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The feeding rhythm is one of the key factors determining the success of artificial breeding of S. paramamosain. To understand the feeding rhythm of the different zoea larva developmental stages of S. paramamosain, the feeding rate, digestive enzyme activity, and expression of metabolism-related genes were investigated in the present study. The results showed that the S. paramamosain feeding rate has strong diurnal feeding rhythm, being significantly higher at 10:00–14:00 from stages ZI to ZIV. While the feeding rate peaked at 14:00 on Days 10 and 11, the peak shifted to 18:00 on Day 12. The activity of digestive enzymes amylase, pepsin and lipase decreased at night but increased in the daytime, showing a single-phase rhythm similar to that of the feeding rate, suggesting that the digestive enzyme activity was closely associated with the feeding rate during the larval development. Compared to pepsin and lipase, the activity of amylase was the most consistent with feeding rate. In particular, amylase activity peaked at 18:00 on Day 12. Due to its synchronicity with feeding activity, the activity of amylase could provide a potential reference for determining the best feeding time during zoea stages in S. paramamosain breeding. Moreover, the relative mRNA expression of metabolism-related genes SpCHH and SpFAS at most tested points was lower from 10:00 to 14:00, but higher at 18:00 to 6:00 of the next day. On the other hand, the expression patterns of SpHSL and SpTryp were converse to those of SpCHH and SpFAS. Our findings revealed that the S. paramamosain zoea has an obvious feeding rhythm, and the most suitable feeding time was 10:00–18:00 depending on different stages. The feeding rhythm is a critical aspect in aquaculture, influencing a series of physiological functions in aquatic animals. This study provides insights into the feeding rhythm during the zoea development of S. paramamosain, making a significant contribution to optimizing feeding strategy, improving aquafeed utilization, and reducing the impact of residual feed on water environment.

The giant freshwater prawn (Macrobrachium rosenbergii) is a commercially cultured species in China. A sex chromosome-specific marker is crucial for sex identification and distinguishing sex chromosomes. Here, based on the results of reduced-representation genome sequencing and genome survey of M. rosenbergii, we identified steady sex-linked markers. Further nucleotide alignment analysis revealed 83.42% nucleotide similarity between the amplified W- and Z-chromosome fragments. qPCR confirmed that Z chromosome-specific fragments were present in males approximately twice as often compared to females. Similarly, the W chromosome-specific fragments were present in super females approximately twice as often compared to females. Our findings elucidate the ZW/ZZ sex determination type and contribute to exploring sex-related or sex-determining genes present on the sex chromosomes of M. rosenbergii.

【Objective】Doublesex, a member of the DMRT gene family, plays a key role in controlling sex-specific differentiation. To clone the Open Reading Frame (ORF) of Macrobrachium rosenbergii Doublesex (MrDsx) gene, construct the recombinant plasmid and induce its expression, purify and obtain the recombinant protein MrDsx, will provides basic information for further study of MrDsx function.【Method】Based on the ORF sequence of MrDsx, the recombinant plasmid pET-32a-MrDsx was obtained by ligating the specific PCR product with the expression vector pET-32a (+). The recombinant plasmid pET-32a-MrDsx was transformed into the competent cells of Escherichia coli BL21 (DE3) to construct the prokaryotic expression cells of MrDsx. The isopropyl-beta-D-thiogalactoside (IPTG) was used to induce the expression of positive transformed cells, and the induced recombinant protein was detected by SDS-PAGE, Western blot and mass spectrometry analysis.【Result】Using the gonad cDNA as template, a single DNA band with the size of about 660 bp was obtained by the specific PCR primers of MrDsx. And the MrDsx ORF sequence was confirmed by sequencing. The recombinant protein MrDsx could be obtained from the transformed competent cells after induction by IPTG at 37℃ for 4 h. When the final concentration of IPTG was 0.1-0.5 mmol/L, the expression level of recombinant protein MrDsx reached its peak. Soluble analysis showed that the recombinant protein MrDsx was mainly expressed in the form of inclusion bodies. After solubilization with 8 mol/L urea, Ni purification, and dialysis renaturation, a single band was detected at the relative molecular weight of 55 kD by SDS-PAGE and Western blot, indicating that the recombinant protein MrDsx could be specifically recognized by His-tag mouse monoclonal antibody. The results of mass spectrometry analysis showed that the fragmented peptide was consistent with the theoretical amino acid sequence, and the matching degree was 100%.【Conclusion】The recombinant plasmid pET-32a-MrDsx was successfully obtained by prokaryotic expression of MrDsx. High purity active MrDsx protein can be obtained by the dissolution, purification and renaturation. This study provides a preliminary basis for the subsequent study of MrDsx gene function, screening of interacting proteins and elucidation of sex regulation mechanisms in M. rosenbergii.

