Fish Invertebrates Research Articles

An arms race between 5’ppp-RNA virus and its alternative recognition receptor MDA5 in RIG-I-lost teleost fish

The incessant arms race between viruses and hosts has led to numerous evolutionary innovations that shape life’s evolution. During this process, the interactions between viral receptors and viruses have garnered significant interest since viral receptors are cell surface proteins exploited by viruses to initiate infection. Our study sheds light on the arms race between the MDA5 receptor and 5’ppp-RNA virus in a lower vertebrate fish, Miichthys miiuy. Firstly, the frequent and independent loss events of RIG-I in vertebrates prompted us to search for alternative immune substitutes, with homology-dependent genetic compensation response (HDGCR) being the main pathway. Our further analysis suggested that MDA5 of M. miiuy and Gallus gallus, the homolog of RIG-I, can replace RIG-I in recognizing 5’ppp-RNA virus, which may lead to redundancy of RIG-I and loss from the species genome during evolution. Secondly, as an adversarial strategy, 5’ppp-RNA SCRV can utilize the m6A methylation mechanism to degrade MDA5 and weaken its antiviral immune ability, thus promoting its own replication and immune evasion. In summary, our study provides a snapshot into the interaction and coevolution between vertebrate and virus, offering valuable perspectives on the ecological and evolutionary factors that contribute to the diversity of the immune system.

An arms race between 5'ppp-RNA virus and its alternative recognition receptor MDA5 in RIG-I-lost teleost fish.

The incessant arms race between viruses and hosts has led to numerous evolutionary innovations that shape life's evolution. During this process, the interactions between viral receptors and viruses have garnered significant interest since viral receptors are cell surface proteins exploited by viruses to initiate infection. Our study sheds light on the arms race between the MDA5 receptor and 5'ppp-RNA virus in a lower vertebrate fish, Miichthys miiuy. Firstly, the frequent and independent loss events of RIG-I in vertebrates prompted us to search for alternative immune substitutes, with homology-dependent genetic compensation response (HDGCR) being the main pathway. Our further analysis suggested that MDA5 of M. miiuy and Gallus gallus, the homolog of RIG-I, can replace RIG-I in recognizing 5'ppp-RNA virus, which may lead to redundancy of RIG-I and loss from the species genome during evolution. Secondly, as an adversarial strategy, 5'ppp-RNA SCRV can utilize the m6A methylation mechanism to degrade MDA5 and weaken its antiviral immune ability, thus promoting its own replication and immune evasion. In summary, our study provides a snapshot into the interaction and coevolution between vertebrate and virus, offering valuable perspectives on the ecological and evolutionary factors that contribute to the diversity of the immune system.

Lower Devonian vertebrate microfossils from Turkey

A small sample of vertebrate fish scales, predominantly those of a thelodont agnathan, the turiniid Turinia sp. cf. T. nachoi, and a few from the acanthodian gnathostome Nostovicina laticristata, have been found in the Lower Devonian Güneyyaka Formation in the Ovacik slice of the Tahtalidağ Nappe north of Alanya (Antalya Unit) in the Antalya region, southwest Anatolia, southern Turkey. The area is considered to have been on the northern Gondwana margin at that time. The fish microfossils support a Lochkovian to possible early Pragian at youngest (Early Devonian) age for the limestone beds, and are amongst the oldest known Turkish vertebrate fossils. Yakut Göncüoglu [yigtjpc@gmail.com], Kafkas Sitesi 2481. Sok. No 65 Umitköy-Ankara, Turkey; Carole J. Burrow [carole.burrow@gmail.com], Queensland Museum Geosciences, 122 Gerler Road, Hendra Queensland 4011, Australia; Susan Turner [paleodeadfish@yahoo.com], Queensland Museum Geosciences, 122 Gerler Road, Hendra Queensland 4011, Australia; Philippe Janvier [philippe.janvier@mnhn.fr], Muséum national d’Histoire naturelle, 75005 Paris, France; M. Cemal Göncüoglu [mcgoncu@metu.edu.tr], Middle East Technical University (METU), Department of Geological Engineering, 06531 Ankara, Turkey.

