in all the three challenges. In addition, the three cathepsin L genes showed strong binding ability to all the examined microbial ligands (LPS, PGN and LTA). Further studies should be used to analyze the specific function of these three cathepsin L genes. By then, we can use their function to maintain the integrity of the mucosal barrier, thereby promoting the disease resistance line and family selection in turbot.

Rhamnose-binding lectin (RBL) were mostly identified from egg cortex and ovary cells from vertebrates and invertebrates, with the specific binding activities to l -rhamnose or d -galactose. Previously, we found that a RBL gene was dramatically down-regulated (−11.90 fold at 1 h, −48.95 fold at 4 h, −905.94 fold at 12 h) in the intestine of turbot following Vibrio anguillarum challenge using RNA-seq expression analysis. In this regard, we sought here to identify RBLs in turbot, as well as the analysis of genomic structure, phylogenetic relationships, basal tissue distribution and the expression patterns following different bacteria challenge in mucosal tissues. In this study, two RBLs were captured in turbot with two conserved type 5 CRD5s, which were belong to type IIIc RBL. In phylogenetic tree analysis, turbot RBLs were clustered with tilapia, European sea bass and snakehead. In addition, in comparison of genomic architecture of turbot RBLs with the available published RBL genes revealed a high degree of conservation in the exon/intron organization among the teleost species. Moreover, both RBLs were significantly up-regulated in mucosal tissues following V. anguillarum and Streptococcus iniae challenge, indicated their critical roles in turbot mucosal immunity. Further studies are needed to expand functional characterization of detailed mechanisms of RBLs in fish innate immunity.

A machine learning model was developed to estimate stem water potential from UAV.An additional model was developed to detect three levels of water stress.Models were developed at pixel-by-pixel and plant by plant scales.Spatial distribution maps were constructed for a grapevine region for irrigation.High accuracy models developed could assist irrigation and grapevine management. Remote sensing can provide a fast and reliable alternative for traditional in situ water status measurement in vineyards. Several vegetation indices (VIs) derived from aerial multispectral imagery were tested to estimate midday stem water potential (stem) of grapevines. The experimental trial was carried out in a vineyard in the Shangri-La region, located in Yunnan province in China. Statistical methods and machine learning algorithms were used to evaluate the correlations between stem and VIs. Results by simple regression between VIs individually and stem showed no significant relationships, with coefficient of determination (R2) for linear fitting smaller than 0.3 for almost all the indices studied, except for the Optimal Soil Adjusted Vegetation Index (OSAVI); R2=0.42 with statistical significance (p0.001). However, results from a model obtained by fitting using Artificial Neural Network (ANN), using all VIs calculated as inputs and real stem from plants within the study site (n=90) as targets (Model 1), showed high correlation between the estimated water potential through ANN (stem ANN) and the actual measured stem. Training, validation and testing data sets presented individual correlations of R=0.8, 0.72 and 0.62 respectively. The models obtained from the study site were then applied to a wider area from the vineyard studied and compared to further stem measured obtained from different sites (n=23) showing high correlation values between stem ANN and real stem (R2=0.83; slope=1; p0.001). Finally, a pattern recognition ANN model (Model 2) was developed for irrigation scheduling purposes using the same stem measured in the study site as inputs and with the following thresholds as outputs: stem below 1.2MPa considered as severe water stress (SS), stem between 0.8 to 1.2MPa as moderate stress (MS) and stem over 0.8MPa with no water stress (NS). This model can be applied to analyze on a plant by plant basis to identify sectors of stress within the vineyard for optimal irrigation management and to identify spatial variability within the vineyards.

Cognitive radar can adjust the transmitted waveform adaptively to the external dynamic environment for a better target tracking performance than the traditional radar transmitting the fixed waveform. There are two key problems in the tracking system of cognitive radar, which are how to build the transmitted waveform library and how to select the optimal waveform for target tracking in the waveform library. The problem of adaptive waveform selection for maneuvering target tracking is studied in this paper. The factors influencing the target tracking accuracy are analyzed, and the maneuvering target tracking framework in cognitive radar is proposed. Considering that the narrow pulses correspond to good delay but poor Doppler resolution capability and that the long constant-frequency pulses have the opposite behavior, we build a transmitted waveform library consisting of the waveforms with both types of properties using the fractional Fourier transform (FrFT) technique. And the criteria for waveform selection in the control theoretic and information theoretic approaches are discussed in detail. The corresponding solutions of waveform selection in the waveform library are given, respectively. The superior performance of the adaptive waveform over the fixed waveform is illustrated with simulation examples. The simulations demonstrate that the target tracking algorithm is also very important for waveform selection.