Abstract In recent years, with the widespread use of TiO2–GO nanocomposite in industry, especially in the remediation of water environments, its toxic effects on aquatic organisms have received increasing attention. As molting is extremely important for crustaceans in their growth, in this study, we cloned the full-length cDNA sequences of two key genes related to molting, nuclear hormone receptor E75 (E75) and nuclear hormone receptor HR3 (HR3), in Macrobrachium rosenbergii, examined the gene expression profile, and investigated their toxicological effects on crustacean molting through nanomaterial exposure. The amino acid sequences for E75 and HR3 were respectively determined to encode 1138 and 363 acid residues. Sequence analysis showed that both E75 and HR3 contain a HOLI domain, with the E75 of M. rosenbergii being more closely related to the E75 of Palaemon carinicauda. These two genes were expressed at the highest levels in muscle, followed by hepatopancreas. The results showed that the expressions of E75 and HR3 in hepatopancreas and muscle tissues were significantly decreased after exposure to 0.1 mg/L of TiO2–GO composite nanoparticles (P

Dietary intake is an essential source of energy and nutrients, and plays an irreplaceable role in the breeding of S. paramamosain seedlings. In this study, live Artemia nauplii (LA), compound feeds (CF), frozen copepods (FC) and frozen adult Artemia (FA) were utilized as feed during the megalopa stage. To determine the impact that diet has on the metabolism of crablets that underwent metamorphosis from the megalopa stage, analyses of both metabolomics and fatty acid content were conducted. In the LC-MS-based metabolomics analysis, a total of 104, 205 and 83 significantly different metabolites (SDMs) were identified after being fed with FC, FA, and CF, respectively, as compared to the LA group. Furthermore, significant differences in KEGG compounds among the three comparisons exhibited similarity and were mainly associated with categories such as “Lipids”, “Hormones and transmitters”, and “Peptides”. The fatty acid content analysis indicated that the ΣMUFA was significantly higher in the LA and CF groups compared to the other two groups. In contrast, the highest level of ΣPUFA was found in the LA group. In addition, the CF group showed significantly higher expression levels of the fatty acid synthesis genes, FAS and ACC. Conversely, the expression level of the fatty acid decomposition-related gene CPT1 was the highest in the LA group. In comparison with the FA group, the expression level of FABP3 was significantly decreased in the LA and CF groups. In summary, there were significant differences observed in the metabolic profiles of crablets that metamorphosed from the megalopa under different diets. Our experimental results suggested that LA is more advantageous in the cultivation of the S. paramamosain megalopa compared to the other three diets. While it remains a diet that cannot be entirely substituted at present, LA has the potential to improve the culture performance of the S. paramamosain megalopa. The current study could provide valuable data into the development of artificial diets necessary for the future of the mud crab seedling breeding industry.

Grass carp has the highest production yield among all the farmed fish species around the world. But the molecular and genetic basis of growth traits is inadequately understood in this fish. In the present study, we apply whole-transcriptome sequencing to identify genes whose expression is different between fast and slow growing grass carp. We identified 1178 differentially expressed genes (DEGs), among which 270 were upregulated in the fast growing group and 908 upregulated in the slow growing group. The GO enrichment analysis revealed that DEGs was significantly enriched in protein synthesis and export machinery, cell division and development and metabolism, suggesting that cell division and metabolism may play key roles in development processes of fish. KEGG pathway analysis showed that MAPK signaling pathway may play a prominent role in growth difference. In addition, the majority of genes in immune responses related pathway were upregulated in the slow growing individuals. These results provide some valuable resources for understanding the molecular mechanisms of growth traits in fish.