CircYthdc2 generates polypeptides through two translation strategies to facilitate virus escape

It is known that about 10 circular RNAs (circRNAs) can encode functional polypeptides in higher mammals. However, it is not clear whether the functional polypeptides that can be translated by circRNAs are only the products of the evolution of higher animals, or also widely exist in other lower organisms. In addition, it is also unclear whether the two ways of translating polypeptides using IRES and m6A in the one circRNA are exclusive or coexistent. Here, we discovered a novel circRNA derived from the 3′-5′ RNA helicase Ythdc2 (Ythdc2) gene in lower vertebrate fish, namely circYthdc2, which can translate into a 170 amino acid polypeptide (Ythdc2-170aa) through IRES sequence or m6A modification, and is involved in antiviral immune of fish. Moreover, SCRV infection can promote circYthdc2 translate Ythdc2-170aa. Then, we found that both Ythdc2-170aa and Ythdc2 can promote the degradation of STING by promoting the ubiquitination modification of K11 and K48 link of STING, and weaken the host’s antiviral innate immunity. Notably, when circYthdc2 is abundant, Ythdc2 preferentially degrades circYthdc2 and no longer promotes the degradation of STING. Further studies have shown that circYthdc2 is highly conserved from lower vertebrates to higher mammals, and human circYthdc2 can also encode the same polypeptide and play a similar function to that of fish circYthdc2. This discovery confirms for the first time that the ability of circRNA to encode functional proteins is evolutionarily conserved, and finds that the ways of polypeptide translation by the same circRNA were diverse, which is of great significance for further elucidating the function and evolution of circRNAs in vertebrates.

An update review: several extraction methods for collagen isolation in vertebrate fish

Fish are vertebrate animals with a backbone that live in marine environments, presenting a potential source of collagen due to their high protein content. Collagen is a structural protein in the body's connective tissue, contributing 25 to 30% of the total body protein. Collagen sources in fish can be found in the skin, scales, and bones. The isolation of collagen from fish involves several stages, including separation and cleaning, size reduction, removal of non-collagenous components, collagen extraction, and precipitation. The extraction method utilized in collagen isolation impacts the quantity of collagen produced. The aim of this literature review is to identify extraction methods applicable for collagen isolation in vertebrate fish, serving as a reference for selecting extraction methods in future research. The updated review method involved collecting journal data from various literature sources, obtained from national and international journals discussing collagen extraction methods in vertebrate fish. Based on the update review, the isolation of collagen from vertebrate fish is carried out using several extraction methods, including acid soluble collagen extraction, pepsin soluble collagen, water soluble collagen, organic acid ultrasound-assisted, extrusion hydro extraction, deep eutectic solvent, and supercritical fluid extraction.

Deep Learning for Enhanced Marine Vision: Object Detection in Underwater Environments

This study leverages the Semantic Segmentation of Underwater Imagery (SUIM) dataset, encompassing over 1,500 meticulously annotated images that delineate eight distinct object categories. These categories encompass a diverse array, ranging from vertebrate fish and invertebrate reefs to aquatic vegetation, wreckage, human divers, robots, and the seafloor. The use of this dataset involves a methodical synthesis of data through extensive oceanic expeditions and collaborative experiments, featuring both human participants and robots. The research extends its scope to evaluating cutting-edge semantic segmentation techniques, employing established metrics to gauge their performance comprehensively. Additionally, we introduce a fully convolutional encoder-decoder model designed with a dual purpose: delivering competitive performance and computational efficiency. Notably, this model boasts a remarkable accuracy of 88%, underscoring its proficiency in underwater image segmentation. Furthermore, this model's integration within the autonomy pipeline of visually-guided underwater robots presents its tangible applicability. Its rapid end-to-end inference capability addresses the exigencies of real-time decision-making, vital for autonomous systems. This study elucidates the model's practical benefits across diverse applications like visual serving, saliency prediction, and intricate scene comprehension. Crucially, the utilization of the Enhanced Super-Resolution Generative Adversarial Network (ESRGAN) elevates image quality, enriching the foundation upon which our model's success rests. This research establishes a solid groundwork for future exploration in underwater robot vision by presenting the model and the benchmark dataset.