Toll-like receptor (TLR) family is a key ancient component of pattern recognition receptors, conserved from insects to mammals, which plays significant roles in immune defense against pathogens invasion. Teleost-specific TLR family members have lost some of the mammalian TLR orthologues or produced duplicates, particularly all bacterial could recognize cell surface TLRs. Edwardsiella tarda is an important pathogen of Japanese flounder (Paralichthys olivaceus) resulting in great economic losses. However, there is little integrated information of the roles about TLRs in mediating immune response to E.tarda infection in Japanese flounder. Here, we performed data-mining on the P. olivaceus genome to extract eleven TLR members: TLR1, TLR2, TLR3, TLR5M, TLR5S, TLR7, TLR8, TLR9, TLR18, TLR21 and TLR22. The TLR family motifs, such as Toll/interleukin (IL)-1 receptor (TIR) domain and leucine rich repeat (LRR) are conserved in TLR1-3, 5M, 7-9, 18, 21 and 22. Phylogenetic analysis verified their identities and supported the classification of TLRs into six subfamilies as in other vertebrates. And then, the expression of P. olivaceus TLRs (PoTLRs) were widely detected in immune-related tissues including intestine, skin, spleen, kidney, liver, and gill. Subsequently, the PoTLRs were exhibited differential regulation in immune-related tissues, such as intestine, spleen, liver and kidney following bacterial challenge by infection with E.tarda, indicating their roles in the immune response. The syntenic analysis showed neighboring genes of TLR1, 7, 8 and 18 were relatively conserved among P.olivaceus, O.latipes, and C.semilaevis. Meanwhile, protein and protein interaction network (PPI) results explained that TLR genes interacted with immune-related mediating factors including Interleukin-related genes, e.g. Il1 and Il10, MyD88-dependent pathway, Sarm1 and NF-κB signaling pathway, which could bind to TIR domain. These analyses will contribute to the functional characterization of P. olivaceus TLRs in further study.

Fetuin B (FETUB), a recently described cysteine proteinase inhibitor, has numerous conserved N-glycosylation sites, species-specific O-glycosylation sites, and two cystatin (CY) domains. FETUB is likely to play regulatory roles in acute inflammation, female infertility, fish organogenesis and tumor suppression. In the present study, transcript of turbot FETUB gene was captured, its protein structure and expression patterns in different tissues with emphasis on mucosal barriers following different bacterial infection were characterized. Turbot FETUB gene showed the closest relationship with Takifugu rubripes in phylogenetic analysis. In addition, FETUB was ubiquitously expressed in all examined tissues with the highest expression level in skin. Finally, FETUB gene showed different expression patterns following both bacterial challenge. The rapidly and significantly differential expression patterns of FETUB in mucosal surfaces against bacterial infections might indicate its key roles to prevent pathogen attachment and entry in turbot mucosal immunity. Functional studies should be carried out to further characterize the FETUB and avail utilization of its function to increase the disease resistance of turbot in maintaining the integrity of the mucosal barriers against infections and to facilitate selection of the fine family/varieties of disease resistance in turbot.

Cathepsin F (CTSF) is a recently described papain-like cysteine protease and unique among cathepsins due to an elongated N-terminal pro-region, which contains a cystatin domain. CTSF likely plays a regulatory role in processing the invariant chain which is associated with the major histocompatibility complex (MHC) class II. In this regard, we identified the CTSF gene of turbot as well as its protein structure, phylogenetic relationships, and expression patterns in mucosal tissues following Vibrio anguillarum and Streptococcus iniae challenge. We also determined the expression patterns of CTSF in mucosal tissues after vaccinated with the formalin-inactivated V. vulnificus whole-cell vaccine. Briefly, turbot CTSF gene showed the closest relationship with that of Paralichthys olivaceus in phylogenetic analysis. And CTSF was ubiquitously expressed in all tested tissues with the highest expression level in gill. In addition, CTSF gene showed different expression patterns following different bacterial challenge. The significant quick regulation of CTSF in mucosal surfaces against infection indicated its roles in mucosal immunity. Functional studies should further characterize avail utilization of CTSF function to increase the disease resistance of turbot in maintaining the integrity of the mucosal barriers against infection and to facilitate selection of the disease resistant family/strain in turbot.

