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1.
Mar Pollut Bull ; 200: 116112, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38320442

RESUMO

Rapidly increasing concentration of carbon dioxide (CO2) in the atmosphere not only results in global warming, but also drives increasing seawater acidification. Infaunal bivalves play critical roles in benthic-pelagic coupling, but little is known about their behavioral responses to compound climate events. Here, we tested how heatwaves and acidification affected the behavior of Manila clams (Ruditapes philippinarum). Under acidified conditions, the clams remained capable of burrowing into sediments. Yet, when heatwaves attacked, significant decreases in burrowing ability occurred. Following two consecutive events of heatwaves, the clams exhibited rapid behavioral acclimation. The present study showed that the behavior of R. philippinarum is more sensitive to heatwaves than acidification. Given that the behavior can act as an early and sensitive indicator of the fitness of intertidal bivalves, whether, and to what extent, behavioral acclimation can persist under scenarios of intensifying heatwaves in the context of ocean acidification deserve further investigations.


Assuntos
Bivalves , Clima Extremo , Animais , Água do Mar , Concentração de Íons de Hidrogênio , Bivalves/fisiologia , Clima
2.
Artigo em Inglês | MEDLINE | ID: mdl-38246111

RESUMO

Salinity, a key limiting factor, affects the distribution and survival of marine species. The Hong Kong oyster (Crassostrea hongkongensis), a euryhaline species found along the coast of the South China Sea, has become a major aquaculture bivalve species. To determine the molecular mechanism by which oysters respond to coastal waters with varying salinity levels, we used RNA-seq to sequence the gill samples of oysters exposed to normal (25 ‰, S25), low (5 ‰, S5) and high (35 ‰, S35) salinity conditions for one month. The results revealed different expression transcriptome levels among oysters living under low and high salinity conditions. Using high-throughput sequencing, we identified 811 up-regulated genes and 769 down-regulated genes. As determined by KEGG pathway mapping, the differentially expressed genes (DEGs) were significantly enriched in the prion diseases, histidine metabolism, arginine and proline metabolism, and beta-alanine metabolism pathways in both the S5 vs. S25 and S35 vs. S25 group comparison. Several DEGs including heat shock 70 kDa protein 12B-like, poly (ADP-ribose) polymerase (PARP), and tripartite motif-containing protein 2 (TRIM2), and low-density lipoprotein receptor-like, as well as KEGG pathways, including arginine and proline metabolism, apoptosis, PPAR signaling pathway, the thyroid hormone signaling pathway, were concerning response to salinity stress. Additionally, eight DEGs involved in salinity adaptation were selected for RT-qPCR validation, and the results confirmed the credibility of the transcriptome sequencing data. Overall, we designed a one-month, medium-term experiment to examine the responses of C. hongkongensis exposed to different levels of salinity stress and performed transcriptome analysis using high-throughput sequencing. Our results enhance current understanding of the molecular mechanisms of salinity stress responses in C. hongkongensis and provided insights into the osmotic biology of oysters.


Assuntos
Crassostrea , Animais , Crassostrea/metabolismo , Transcriptoma , Estresse Salino , Arginina/genética , Arginina/metabolismo , Prolina/genética , Prolina/metabolismo , Salinidade
3.
Genomics ; 116(1): 110757, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38061482

RESUMO

To understand the environmental adaptations among sessile bivalves lacking adaptive immunity, a series of analyses were conducted, with special emphasis on the widely distributed C. ariakensis. Employing Pacbio sequencing and Hi-C technologies, whole genome for each of a C. ariakensis (southern China) and C. hongkongensis individual was generated, with the contig N50 reaching 6.2 and 13.0 Mb, respectively. Each genome harbored over 30,000 protein-coding genes, with approximately half of each genome consisting of repeats. Genome alignment suggested possible introgression between C. gigas and C. ariakensis (northern China), and re-sequencing data corroborated this result and indicated significant gene flow between C. gigas and C. ariakensis. These introgressed candidates, well-represented by genes related to immunity and osmotic pressure, may be associated with environmental stresses. Gene family dynamics modeling suggested immune-related genes were well represented among the expanded genes in C. ariakensis. These outcomes could be attributed to the spread of C. ariakensis.


Assuntos
Crassostrea , Animais , Crassostrea/genética , Sequenciamento Completo do Genoma , China
4.
Mar Environ Res ; 187: 105948, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36931046

RESUMO

The South American mussel, Mytella strigata, is a highly invasive fouling species of great concern along intertidal shores in East and Southeast Asia, posing serious threats to native biodiversity and ecosystems. Intertidal areas, being increasingly attacked by heatwaves over the last decade, are among the most thermally challenging habitats, yet the fate of this highly invasive mussel under scenarios of hotter heatwaves remains unknown. Here, we investigated how M. strigata responded to intensifying heatwaves frequently occurring in the South China Sea. Over 97% of individuals survived the five-day-lasting heatwaves, suggesting their high ability to cope with short-term heatwaves. Virtually unaffected clearance rate and absorption efficiency throughout the course of heatwaves indicate the maintenance of energy acquisition, and significantly decreased respiration rate implies the depression of energy metabolism, generating significant decreases in the O:N ratio when heatwaves occurred. Scope for growth of heatwaves-stressed mussels significantly decreased during initial exposure and then increased over time. These findings indicate the remarkable ability of M. strigata to cope with heatwaves recorded in its invasive habitats and call the attention for the rapid spread of this highly invasive fouling species in the context of climate change.