Genome-wide identification and characterization of tissue specific long non-coding RNAs and circular RNAs in common carp (Cyprinus carpio L.)

Cyprinus carpio is regarded as a substitute vertebrate fish model for zebrafish. A varied category of non-coding RNAs is comprised of long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs). These ncRNAs were once considered non-functional “junk DNA” but research now shows they play important roles in gene expression regulation, chromatin modification, and epigenetic regulation. The systemic tissue-specific research of the lncRNAs and circRNAs of C. carpio is yet unexplored. A total of 468 raw RNA-Seq dataset across 28 distinct tissues from different varieties of common carp retrieved from public domain were pre-processing, mapped and assembled for lncRNA identification/ classification using various bioinformatics tools. A total of 33,990 lncRNAs were identified along with revelation of 9 miRNAs having 19 unique lncRNAs acting as their precursors. Additionally, 2,837 miRNAs were found to target 4,782 distinct lncRNAs in the lncRNA-miRNA-mRNA interaction network analysis, which resulted in the involvement of 3,718 mRNAs in common carp. A total of 22,854 circRNAs were identified tissue-wise across all the 28 tissues. Moreover, the examination of the circRNA-miRNA-mRNA interaction network revealed that 15,731 circRNAs were targeted by 5,906 distinct miRNAs, which in turn targeted 4,524 mRNAs in common carp. Significant signaling pathways like necroptosis, NOD-like receptor signaling pathway, hypertrophic cardiomyopathy, small cell lung cancer, MAPK signaling pathway, etc. were identified using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes. The web resource of common carp ncRNAs, named CCncRNAdb and available at http://backlin.cabgrid.res.in/ccncrnadb/ gives a comprehensive information about common carp lncRNAs, circRNAs, and ceRNAs interactions, which can aid in investigating their functional roles for its management.

CircMIB2 therapy can effectively treat pathogenic infection by encoding a novel protein

The mRNA therapy is widely used in the treatment of diseases due to its efficient characteristics, and the COVID-19 vaccine is the application of mRNA therapy. However, due to the instability of mRNA, mRNA vaccines often need lots of modifications to ensure its stability. Recent research shows that circRNA with stable RNA structure can encode protein, which provides a new direction for mRNA therapy. Here, we discovered a novel circRNA (circMIB2) derived from E3 ubiquitin-protein ligase MIB2 (MIB2) gene in lower vertebrate fish, which can translate into a 134 amino acid protein (MIB2-134aa) through m6A modification, and is involved in innate immunity. MIB2-134aa is completely consistent with the amino acid sequence of the two domains of host gene MIB2 protein; host gene MIB2 can target TRAF6 through the two domains and inhibit the innate immune response by promoting the ubiquitination degradation of the K11-link of TRAF6, MIB2-134aa also targets TRAF6 through these same domains. Interestingly, MIB2-134aa greatly reduced the degradation of TRAF6 by its host gene MIB2. More importantly, we found that circRNA therapy of circMIB2 can significantly inhibit the colonization of Vibrio anguillarum in zebrafish, and it provides a new direction for the treatment of pathogenic diseases of fish.