Variability in food availability leads to condition-dependent investments in reproduction. This study is aimed at understanding the metabolic response and regulatory mechanism of female Scylla paramamosain in response to starvation in a temporal- and tissue-specific manner. The mud crabs were starved for 7 (control), 14, 28, and 40 days for histological and biochemical analysis in the hepatopancreas, ovary, and serum, as well as for RNA sequencing on the hepatopancreas and ovary. We further highlighted candidate gene modules highly linked to physiological traits. Collectively, our observations suggested that starvation triggered endogenous ovarian maturation at the expense of hepatopancreas mass, with both metabolic adjustments to optimize energy and fatty acid supply from hepatopancreas to ovary in the early phase, followed by the activation of autophagy-related pathways in both organs over prolonged starvation. These specific adaptive responses might be considered efficient strategies to stimulate ovarian maturation of Scylla paramamosain under fasting stress, which improves the nutritional value of female mud crabs and other economically important crustaceans.

The wild population resources of Coreius guichenoti have sharply declined in recent decades, and any negative factors may have a significant impact on their survival. In this study, the enzymatic stress responses of C. guichenoti to 25 and 48 μm polyethylene fragments were explored for the first time. This was achieved by evaluating the changes in physiological and biochemical indicators of the species in response to the environmental stimuli of microplastics. In this study, we observed an early stress response in the external tissues of C. guichenoti following exposure to microplastics. The TP content in skin and muscle and the MDA content in skin, gill and muscle initially showed a significant increase. The skin, gill, and muscle exhibited greater stress responses to M5 particles, whereas M3 particles caused a greater response in the intestine and especially the liver. After the removal of microplastic exposure, the stress state of the C. guichenoti would be alleviated in a short period, but it could not fully recover to the pre-exposure level. In summary, microplastics pose a significant threat to C. guichenoti. While their negative effects can be alleviated by the removal of microplastics exposure, full recovery does not occur in a short period. Continuous monitoring of microplastics in natural waters and targeted aquatic ecological restoration are essential to ensure the normal growth and reproduction of the wild population of C. guichenoti.

In this paper, a broadband absorber with a periodic composite structure based on numerical simulation of finite-difference time-domain method (FDTD) is proposed. The absorber base is titanium (Ti), on which iron tetroxide (Fe3O4) nanospheres are laid. The nanospheres are coated with molybdenum disulfide (MoS2) and lanthanum fluoride (LaF3) composites, respectively, and are periodically arranged in symmetrical rectangular arrays. The numerical analysis results show that the absorber designed in this paper had an average absorption rate of 95.00% in the light wavelength range of 200 nm to 2500 nm, with the absorption bandwidth reaching 2300 nm, which was a significant improvement compared with other absorbers, and 100.00% absorption was achieved at 300 nm and 650 nm. According to the analysis of the coupling effect of the surface plasmon resonance (SPR) and the localized surface plasmon resonance (LSPR), the ultra-broadband absorber achieved perfect absorption performance. The research results indicate that the absorber proposed in this paper is insensitive to light polarization, has a wide-angle characteristic, and is easy to realize recycling. Therefore, it has a great potential value for the application in photothermal conversion, seawater desalination, and rapid collection of sea salt.

Salinity is an ecological factor affecting the physiology, survival, and distribution of crustaceans. Additionally, salinity fluctuation detrimentally affects the composition and biological process of crustaceans. As a significant commercial aquaculture species in China, Japan, and Southeast Asian countries, the oriental river prawn, Macrobrachium nipponense, can tolerate a wide range of salinity. The transcriptome, proteome, histology, and physiology analysis were utilized to explore the physiological responses and molecular mechanisms of salinity tolerance in M. nipponense. Through the three-month culture, the statistic of growth trait illustrated the relatively excellent performance of M. nipponense in low salinity, and the higher salinity exposure significantly affected the growth of M. nipponense. In terms of the histological analysis, the gills and hepatopancreas of M. nipponense suffered varying degrees of damage. Besides, the activities of the digestive, immune-related, and metabolic enzymes were calculated. These results indicated that salinity significantly influenced trypsin and amylase in hepatopancreas, especially in 14 ppt. The immune-related enzymes were activated in high salinity. Notably, the activity of metabolic enzymes was significantly low in 7 and 14 ppt, which testified that the 7 ppt to 14 ppt were near the isotonic point of M. nipponense. In gills, hepatopancreas, and muscle, high-throughput mRNA sequencing revealed 11356, 2227, and 1819 differentially expressed genes (DEGs) by comparing the 7, 14, and 21 ppt groups with the 0ppt group, respectively. The TMT-labeling proteome identified 439 and 230 differentially expressed proteins (DEPs) in gills and hepatopancreas through the comparison of the 7, 14, and 21 ppt groups to the 0 ppt group, respectively. Additionally, through the integration of transcriptome and proteome, several pathways related to salinity adaptation were enriched, including protein export, cGMP-PKG signaling pathway, Amino sugar and nucleotide sugar metabolism, and Glycine, serine and threonine metabolism. Besides, 16 up and down-regulated proteins and related DEGs were detected through KEGG enrichment analysis, including ETHE1, BIP, chitinase (E3.2.1.14), and SARDH. Notably, no significantly regulated proteins and related DEGs were recorded by the correlation of transcriptome and proteome of 0 ppt and 7 ppt in hepatopancreas. Thus, the optimum survival salinity of M. nipponense may range from 0 ppt to 7 ppt. Overall, these results may provide valuable insights into the mechanisms underlying the culture of M. nipponense in different salinity.