Assuntos
Ecossistema , Espécies Introduzidas , Mytilidae , Animais , Humanos , Mudança Climática , Metabolismo Energético , Temperatura Alta , Adaptação Fisiológica
5.
Artigo em Inglês | MEDLINE | ID: mdl-35303535

RESUMO

Horseshoe crabs are marine chelicerates that have existed on Earth for about 450 million years, and they are often used as an experimental model for studying marine invertebrate embryology. In this study, we performed transcriptome gene expression profiling of four continuous embryonic stages (Stages 18-21) and first instar larvae of Tachypleus tridentatus. A mean of 50,742,995 high-quality clean reads was obtained from each library. We then conducted weighted gene co-expression network analysis (WGCNA) for 13,698 genes with fragments per kilobase of exon per million mapped fragments values >5. We identified 17 modules, six of which likely play critical roles in development. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis of differentially expressed genes was performed on the biologically significant modules. We found that several pathways, such as hedgehog signaling pathway, VEGF signaling pathway, dorso-ventral axis formation, may be involved in the embryonic development process of T. tridentatus. We also identified hub genes that were highly connected in the six critical modules. This is the first study to apply WGCNA to horseshoe crabs to identify hub genes that may play critical roles in development, and our results provide new insight into the mechanisms underlying early development in horseshoe crabs.


Assuntos
Redes Reguladoras de Genes , Caranguejos Ferradura , Animais , Perfilação da Expressão Gênica , Genoma , Proteínas Hedgehog/genética , Caranguejos Ferradura/genética , Larva/genética
6.
Sensors (Basel) ; 22(4)2022 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-35214537

RESUMO

Impacted by global warming, the global sea surface temperature (SST) has increased, exerting profound effects on local climate and marine ecosystems. So far, investigators have focused on the short-term forecast of a small or medium-sized area of the ocean. It is still an important challenge to obtain accurate large-scale and long-term SST predictions. In this study, we used the reanalysis data sets provided by the National Centers for Environmental Prediction based on the Internet of Things technology and temporal convolutional network (TCN) to predict the monthly SSTs of the Indian Ocean from 2014 to 2018. The results yielded two points: Firstly, the TCN model can accurately predict long-term SSTs. In this paper, we used the Pearson correlation coefficient (hereafter this will be abbreviated as "correlation") to measure TCN model performance. The correlation coefficient between the predicted and true values was 88.23%. Secondly, compared with the CFSv2 model of the American National Oceanic and Atmospheric Administration (NOAA), the TCN model had a longer prediction time and produced better results. In short, TCN can accurately predict the long-term SST and provide a basis for studying large oceanic physical phenomena.


Assuntos
Ecossistema , Internet das Coisas , Clima , Oceano Índico , Temperatura
7.
Front Microbiol ; 11: 1714, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32849361

RESUMO

Rab GTPases play an important role in vesicle-mediated membrane trafficking in eukaryotes. Previous studies have demonstrated that deletion of RAB5/VPS21 reduces endocytosis and virulence of fungal phytopathogens in their host plants. However, Rab5 GTPase cycle regulators have not been characterized in Fusarium graminearum, the causal agent of Fusarium head blight (FHB) or head scab disease in cereal crops. In this study, we have identified and characterized a Rab5 guanine nucleotide exchange factor (GEF), the Vps9 homolog FgVps9, in F. graminearum. Yeast two hybrid (Y2H) assays have shown that FgVps9 specifically interacts with the guanosine diphosphate (GDP)-bound (inactive) forms of FgRab51 and FgRab52, the Rab5 isoforms in F. graminearum. Deletion of FgVPS9 shows impaired fungal growth and conidiation. Pathogenicity assays indicate that deletion of FgVPS9 can significantly decrease the virulence of F. graminearum in wheat. Cytological analyses have indicated that FgVps9 colocalizes with FgRab51 and FgRab52 on early endosomes and regulates endocytosis and autophagy processes. Gene expression and cytological examination have shown that FgVps9 and FgRab51 or FgRab52 function in concert to control deoxynivalenol (DON) biosynthesis by regulating the expression of trichothecene biosynthesis-related genes and toxisome biogenesis. Taken together, FgVps9 functions as a GEF for FgRab51 and FgRab52 to regulate endocytosis, which, as a basic cellular function, has significant impact on the vegetative growth, asexual development, autophagy, DON production, and plant infection in F. graminearum.

