RESUMO
The blue mussel Mytilus chilensis is an endemic and key socioeconomic species inhabiting the southern coast of Chile. This bivalve species supports a booming aquaculture industry, which entirely relies on artificially collected seeds from natural beds that are translocated to diverse physical-chemical ocean farming conditions. Furthermore, mussel production is threatened by a broad range of microorganisms, pollution, and environmental stressors that eventually impact its survival and growth. Herein, understanding the genomic basis of the local adaption is pivotal to developing sustainable shellfish aquaculture. We present a high-quality reference genome of M. chilensis, which is the first chromosome-level genome for a Mytilidae member in South America. The assembled genome size was 1.93 Gb, with a contig N50 of 134 Mb. Through Hi-C proximity ligation, 11,868 contigs were clustered, ordered, and assembled into 14 chromosomes in congruence with the karyological evidence. The M. chilensis genome comprises 34,530 genes and 4795 non-coding RNAs. A total of 57% of the genome contains repetitive sequences with predominancy of LTR-retrotransposons and unknown elements. Comparative genome analysis of M. chilensis and M. coruscus was conducted, revealing genic rearrangements distributed into the whole genome. Notably, transposable Steamer-like elements associated with horizontal transmissible cancer were explored in reference genomes, suggesting putative relationships at the chromosome level in Bivalvia. Genome expression analysis was also conducted, showing putative genomic differences between two ecologically different mussel populations. The evidence suggests that local genome adaptation and physiological plasticity can be analyzed to develop sustainable mussel production. The genome of M. chilensis provides pivotal molecular knowledge for the Mytilus complex.
Assuntos
Mytilus edulis , Mytilus , Animais , Mytilus/genética , Chile , Aquicultura , Cromossomos/genéticaRESUMO
PIM kinases are a family of serine/threonine protein kinases that potentiate the progression of the cell cycle and inhibit apoptosis. Because of this, they are considered to be proto-oncogenes, and they represent an interesting target for the development of anticancer drugs. In mammals, three PIM kinases exist (PIM-1, PIM-2 and PIM-3), and different inhibitors have been developed to block their activity. In addition to their involvement in cancer, some publications have reported that the PIM kinases have pro-viral activity, and different mechanisms where PIM kinases favour viral infections have been proposed. Zebrafish possess more than 300 Pim kinase members in their genome, and by using RNA-Seq analysis, we found a high number of Pim kinase genes that were significantly induced after infection with spring viraemia of carp virus (SVCV). Moreover, analysis of the miRNAs modulated by this infection revealed that some of them could be involved in the post-transcriptional regulation of Pim kinase abundance. To elucidate the potential role of the 16 overexpressed Pim kinases in the infectivity of SVCV, we used three different pan-PIM kinase inhibitors (SGI-1776, INCB053914 and AZD1208), and different experiments were conducted both in vitro and in vivo. We observed that the PIM kinase inhibitors had a protective effect against SVCV, indicating that, similar to what is observed in mammals, PIM kinases are beneficial for the virus in zebrafish. Moreover, zebrafish Pim kinases seem to facilitate viral entry into the host cells because when ZF4 cells were pre-incubated with the virus and then were treated with the inhibitors, the protective effect of the inhibitors was abrogated. Although more investigation is necessary, these results show that pan-PIM kinase inhibitors could serve as a useful treatment for preventing the spread of viral diseases.