Salinity tolerance of yolk-sac larvae and swim-up fry of channel catfish (Ictalurus punctatus), blue catfish (I. furcatus), and hybrid catfish (channel catfish ♀ × blue catfish ♂) was investigated at 0, 3, 6, and 9 ppt salinity. One-hundred percent mortality occurred at 9 ppt. Survivals were different (P hybrid catfish > channel catfish for salinity tolerance. Long-term survival of hybrid fry was better than that of the parent species at 0 ppt salinity, but highest for channel catfish at 3 ppt and 6 ppt with the hybrid being intermediate. NaCl had a negative effect on survival rate of yolk sac larvae starting at 3 ppt and for swim-up fry at 6 ppt. Genotype × environment interactions occurred for growth as hybrids grew faster than channel catfish and blue catfish at 0 ppt. Raising salinity to 3 ppt greatly increased the growth rate (50–75%) of channel catfish and blue catfish, but only slightly (10%) for hybrid catfish, which were still larger than the parent species. 6 ppt was detrimental to yolk-sac larvae and swim-up fry. These results help identify the saline environments that might be suitable for long-term growth and disease resistance of ictalurid catfish, and reveals changes in salinity tolerance during development. Statement of relevance The life stages of channel, blue and hybrid catfish were not previously studied for tolerance of sodium chloride and genotype-environment interations were observed indicating the ideal environment for culture or disease treatment varies among these genetic groups. Heterosis of the hybrids almost disappeared at 3 ppt and growth of channel catfish was greatly enhanced at 3 ppt. Greater Ich resistance of hybrids compared to parents at 0 ppt contradicted earlier reports at older life stages.

The mucosal surfaces constitute the first immune barrier of host defense and also serve as the dynamic interfaces that simultaneously mediate a diverse array of critical physiological processes. It has been long hypothesized that observed difference of disease resistance among different fish strains and species are strongly correlated to the activities of the immune actors in mucosal surfaces. Particularly, neuronal NOS (nNOS or NOS1) is a constitutively expressed gene that catalyzes the oxidation of l-arginine and water to nitric oxide (NO), which is known as a potent host defence effector in immune system with antimicrobial activity. Moreover, NOS1 was detected to be expressed in fish mucosal surfaces, but its activities in mucosal immune responses were always overlooked. In this regard, we identified the NOS1 of turbot and characterized its expression patterns in mucosal tissues following Vibrio anguillarum and Streptococcus iniae challenge. The results showed that the NOS1 gene had a 4389 bp open reading frame (ORF) that encoded 1462 amino acids. Phylogenetic analysis showed the turbot NOS1 had the strongest relationship to Larimichthys crocea. And the syntenic analysis revealed the similar neighboring genes associated with turbot NOS1, compared with other teleost and mammals. In addition, NOS1 was widely expressed in all examined tissues with the highest expression level in brain, followed by intestine and gill. Finally, the NOS1 showed a general trend of up-regulation in mucosal tissues following both bacterial challenge, with the highest up-regulation in intestine. The significant quick induction of NOS1 in mucosal surfaces against infection indicated its key roles to prevent pathogen attachment and entry in mucosal immunity. More functional studies are needed to conduct in teleost to better understand the roles of NOS1 in maintaining the integrity of the mucosal barriers against infection.

Constructs bearing growth hormone (GH) cDNA from channel catfish, Ictalurus punctatus, driven by the ocean pout, Zoarces americanus, antifreeze protein promoter (opAFP), or by the rainbow trout, Oncorhynchus mykiss, metallothionein promoter (rtMT) were transferred to channel catfish via electroporation. Transgenic P1 individuals were mated to produce F1 individuals that exhibited enhanced growth rate. The inheritance of the transgene by the F1 generation was 10% to 36%. The mean body sizes of F1 transgenic fish were larger than their non-transgenic full-siblings (P 0.05) between transgenic and non-transgenic full-siblings except for one opAFP-ccGH family, although the observed means were smaller for four of six transgenic groups as apparently their relative length was increasing more rapidly than relative weight compared to their respective controls. Examining the data from the current experiment and that from an earlier experiment with the same genetic types, but grown to a smaller size, it appears that the two promoters gave similar results in regards to growth enhancement. The largest individuals were always in the transgenic families, and this along with the family effects suggest that gene transfer coupled with combined individual and family selection might result in larger fish than the GH transgenesis alone. The growth enhancement in the current experiment was better than previous experiments with channel catfish that used RSV-LTR-salmonid GH constructs. Assuming government approval and the same growth to food size, GH transgenic channel catfish would increase farm income by $3421/ha compared to use of non-transgenic channel catfish.