Periphyton and benthivorous fish affect charophyte abundance and indicate hidden nutrient loading in oligo‐ and mesotrophic temperate hardwater lakes

Abstract Charophytes are a key group of submerged macrophytes in temperate hardwater lakes, but have declined or been replaced by angiosperms as a result of eutrophication for more than 100 years. At present, this process is continuing in many European lakes despite an overall reduced nutrient loading. In eutrophic lakes, light attenuation by periphyton is a major factor responsible for declining angiosperm abundance. For charophyte declines, the impact of benthivorous and herbivorous fish has been discussed often, yet periphyton shading has been largely neglected. In our study, we investigated 11 temperate oligo‐mesotrophic (total phosphorus [P] concentrations 9–22 μg/L) hardwater lakes along a gradient of charophyte abundances. Charophyte abundance was mapped using underwater cameras or scuba diving, and coverage was estimated in five classes. Periphyton biomass, nutrient stoichiometry and invertebrate grazer abundance were measured twice on artificial substrates exposed inside and outside fish exclosures for 4 weeks in July and August. Fish biomass was sampled once using multi‐mesh gill netting. We analysed the relationships between water chemistry (concentrations of nutrients and dissolved organic carbon), periphyton biomass and nutrient stoichiometry, periphytic invertebrate grazers and fish biomass to test (a) whether periphyton biomass was controlled bottom‐up by nutrient availability or top‐down by an omnivorous fish–invertebrate–grazer cascade and (b) whether charophyte abundance was affected by periphyton biomass, benthivorous and herbivorous fish. Multiple linear regressions revealed that charophyte abundance was significantly predicted by the biomasses of periphyton and benthivorous bream (Abramis brama L.), whereas herbivorous rudd (Scardinius erythrophthalmus L.) had no significant effect in the investigated lakes. Bream biomass and its proportion in the total fish biomass were linearly related to lake total P concentrations. Periphyton biomass in the tested lakes reached 0.1–21 g dry weight/m2 and primarily was controlled bottom‐up by P availability as indicated from stoichiometry and positive correlations with grazer abundance. Top‐down control was found in only three lakes, which had significantly lower periphyton biomass inside fish exclosures as compared to controls. Our data imply that periphyton shading and negative fish impacts on charophytes increase with P loading. Low charophyte abundances at moderate P concentrations in the lake water indicate a high sensitivity of charophytes and/or unnoticed nutrient loading due to nutrient retention by charophyte stands. Management measures thus must focus on reducing nutrient loading and/or benthivorous fish biomass at early stages of impact to preserve charophyte stands in oligo‐mesotrophic hardwater lakes.

Identification of in vivo induced antigens of the malacosporean parasite Tetracapsuloides bryosalmonae (Cnidaria) using in vivo induced antigen technology.

Tetracapsuloides bryosalmonae is a malacosporean endoparasite that causes proliferative kidney disease (PKD) in wild and farmed salmonids in Europe and North America. The life cycle of T. bryosalmonae completes between invertebrate bryozoan and vertebrate fish hosts. Inside the fish, virulence factors of T. bryosalmonae are induced during infection or interactions with host cells. T. bryosalmonae genes expressed in vivo are likely to be important in fish pathogenesis. Herein, we identify in vivo induced antigens of T. bryosalmonae during infection in brown trout (Salmo trutta) using in vivo induced antigen technology (IVIAT). Brown trout were exposed to the spores of T. bryosalmonae and were sampled at different time points. The pooled sera were first pre-adsorbed with antigens to remove false positive results. Subsequently, adsorbed sera were used to screen a T. bryosalmonae cDNA phage expression library. Immunoscreening analysis revealed 136 immunogenic T. bryosalmonae proteins induced in brown trout during parasite development. They are involved in signal transduction, transport, metabolism, ion-protein binding, protein folding, and also include hypothetical proteins, of so far unknown functions. The identified in vivo induced antigens will be useful in the understanding of T. bryosalmonae pathogenesis during infection in susceptible hosts. Some of the antigens found may have significant implications for the discovery of candidate molecules for the development of potential therapies and preventive measures against T. bryosalmonae in salmonids.