8.
Mol Ecol Resour ; 20(4): 980-994, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32198971

RESUMO

Crassostrea hongkongensis is a popular and important native oyster species that is cultured mainly along the coast of the South China Sea. However, the absence of a reference genome has restricted genetic studies and the development of molecular breeding schemes for this species. Here, we combined PacBio and 10 × Genomics technologies to create a C. hongkongensis genome assembly, which has a size of 610 Mb, and is close to that estimated by flow cytometry (~650 Mb). Contig and scaffold N50 are 2.57 and 4.99 Mb, respectively, and BUSCO analysis indicates that 95.8% of metazoan conserved genes are completely represented. Using a high-density linkage map of its closest related species, C. gigas, a total of 521 Mb (85.4%) was anchored to 10 haploid chromosomes. Comparative genomic analyses with other molluscs reveal that several immune- or stress response-related genes extensively expanded in bivalves by tandem duplication, including C1q, Toll-like receptors and Hsp70, which are associated with their adaptation to filter-feeding and sessile lifestyles in shallow sea and/or deep-sea ecosystems. Through transcriptome sequencing, potential genes and pathways related to sex determination and gonad development were identified. The genome and transcriptome of C. hongkongensis provide valuable resources for future molecular studies, genetic improvement and genome-assisted breeding of oysters.


Assuntos
Cromossomos/genética , Crassostrea/genética , Genoma/genética , Adaptação Fisiológica/genética , Animais , China , Mapeamento Cromossômico/métodos , Ecossistema , Genômica/métodos , Análise de Sequência de DNA , Transcriptoma/genética
9.
J Colloid Interface Sci ; 562: 578-588, 2020 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-31787251

RESUMO

Here, a novel Mg/Al-layered double oxide (MgAl-LDO) with a flower-like architecture was synthesized through facile green co-precipitation and calcination methods for phosphate separation and recycle from wastewater. The as-prepared MgAl-LDO demonstrated high specific surface area of 200.17 m2/g based on its 3D hierarchical flower-like structure. The phosphate adsorption was well conformed to Pseudo-second-order kinetic model and Langmuir model, suggesting a homogeneous monolayer chemisorption with a maximum adsorption capability of 103.61 mg P/g. The existence of Cl-, NO3- ions did not interfere with phosphate adsorption, while high concentration SO42- and CO32- affected the phosphate adsorption. In addition, adsorption mechanism analysis revealed that high-efficiency phosphate capture by MgAl-LDO was mainly due to the electrostatic adsorption, surface inner-sphere complexation, ligand exchange and precipitation combined process. Remarkably, the phosphate adsorbed MgAl-LDO (P-LDO) can be employed as synergistic flame retardant to improve the flame retardancy of paper.

10.
Artigo em Inglês | MEDLINE | ID: mdl-31325756

RESUMO

Crassostrea hongkongensis is one of the three most-commonly cultivated oyster species in China. Although microRNAs (miRNAs) expression in the gonads have been widely investigated, few studies of miRNAs in mollusk gonads are available, particularly in oyster. In the present study, we analyzed the miRNAs expressed in the ovaries and testes of C. hongkongensis. We obtained 14,166,409 and 15,133,900 raw reads from the ovaries and testes, respectively, yielding 13,634,997 (ovarian) and 14,494,149 (testicular) 18-35-nt sequences. We mapped these sequences to the C. hongkongensis genome reference sequence, and identified 8,771,717 (ovarian) and 9,926,014 (testicular) sequences corresponding to miRNAs in the Rfam database. After blasting the miRNA sequences against the miRBase database, we identified 50 known mature miRNAs and 53 novel miRNAs. Of these, 27 miRNAs were significantly upregulated in ovaries as compared to the testes, and 43 miRNAs were significantly upregulated in the testes as compared to the ovaries. To validate the differential expression results generated by Illumina sequencing, we used RT-real-time quantitative PCR (RT-qPCR) to characterize the expression patterns of the six most differently expressed miRNAs (lgi-miR-1990, lgi-miR-1986, lgi-miR-263b, lgi-miR-279, lgi-miR-1992, and novel_98) as well as two miRNAs associated with gonad development (lgi-miR-29 and lgi-miR-8). Most of the RT-qPCR miRNA expression patterns were similar to those recovered by high-throughput sequencing with the exceptions of novel_98 and lgi-miR-1992. Gene Ontology (GO) annotations indicated that the multi-organism cellular process GO category was enriched with the target genes of the differentially expressed miRNAs. Additionally, the target genes were enriched in several KEGG pathways, including the ECM-receptor interaction, galactose metabolism, phagosome, and notch signaling pathway. These pathways are involved in gonadal differentiation and the maintenance of gonad function. This identification and characterization of the miRNAs differentially expressed between the ovaries and testes of C. hongkongensis will increase our understanding of the role of miRNAs in gonad differentiation in the oyster.


Assuntos
Crassostrea/genética , Gônadas/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala/métodos , MicroRNAs/genética , Animais , Feminino , Perfilação da Expressão Gênica , Masculino
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