Organisms exposed to sub-zero temperatures are at risk of freezing damage. Fingerling channel catfish, Ictalurus punctatus , hybrid catfish (channel catfish female × blue catfish, Ictalurus furcatus , male), channel catfish transgenic for the goldfish glutamate decarboxylase 65 gene driven by the carp β-actin promoter (βA-GAD65), and channel catfish transgenic for the catfish growth hormone gene driven by the antifreeze protein promoter (AFP-ccGH) were compared for survival at different temperatures (9.0 °C, 6.0 °C, 3.0 °C, 1.0 °C, 0.5 °C, 0 °C, and − 0.5 °C) at different salinities (0 ppt, 2.5 ppt, 5 ppt, and 7.5 ppt). The two transgenes were of interest as growth hormone not only affects growth, but also affects osmoregulation, and GAD65 construct could alter gonadotropin with the potential consequence that GnRH affects growth hormone production. Survival was 98–100% for all genetic groups at all salinities between 0 °C and 9.0 °C. However, large differences were observed at − 0.5 °C. At 0 ppt salinity, 100% of AFP-ccGH transgenic (T) fingerlings survived, but survival of all other genetic groups was 0–2%. Raising salinity to 2.5 ppt at sub-zero temperature had a strong positive impact on survival as survival rates of AFP-ccGH (T), AFP-ccGH control (C), channel catfish, βA-GAD65 (T), βA-GAD65 (C) and hybrid catfish were 100, 100, 98, 76, 100 and 18%, respectively. Increasing salinity further to 5 ppt decreased overall survival, although it was still higher than at 0 ppt. Survival rankings were altered, with means for βA-GAD65 (T), βA-GAD65 (C), AFP-ccGH (T), AFP-ccGH (C), channel catfish and hybrid catfish of 69, 0, 15, 22, 0 and 0%, respectively. Mortality was 100% in all genetic groups at − 0.5 °C and 7.5 ppt demonstrating significant interaction between temperature and salinity. Negative heterosis was observed for the hybrids at low temperature at the respective salinities. Statement of relevance We believe that this topic has not been previously addressed. These pleiotropic effects have never been described in GH transgenic or GAD transgenic fish and have relevance for aquaculture/natural resource management for future climate change as well as management and genetic management today. It is the first paper to evaluate the survival of hybrids under freezing, very important for countries that are suffering from freezing weather.

Luteinizing hormone releasing hormone analog (LHRHa, des Gly10, [D-Ala6] ethylamide) is routinely applied for induced spawning of fish. Simulated gastric acid and pepsin were used to mimic human digestion in vitro to determine the stability of LHRHa upon possible ingestion. In vitro cleavage of LHRHa was quantified using UPLC-MS, ultra-performance liquid chromatography-mass spectrometry. LHRHa was broken down mainly into two fragments from Glp-His-Trp-Ser-Tyr-D-Ala-Leu-Arg-Pro-NHEt (LHRHa) to Trp-Ser-Tyr-D-Ala-Leu-Arg-Pro-NHEt (fragment 1) and Ser-Tyr-D-Ala-Leu-Arg-Pro-NHEt (fragment 2). By 24h of incubation, LHRHa was completely digested or barely detectable if the starting material was at 250 ng/μl. If the starting concentration was at 5 ng/μl, LHRHa was completely digested by 5h of incubation, or earlier. In both extreme scenarios, the results indicated that LHRHa would be digested completely in the human stomach and would pose no risk in human food consumption. This study supports the assertion that LHRHa used as a spawning aid would not pose a human food safety risk.