Light-induced algae retinal stress can deform fish spines

Algae are often used as live feed for aquatic animals and widely used in the aquaculture industry. Both algal cultivation and algal blooms can lead to algal cell aggregation. High-biomass algae will lead to the accumulation of toxic and harmful substances if they are present in algal cells, thus adversely affecting the environment or the food chain. Retinoids have been detected in algal cells, and retinoic acids and their derivatives are teratogenic in animals. However, whether retinal (RAL), a metabolite of β-carotene, is regulated by light and harmful to aquatic organisms has not been thoroughly investigated. This study focused on light-induced RAL accumulation in marine algae and its teratogenic effects in the algae-invertebrate-vertebrate food chain. The concentrations of RAL in two species of marine algae (Thalassiosira pseudonana and Tetraselmis subcordiformis), used as live feed in mariculture, were determined. Based on the differences in the accumulation of RAL in algae under different light environments, we explored retinol dehydrogenase (RDH) as the possible regulatory gene. The teratogenic effects of RAL on embryos and juveniles of marine teleost medaka (Oryzias melastigma) and brine shrimp (Artemia salina) and on food chain transmission characteristics were also explored. Our results suggest that continuous high and blue light exposure induced RDH expression, and further promoted RAL accumulation. This further amplifies the accumulation of RAL in the case of high biomass algal cultivation or algal blooms. High concentrations of RAL have teratogenic effects on vertebrate fish through the food chain due to the tolerance of invertebrates. This article could provide a warning about teratogenic effects on aquatic animals in aquaculture and algal bloom.

Triploid forms’ karyotypes of spined loaches from the genus Cobitis (Actinopterygii: Cypriniformes: Cobitidae) of the upper Dnieper and Western Dvina rivers: Analysis of the triploids’ origin

Unisexual forms of lower vertebrates (fish, amphibians, and reptiles) reproduced by parthenogenesis, gynogenesis, or hybridogenesis are represented by diploids, triploids, or tetraploids, whose origin is associated with interspecific hybridization. Among fish species, the highest variability of unisexual polyploids was found in the genus Cobitis. The structure of their genomes and putative parental species holds great interest for the investigation in association with questions about possible evolutionary success. In particular, it serves to elucidate the possible high colonization properties of a few polyploid forms, in contrast to the local history of rather numerous hybrid forms with a limited distribution. Therefore, the aim of this study was to describe the karyotype structure of two newly discovered triploid forms of the genus Cobitis, to analyze their origin and putative parental species. The karyotype structure of 182 spined loach individuals from the Western Dvina River and 91 individuals from the upper Dnieper River of the Smolensk District of Russia was studied. A total of 121 studied individuals from the Western Dvina comprised triploid females with a chromosome number 74 and karyotype consisting of 13 meta-, 39 submeta-, and 22 subtelo-acrocentric chromosomes. Among loaches collected in the upper Dnieper River, 42 triploid females were found with 74 chromosome number including 23 meta-, 26 submeta-, and 25 subtelo-acrocentric chromosomes. Other individuals from both localities were karyologically identified as Cobitis taenia Linnaeus, 1758 with 2n = 48. The triploid form of spined loaches of the Western Dvina River most likely arose as a result of the hybridization of Cobitis tanaitica Bǎcescu et Mayer, 1969 and C. taenia. The range of C. tanaitica, whose karyotype is characterized by an evolutionarily fixed Y-autosomal translocation, is limited to the rivers of the northern coast of the Black Sea. Therefore, hybridization probably happened in late Pleistocene in the Dnieper River system, where both parental species occur. The triploid form that arose here is unique for the Baltic Sea basin. Probably, it colonized the Western Dvina through the artificial Berezinskaya water system (Berezina Canal = Daugava–Dnieper Canal), but at the same time it was forced out of its area of origin by other triploid forms which are now widespread there. According to the karyotype structure, the triploid form, common for both the upper and lower reaches of the Dnieper, has a trihybrid origin, with probable hybridization of Cobitis elongatoides Bǎcescu et Mayer, 1969, C. tanaitica, and yet unidentified species Cobitis sp. Both studied triploid forms are parts of unisexual-bisexual complexes, in which their putative diploid maternal species (C. tanaitica and C. elongatoides) are absent, and the role of the host species involved in reproduction belongs to C. taenia.