Assuntos
Rim/enzimologia , Proteínas Proto-Oncogênicas c-pim-1/genética , Infecções por Rhabdoviridae/veterinária , Internalização do Vírus/efeitos dos fármacos , Peixe-Zebra/virologia , Animais , Apoptose , Compostos de Bifenilo/farmacologia , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Imidazóis/farmacologia , Rim/virologia , Poli I-C/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-pim-1/antagonistas & inibidores , Piridazinas/farmacologia , RNA-Seq , Rhabdoviridae , Tiazolidinas/farmacologia , Peixe-Zebra/anatomia & histologiaRESUMO
Although the modulation of immune-related genes after viral infection has been widely described in vertebrates, the potential implications of non-coding RNAs (ncRNAs), especially long non-coding RNAs (lncRNAs), in immunity are still a nascent research field. The model species zebrafish could serve as a useful organism for studying the functionality of lncRNAs due to the numerous advantages of this teleost, including the existence of numerous mutant lines. In this work, we conducted a whole-transcriptome analysis of wild-type (WT) and heterozygous rag1 mutant (rag1+/-) zebrafish after infection with the pathogen spring viraemia of carp virus (SVCV). WT and rag1+/- zebrafish were infected with SVCV for 24 h. Kidney samples were sampled from infected and uninfected fish for transcriptome sequencing. From a total of 198,540 contigs, 12,165 putative lncRNAs were identified in zebrafish. Most of the putative lncRNAs were shared by the two zebrafish lines. However, by comparing the lncRNA profiles induced after SVCV infection in WT and rag1+/- fish, most of the lncRNAs that were significantly induced after viral challenge were exclusive to each line, reflecting a highly differential response to the virus. Analysis of the neighboring genes of lncRNAs that were exclusively modulated in WT revealed high representation of metabolism-related terms, whereas those from rag1+/- fish showed enrichment in terms related to the adaptive immune response, among others. On the other hand, genes involved in numerous antiviral processes surrounded commonly modulated lncRNAs, as expected. These results clearly indicate that after SVCV infection in zebrafish, the expression of an array of lncRNAs with functions in different aspects of immunity is induced.
Assuntos
Proteínas de Homeodomínio/genética , RNA Longo não Codificante/genética , Transcriptoma , Viremia/imunologia , Animais , Heterozigoto , Rim/metabolismo , Rim/virologia , Mutação , RNA Longo não Codificante/metabolismo , Rhabdoviridae/patogenicidade , Viremia/genética , Viremia/virologia , Peixe-ZebraRESUMO
Interferon-gamma (IFN-Ï) is probably one of the most relevant cytokines orchestrating the immune response in vertebrates. Although the activities mediated by this molecule are well known in mammals, several aspects of the IFN-Ï system in teleosts remain a riddle to scientists. Numerous studies support a potentially similar role of the fish IFN-Ï signalling pathway in some well-described immunological processes induced by this cytokine in mammals. Nevertheless, the existence in some teleost species of duplicated ifng genes and an additional gene derived from ifng known as interferon-γ-related (ifngrel), among other things, raises new interesting questions about the mode of action of these various molecules in fish. Moreover, certain IFN-Ï-mediated activities recently observed in mammals are still fully unknown in fish. Another attractive but mainly unexplored curious property of IFN-Ï in vertebrates is its potential dual role depending on the type of pathogen. In addition, some aspects mediated by this molecule could favour the resolution of a bacterial infection but be harmful in the context of a viral disease, and vice versa. This review collects old and new aspects of IFN-Ï research in teleosts and discusses new questions and pathways of investigation based on recent discoveries in mammals.
Assuntos
Proteínas de Peixes/genética , Peixes/genética , Interferon gama/genética , Animais , Proteínas de Peixes/imunologia , Proteínas de Peixes/metabolismo , Peixes/imunologia , Interferon gama/imunologia , Interferon gama/metabolismoRESUMO
MicroRNAs are non-coding RNA that plays a crucial role in post-transcriptional regulation and immune system regulation. On other hand, sea lice are prevalent parasites that affect salmon farming, generating different degrees of immune suppression depending on the salmon and sea louse species. Caligus rogercresseyi for example, which affects the salmon industry in Chile, decreases Th1 response, macrophage activation, TLR-mediated response and iron regulation in infected fish. In this study, we explore Atlantic salmon miRNome during infestation by C. rogercresseyi. Using small RNA sequencing, we annotated 1718 miRNAs for skin and head kidney from infected Atlantic salmon. The most abundant families identified were mir-10, mir-21, mir-30, mir-181 and let7. Significant differences were found between tissue, with 1404 annotated miRNA in head kidney and 529 in skin. Differential analysis of transcript expression indicated that at an early stage of infestation miRNA expression was higher in head kidney than in skin tissue, revealing tissue-specific expression patterns. In parallel, miRNA target prediction using 3'UTRs from highly regulated immune-related genes and iron metabolism showed that mir-140-4 and mir-181a-2-5 modulate the expression of TLR22 and Aminolevulinic acid synthase, respectively. This study contributes knowledge about the immune response of Atlantic salmon during infestation with sea lice.