Salinity is an ecological factor that affects the physiological metabolism, survival, and distribution of crustaceans. Although some crustaceans can tolerate an extensive range of salinity, drastic fluctuations can induce damage and even cause death. The oriental river prawn, Macrobrachium nipponense, is a major commercial aquaculture species in China, Japan, and Southeast Asian countries and can survive in a salinity range of 7–20. To explore the metabolic responses and molecular mechanisms of salinity tolerance in M. nipponense, a liquid chromatography–mass spectrometry-based metabolomic analysis and high-throughput RNA sequencing were combined to evaluate the metabolic effects and primary regulatory pathways in gills, hepatopancreas, and muscle of M. nipponense in response to acute high salinity stress in a time-dependent manner. Differentially expressed genes (DGEs) were identified, and total of 632, 836, and 1246 DEGs with a cutoff of significant two-fold change were differentially expressed in hepatopancreas, gills, and muscle tissues, respectively. The DEGs of hepatopancreas and gill tissues were mainly enriched in PPAR signaling pathway, longevity regulating pathway, protein digestion and absorption, and the DEGs of muscle tissue in arginine biosynthesis, adrenergic signaling in cardiomyocytes, cardiac muscle contraction, and cGMP-PKG signaling pathway. The transcriptomic response suggested that M. nipponense exposed to acute high salinity stress may regulate mechanisms related to ion exchange, metabolism, and immune responses to adapt to the environmental alteration. Through LC-MS analysis, 1432 metabolites (589 negative and 843 positive metabolites) were identified. Metabolomic analysis revealed that multiple amino acids and fatty acids were affected. Integrated transcriptome and metabolome analyses indicated that 16 pathways were identified in three tissues of M. nipponense. In addition, 24 metabolites and 34 related DEGs were recorded. Hence, salinity exposure affected metabolic processes in M. nipponense and a higher expression of aminophospholipid genes and enhanced fatty acids may be related to strengthening tolerance to acute high salinity. Overall, these results provide valuable insights into the mechanisms underlying acute high salinity stress responses and tolerance in M. nipponense.

Abstract Heavy metal Cadmium (Cd2+) pollution has become a severe environmental problem for aquatic organisms. In crustaceans, gills (Gi) and hepatopancreas (Hp) play a vital role in the toxicology. However, in Macrobrachium rosenbergill, there are few researches about gill and hepatopancreases responding to Cd2+ stress at a molecular level. In this study, transcriptomic analysis was applied to characterize gene expression profiles of gills and hepatopancreas of M. rosenbergill after Cd2+ exposure for 0 h, 3 h and 3 d. Six cDNA libraries (Gi 0 h, Gi 3 h, Gi 3 d, Hp 0 h, Hp 3 h, and Hp 3 d) were constructed and a total of 66,676 transcripts and 48,991 unigenes were annotated. Furthermore, differentially expressed genes (DEGs) were isolated by comparing the Cd2+ treated time-point libraries (3 h and 3 d group) with the control library (0 h group). The results showed that most of the DEGs were down-regulated after Cd2+ exposure and the number of DEGs among gill groups were significantly higher than those among hepatopancreas groups. GO functional and KEGG pathway analysis suggested many key DEGs in response to the Cd2+ stress, such as metallothionein and Hemocyanin. Additionally, a total of six DEGs were randomly selected to further identify their expressional profile by qPCR. The results indicated that these DEGs were involved in the response to Cd2+. This comparative transcriptome provides valuable molecular information on the mechanisms of responding to Cd2+ stress in M. rosenbergii, which lays the foundation for further understanding of heavy metal stress.