Interactions and Stability of Gut Microbiota in Zebrafish Increase with Host Development.

ABSTRACTUnderstanding interactions within the gut microbiome and its stability are of critical importance for deciphering ecological issues within the gut ecosystem. Recent studies indicate that long-term instability of gut microbiota is associated with human diseases, and recovery of stability is helpful in the return to health. However, much less is known about such topics in fish, which encompass nearly half of all vertebrate diversity. Here, we examined the assembly and succession of gut microbiota in more than 550 zebrafish, and evaluated the variations of microbial interactions and stability across fish development from larva to adult using molecular ecological network analysis. We found that microbial interactions and stability in the fish gut ecosystem generally increased with host development. This could be attributed to the development of the zebrafish immune system, the increasing amount of space available for microbial colonization within the gut, and the greater stability of nutrients available for the colonized microbiota in adult zebrafish. Moreover, the potential keystone taxa, even those with relatively low abundances, played important roles in affecting the microbial interactions and stability. These findings indicate that regulating rare keystone taxa in adult fish may have great potential in gut microbial management to maintain gut ecosystem stability, which could also provide references for managing gut microbiota in humans and other animals.IMPORTANCE Understanding gut microbial stability and the underlying mechanisms is an important but largely ignored ecological issue in vertebrate fish. Here, using a zebrafish model and network analysis of the gut microbiota we found that microbial interactions and stability in the gut ecosystem increase with fish development. This finding has important implications for microbial management to maintain gut homeostasis and provide better gut ecosystem services for the host. First, future studies should always consider using fish of different age groups to gain a full understanding of gut microbial networks. Second, management of the keystone taxa, even those that are only present at a low abundance, during the adult stage may be a viable pathway to maintain gut ecosystem stability. This study greatly expands our current knowledge regarding gut ecosystem stability in terms of ecological networks affected by fish development, and also highlights potential directions for gut microbial management in humans and other animals.

Characterization of the Immune Response to Vibrio cholerae Infection in a Natural Host Model.

The gram-negative bacterium Vibrio cholerae causes the life-threatening diarrheal disease cholera, which is spread through the ingestion of contaminated food or water. Cholera epidemics occur largely in developing countries that lack proper infrastructure to treat sewage and provide clean water. Numerous vertebrate fish species have been found to be natural V. cholerae hosts. Based on these findings, zebrafish (Danio rerio) have been developed as a natural host model for V. cholerae. Diarrheal symptoms similar to those seen in humans are seen in zebrafish as early as 6 hours after exposure. Our understanding of basic zebrafish immunology is currently rudimentary, and no research has been done to date exploring the immune response of zebrafish to V. cholerae infection. In the present study, zebrafish were infected with either pandemic El Tor or non-pandemic, environmental V. cholerae strains and select immunological markers were assessed to determine cellular immunity and humoral immunity. Significant increases in the gene expression of two transcription factors, T-bet and GATA3, were observed in response to infection with both V. cholerae strains, as were levels of mucosal related antibodies. Additionally, the cytokine IL-13 was shown to be significantly elevated and paralleled the mucin output in zebrafish excretions, strengthening our knowledge of IL-13 induced mucin production in cholera. The data presented here further solidify the relevancy of the zebrafish model in studying V. cholerae, as well as expanding its utility in the field of cholera immunology.

MicroRNA-124 Promotes Singapore Grouper Iridovirus Replication and Negatively Regulates Innate Immune Response.