Assuntos
Copépodes/imunologia , Doenças dos Peixes/imunologia , Rim Cefálico/fisiologia , MicroRNAs/genética , Doenças Parasitárias em Animais/imunologia , Salmo salar/imunologia , Pele/patologia , Animais , Chile , Biologia Computacional , Ectoparasitoses , Rim Cefálico/parasitologia , Imunidade/genética , Imunomodulação , Ferro/metabolismo , Especificidade de Órgãos , Salmo salar/parasitologia , Análise de Sequência de RNA , Pele/parasitologia , TranscriptomaRESUMO
Various hemocyte cell types have been described in invertebrates, but for most species a functional characterization of different hemocyte cell types is still lacking. In order to characterize some immunological properties of mussel (Mytilus galloprovincialis) hemocytes, cells were separated by flow cytometry and their capacity for phagocytosis, production of reactive oxygen species (ROS), and production of nitric oxide (NO), was examined. Phosphatidylinositol 3-kinase (PI 3-K), protein kinase C (PKC), and extracellular signal-regulated kinase (ERK) inhibitors were also used to biochemically characterize these cell responses. Four morphologically distinct subpopulations, designated R1-R4, were detected. R1, R2, and R3 cells presented different levels of phagocytosis towards zymosan, latex beads, and two bacteria species. Similarly, R1 to R3, but not R4, cells produced ROS, while all subpopulations produced NO, in response to zymosan. Internalization of all phagocytic targets was blocked by PI 3-K inhibition. In addition, internalization of latex particles, but not of bacteria, was partially blocked by PKC or ERK inhibition. Interestingly, phagocytosis of zymosan was impaired by PKC, or ERK inhibitors, only in R2 cells. Zymosan-induced ROS production was blocked by PI 3-K inhibition, but not by PKC, or ERK inhibition. In addition, zymosan-stimulated NO production was affected by PI 3-K inhibition in R1 and R2, but not in R3 or R4 cells. NO production in all cell types was unaffected by PKC inhibition, but ERK inhibition blocked it in R2 cells. These data reveal the existence of profound functional and biochemical differences in mussel hemocytes and indicate that M. galloprovincialis hemocytes are specialized cells fulfilling specific tasks in the context of host defense.
Assuntos
MAP Quinases Reguladas por Sinal Extracelular/imunologia , Hemócitos/imunologia , Mytilus/imunologia , Fosfatidilinositol 3-Quinases/imunologia , Proteína Quinase C/imunologia , Animais , Separação Celular , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Citometria de Fluxo , Hemócitos/citologia , Hemócitos/enzimologia , Imunidade Inata , Mytilus/enzimologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteína Quinase C/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Explosão Respiratória/imunologia , Transdução de Sinais/imunologia , Zimosan/metabolismoRESUMO
The cloning and sequencing of the small subunit (SSU) ribosomal DNA gene from Kudoa rosenbuschi (myxosporean species associated with post-mortem myoliquefaction process in the Argentinean hake Merluccius hubbsi) is reported. The SSU rDNA was found to contain 1740 bp with a single polymorphic site with either a C or T at position 221. The sequence data obtained in this study and those known sequences of Kudoa species deposited in the GenBank were all analyzed to construct a phylogenetic tree. Nucleotide sequences showed the highest degree of identity with K. funduli, followed by K. miniauriculata, K. clupeidae and K. dianae. Phylogenetic analysis placed K. rosenbuschi in the same branch of K. clupeidae and K. funduli, and showed it to be closely related to K. dianae, K. paniformis and K. miniauriculata.