The mucosal surfaces of fish are the first line of host defense against various pathogens. The mucosal immune responses are the most critical events to prevent pathogen attachment and invasion. Cathepsins are a group of peptidases that involved in different levels of immune responses, but the knowledge of the roles of Cathepsin in mucosal immune responses against bacterial infection are still lacking. Therefore, in the present study we characterized the Cathepsin L gene family in channel catfish, and profiled their expression levels after challenging with two different Gram-negative bacterial pathogens. Here, two Cathepsin L genes were identified from channel catfish and were designated CTSL1a and CTSL.1. Comparing to other fish species, the catfish CTSL genes are highly conserved in their structural features. Phylogenetic analysis was conducted to confirm the identification of CTSL genes. Expression analysis revealed that the CTSL genes were ubiquitously expressed in all tested tissues. Following infection, the CTSL genes were significantly induced at most timepoints in mucosal tissues. But the expression patterns varied depending on both pathogen and tissue types, suggesting that CTSL genes may exert disparate functions or exhibit distinct tissue-selective roles in mucosal immune responses. Our findings here, clearly revealed the key roles of CTSL in catfish mucosal immunity; however, further studies are needed to expand functional characterization and examine whether CTSL may also play additional physiological roles in catfish mucosal tissues.

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. The objectives of this study were to examine relative transcripts linked to egg and embryo quality and determine expression between low-hatch and high-hatch egg batches through early development (0, 24, 48, and 96 h post-fertilization; HPF). RNA was extracted from eggs/embryos of nine females (n = 4 high-quality, n = 5 low-quality) and Real-Time PCR was used to quantify relative gene expression. The transcripts assessed in this study perform critical cellular functions, including tubulin β (tubb), cathepsin D (ctsd), cathepsin Z (ctsz), cathepsin B (ctsb), cyclin B (ccnb1), exportin-1 (xpo1), ring finger protein 213 (rnf213), glucocorticoid receptor-1 (GR-1), and heat shock protein 70 (hsp70). Relative gene expression of all transcripts except GR-1 and hsp70 were up-regulated in the high-hatch group and peaked at 48 HPF (neurulation stage), indicating the importance of these gene products at this threshold to normally progress until hatch. Due to lack of expression during earlier stages, maternally derived mRNAs for these genes do not seem to impact early embryonic development. Using mRNA markers as a selection mechanism for hatchery broodstock may lead to more high-hatch egg batches by reducing problems associated with poor egg quality.

Fish are covered by a watery gel–mucus, mainly secreted by the goblet cells, serving as the physical and biochemical barrier between the external environment and the interior milieu, playing more important roles in fish that without scale. Despite the important roles of mucus in fish immunity, the knowledge of detailed molecular events happened during infection process is still limited. While most studies were focused on characterizing the protein and enzyme activities in the mucus following challenge, no studies have examined the gene expression profiles in fish mucus. In this regard, herein we carried out the first gene profiling analysis in catfish mucus using real-time PCR. Ten important immune-related genes were selected according to our previous studies. Their expression levels were examined in the early timepoints (namely, 1 h, 2 h, 4 h, 8 h, and 24 h) following Flavobacterium columnare challenge. Notably, expression levels of most of the selected genes were rapidly altered by the challenge. Seven genes were down-regulated, while only three genes were up-regulated. In addition, the gene expression patterns in mucus were very different from the mucosal surfaces (skin, gill and intestine) and the classical immune organs (liver, spleen and kidney). The unique expression patterns obtained here may be resulted from the great advantage of the large amount of attached bacteria in the mucus than the internal tissues, and resulted from the bacteria virulent actors to suppress the host immune response. Taken together, our results can expand our knowledge of fish mucosal immunity, and the un-lethal mucus sampling can provide early insight for developing the strategies for selection of disease resistant families and strains in catfish as well as other fish species.

Common carp, Cyprinus carpio, is one of the most widely grown aquaculture species. Four types of knock-down constructs designed to transgenically sterilize fish were electroporated into common carp embryos to knockdown or eliminate expression of primordial germ cell (PGC) proteins, nanos or dead end. Embryos from different developmental stages were collected and tested using quantitative real-time PCR. Relative levels of gene expression were compared among control embryos and embryos exposed to these constructs during development. Two proteins, nanos and dead end, were targeted, each specific for a set of constructs, and a third related, but non-targeted PGC protein, vasa, was assayed. The effectiveness of the constructs varied depending upon the promoter. The expression levels of these proteins naturally decreased during development. In some, but not all cases, the expression of targeted mRNA was knocked down to minimal levels or degradation was accelerated. Up-regulation also was observed for dead end, possibly due to interferon responses. In other cases, the sterilization constructs had little effect on the targeted gene, but strongly down-regulated one or two of the alternative PGC genes examined in this study. At 19 months of age, common carp males exposed to these constructs had reduced rates of sexual maturity; however, reduction of female rates of sexual maturity was not conclusively shown. These constructs appear promising for transgenic sterilization of common carp.