Viral infections seriously affect the health of organisms including humans. Now, more and more researchers believe that microRNAs (miRNAs), one of the members of the non-coding RNA family, play significant roles in cell biological function, disease occurrence, and immunotherapy. However, the roles of miRNAs in virus infection (entry and replication) and cellular immune response remain poorly understood, especially in low vertebrate fish. In this study, based on the established virus-cell infection model, Singapore grouper iridovirus (SGIV)-infected cells were used to explore the roles of miR-124 of Epinephelus coioides, an economically mariculture fish in southern China and Southeast Asia, in viral infection and host immune responses. The expression level of E. coioides miR-124 was significantly upregulated after SGIV infection; miR-124 cannot significantly affect the entry of SGIV, but the upregulated miR-124 could significantly promote the SGIV-induced cytopathic effects (CPEs), the viral titer, and the expressions of viral genes. The target genes of miR-124 were JNK3/p38α mitogen-activated protein kinase (MAPK). Overexpression of miR-124 could dramatically inhibit the activation of NF-κB/activating protein-1 (AP-1), the transcription of proinflammatory factors, caspase-9/3, and the cell apoptosis. And opposite results happen when the expression of miR-124 was inhibited. The results suggest that E. coioides miR-124 could promote viral replication and negatively regulate host immune response by targeting JNK3/p38α MAPK, which furthers our understanding of virus and host immune interactions.

First Report on Natural Infection of Nodavirus in an Echinodermata, Sea Cucumber (Apostichopus japonicas).

Cross-species transmission of emerging viruses happens occasionally due to epidemiological, biological, and ecological factors, and it has caused more concern recently. Covert mortality nodavirus (CMNV) was revealed to be a unique shrimp virus that could cross species barrier to infect vertebrate fish. In the present study, CMNV reverse transcription-nested PCR (RT-nPCR)-positive samples were identified from farmed sea cucumber (Apostichopus japonicas) in the CMNV host range investigation. The amplicons of RT-nPCR from sea cucumber were sequenced, and its sequences showed 100% identity with the RNA-dependent RNA polymerase gene of the original CMNV isolate. Histopathological analysis revealed pathologic changes, including karyopyknosis and vacuolation of the epithelial cells, in the sea cucumber intestinal tissue. The extensive positive hybridization signals with CMNV probe were shown in the damaged epithelial cells in the in situ hybridization assay. Meanwhile, transmission electron microscopy analysis revealed CMNV-like virus particles in the intestine epithelium. All the results indicated that the sea cucumber, an Echinodermata, is a new host of CMNV. This study supplied further evidence of the wide host range of CMNV and also reminded us to pay close attention to its potential risk to threaten different aquaculture animal species.