In this study, we first determined the complete mitochondrial genome of Sesarma dehaani. The mitogenome genome is a circular molecule of 15,917 bp, composed of 13 protein coding genes (PCGs), 22 tRNAs, two rRNAs, and one non-coding region. The heavy strand was predicted to have 9 PCGs, 14 tRNA genes, and a D-loop region, while the light strand was predicted to include 4 PCGs, 2 rRNA genes, 8 tRNA genes. ATG and TAA are the dominant initiation codon and stop codon, respectively. The phylogenetic analysis shows that S. dehaani and Sesarma neglectum have close relationships.

In this study, the complete mitogenome of Charybdis bimaculata was sequenced and annotated. The mitogenome is 15,441 bp in length, containing 37 classical eukaryotic mitochondrial regions (13 typical protein-coding genes (PCGs), 22 tRNA genes, two rRNA genes) and a non-coding control region. Most of the genes are initiated with ATA, ATG, and ATT, though GTG is also used as an initiation codon. Twelve PCGs stop with complete termination codon TAA and TAG, while Cob uses incomplete codon (T–). The phylogenetic relationships based on 13 PCGs show that C. bimaculata clusters closest to C. fariata and C. natator.

BACKGROUND: The oriental river prawn, Macrobrachium nipponense, is an economically and nutritionally important species of the Palaemonidae family of decapod crustaceans. To date, the sequencing of its whole genome is unavailable as a non-model organism. Transcriptomic information is also scarce for this species. In this study, we performed de novo transcriptome sequencing to produce the first comprehensive expressed sequence tag (EST) dataset for M. nipponense using high-throughput sequencing technologies. METHODOLOGY AND PRINCIPAL FINDINGS: Total RNA was isolated from eyestalk, gill, heart, ovary, testis, hepatopancreas, muscle, and embryos at the cleavage, gastrula, nauplius and zoea stages. Equal quantities of RNA from each tissue and stage were pooled to construct a cDNA library. Using 454 pyrosequencing technology, we generated a total of 984,204 high quality reads (338.59 Mb) with an average length of 344 bp. Clustering and assembly of these reads produced a non-redundant set of 81,411 unique sequences, comprising 42,551 contigs and 38,860 singletons. All of the unique sequences were involved in the molecular function (30,425), cellular component (44,112) and biological process (67,679) categories by GO analysis. Potential genes and their functions were predicted by KEGG pathway mapping and COG analysis. Based on our sequence analysis and published literature, many putative genes involved in sex determination, including DMRT1, FTZ-F1, FOXL2, FEM1 and other potentially important candidate genes, were identified for the first time in this prawn. Furthermore, 6,689 SSRs and 18,107 high-confidence SNPs were identified in this EST dataset. CONCLUSIONS: The transcriptome provides an invaluable new data for a functional genomics resource and future biological research in M. nipponense. The molecular markers identified in this study will provide a material basis for future genetic linkage and quantitative trait loci analyses, and will be essential for accelerating aquaculture breeding programs with this species.

Some patients with bipolar disorder have traumatic experience, sleep disturbance, and emotional variations, which are related to nightmare reports in clinics. We hypothesized that the nightmare experience might present some uniqueness in different types of bipolar disorder. We invited 200 healthy volunteers and 141 bipolar disorder I (BD I) and 78 bipolar disorder II (BD II) patients who had at least one nightmare lifelong to undergo tests of the Nightmare Experience Questionnaire (NEQ) and the questionnaires measuring mania, hypomania, and depression. Compared with healthy controls, both BD I and BD II patients displayed their abnormal affective states and scored significantly higher on NEQ Meaning Interpretation; BD I patients, in addition, scored higher on NEQ Horrible Stimulation. Hypomania was correlated with Horrible Simulation in BD II patients, and depression was correlated with Physical Effect and Horrible Stimulation in healthy controls. We found some NEQ scales were elevated in bipolar disorder, but these abnormalities failed to differentiate BD I from BD II. However, these results help explain the cognitive and emotional disturbances of bipolar disorder in general. [ABSTRACT FROM AUTHOR]