We describe and compare normal eye, unilateral microphthalmia (small eye), and unilateral anophthalmia (eye incompletely developed) in young (5–7 month-old) common carp, Cyprinus carpio , (Cypriniformes: Cyprinidae). Five of 1058 (0.47%) common carp had grossly-observed eye deformities that we characterized using osteology and histopathology: 2 (81 and 98 mm fork length) had unilateral microphthalmia and 3 (103, 123, and 137 mm in fork length) had unilateral anophthalmia. Grossly, the eye of the microphthalmic common carp was opaque and slightly protruding from a reduced orbit; whereas, only a slight integumental concavity was observed on the deformed side of the anophthalmic common carp. Osteologically, microphthalmic and anophthalmic common carp had an irregular orbit with orbital bones that were laterally-expanded and that formed a discontinuous, uneven orbital perimeter compared to the narrow orbital bones forming a nearly circular orbit in normal common carp. Histologically, microphthalmia manifested as an eye having a thickened cornea with a retina and attached optic nerve but no lens (aphakia); whereas, anophthalmia manifested as lacking a globe, cornea, lens, or retina but having a nerve fascicle and capillaries representing probable optic nerve and its associated choroid. No histological sign of infection was observed in the ocular region of any common carp studied. The etiological agent associated with microphthalmia and anophthalmia is indeterminate, and the hypothesis that electroporation caused the ocular deformity was not tested herein. We suspect that the microphthalmic eye could detect light but not form a focused image. A list of putatively similar abnormalities in other fishes as well as anisophthalmia (incomplete eye development) and symmetrical cyclopia (medially fused eye) in larval and juvenile fishes is provided. This is the first published report providing osteological or histopathological details of microphthalmia or anophthalmia in a non-embryonic or non-larval fish.

Adoption of the hybrid catfish (channel catfish, Ictalurus punctatus , female × blue catfish I. furcatus , male) is increasing in the catfish industry. The most effective way to produce fry is hormone induced spawning of females coupled with hand stripping and in vitro fertilization. The success of common carp pituitary extract (CPE), luteinizing hormone releasing hormone analog (LHRHa) injections and LHRHa implants for producing hybrid catfish fry was investigated over the past 15 years. Data from 65 studies, 25, 20 and 20 for CPE, LHRHa injections, and LHRHa implants, respectively, were evaluated. Mean fry/kg female body weight (all females) produced was 948, 2483 and 2765 for CPE, LHRHa injections, and LHRHa implants, respectively. LHRHa administered as an injection or implant produced more (P

The objective of this study was to design a new water level sensor for irrigation water measurement to reduce the investment of water measuring equipment required for agriculture management. Based on ultrasonic pulse-echo technology, a new hardware structure including an ultrasonic transmission circuit, echo receiver circuit, data output circuit and micro control unit (MCU) were described in this paper. A specially designed pulse transformer and a drive circuit based on the NEC555 were used to improve the driving capability for ultrasonic transducers. A low cost but has a high quality for accepting circuit was adopted based on Sony Corporation's infrared demodulator, CX20106A. Output circuit which based on the RS232 interface using multichannel RS-232 Drivers-Receivers MAX232 was used to output the dates, this circuit is simple and easy to extend. In addition, an IC card (corn is 64K SPI Bus Serial EEPROM, AT24C64) based correction parameters input circuit was adopted. Furthermore, some factors, such as temperature, water surface fluctuation and process response time etc. which influence accuracy were discussed. Then, the corresponding corrections methods not only include hardware methods but also include software methods were proposed. A temperature detection module which based on a digital sensor, the Dallas Semiconductor ™ DS18B20, was added to the hardware systems. At the same time, in order to reduce the process response time of program written in C51 language in the MCU control system, the integration programming technology using C51 language and assembler language was used. Besides, voltage conversion and power supply circuits based on three-port voltage regulator circuit LM7805 and LM7808 was designed. The test result shows that this design has a high accuracy and stability. It is possible to get water level data with small errors, and this design reduces the production cost.