Some Drew Horses, and: Dash, and: The Family

Some Drew Horses, and: Dash, and: The Family Angela Sorby (bio) Some Drew Horses The two Kellys whocould draw horsesin third gradeunderstood balance.Their horses canteredacross construction paper.The Kellys loosedtheir small motorskills, and musclesrippled through their pencils.Their ponytails,shining in scrunchies,said Look At Me.No saddle, no rider.When we were older I'd envythe Kellys their beauty,and later still search Facebookto confirm they got fatin their forties,but when they were horsesI was their sky, their poppies,their prairie. On and onthey ran through me,with such authorityit was hard to believe—no, I still don't believe—we were children. [End Page 95] Dash My worst college job was typing triplicate insurance claims so badly I kept starting over, feeding sheets into an Underwood typewriter as neurotoxins rose from the Liquid Paper jar, obliterating most of the late eighties, plus I drank after work, so don't blame me, PJ, if I've forgotten how to fall in love—where to go, what to eat, who pays. After years of teaching I talk like I know what I'm saying, but, per npr's Shankar Vedantam, vertebrates—fish, birds, people—act with our primeval brainstems first. Only later do we dredge up words like love, whatever that means. Last night a raptor landed on my shoulder in a dream. Way way back in the twentieth century, Freudians would mansplain: you're ambivalent, you're afraid, but gone are the days of the wellangela [End Page 96] padded psychoanalytic interior. What's left? The spine holds what the mind drops: nodes, not sentences. Go above your nerve, wrote Dickinson, Queen of the Overthinkers, but when she fell for Judge Otis Lord, it hit her— the dash, the ecstatic erasure. The Family Before our divorce my exdealt books, so one yearour basement was suddenlyfull of a dead mob boss's library—torture manuals,philosophy, criminal law,opera librettos, and of course,Mario Puzo's The Godfather. Some volumes were heavilyannotated: How to Dominate Others,Stalin's Strategies. The boss,one Joey Balistrieri, spent his jail terms literallystudying how to be evil,marking key passages.If there's an evil gre, he passed— bribing cops, whacking rivals,but when I picture Joey in his cell,bent over Machiavelli's The Prince,his neck is smooth and vulnerable, [End Page 97] a swan's neck, as if evil misseda few nodes in back and relaxedinto—if not innocence,then curiosity. Now he's nowhere mail goes,but if I could send him a gentlebook (Charlotte's Web, maybe?)I'd inscribe the flyleaf Dear Uncle Joey,since whatever dnamakes us readersmakes us forever family. [End Page 98] Angela Sorby Angela Sorby is Professor of English and Director of the Graduate Program at Marquette University in Milwaukee. She's the author of three poetry books, Distance Learning (New Issues 1998), Bird Skin Coat (U of Wisconsin P 2009), and The Sleeve Waves (U of Wisconsin P 2014), plus a critical book, an anthology of children's poetry, and an edited collection on poetry and pedagogy. Her poetry has won a Midwest Book Award, the Brittingham Prize, the Felix Pollak Prize, the Lorine Niedecker Prize, Discovery/The Nation, and other honors. Copyright © 2021 University of Nebraska Press

The stage-specific long non-coding RNAs and mRNAs identification and analysis during early development of common carp, Cyprinus carpio

Cyprinus carpio is considered an alternative vertebrate fish model to zebrafish. However, systemic times-series research on the lncRNAs and mRNAs during early development of C. carpio has not been reported yet. This study provides the first long non-coding RNA (lncRNA)-mRNA expression profiles during six main early development stages (2 h post-fertilization hpf, 6 hpf, 12 hpf, 20 hpf, 64 hpf and 1 day post-hatching). A total of 51,979 lncRNAs were identified. We screened the top 10 abundance lncRNAs and mRNAs and stage-specific lncRNAs and mRNAs (specificity measure SPM > 0.9). We identified significant differentially expressed lncRNAs and mRNAs (|log2 (fold change)| ≥ 1 and false discovery rate FDR of <0.05). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis identified numerous signaling pathways. Additionally, the lncRNA-mRNA co-regulated network analysis of two lncRNAs (lncrps25 and malat1) and two mRNAs (mitf and troponin T) were investigated. Our results provide new insight into the role of lncRNAs and mRNAs, and would advance the understanding of lncRNA-mediated mechanisms in early development of fish.

The full-length mitochondrial genome of Tachysurus fulvidraco (Siluriformes: Bagridae) from Geum river in Korea

The full-length mitochondrial genome of the yellow catfish, Tachysurus fulvidraco was analyzed by the primer walking method. Its assembled mitochondrial genome was found to be 16,527 bp, consisting of 37 genes (13 protein-coding genes, 22 tRNA gens, and 2 rRNA gens). The gene content and order of T. fulvidraco were congruent with those of typical vertebrate fishes. In the phylogenetic tree, it showed the closet relationship to the another conspecific specimen from China and Pseudobagrus koreanus and well separated from the other species in the family Bagridae.

Giraffe taxonomy, geographic distribution and conservation

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