Advancing lung adenocarcinoma prognosis and immunotherapy prediction with a multi-omics consensus machine learning approach.

Lung adenocarcinoma (LUAD) is a tumour characterized by high tumour heterogeneity. Although there are numerous prognostic and immunotherapeutic options available for LUAD, there is a dearth of precise, individualized treatment plans. We integrated mRNA, lncRNA, microRNA, methylation and mutation data from the TCGA database for LUAD. Utilizing ten clustering algorithms, we identified stable multi-omics consensus clusters (MOCs). These data were then amalgamated with ten machine learning approaches to develop a robust model capable of reliably identifying patient prognosis and predicting immunotherapy outcomes. Through ten clustering algorithms, two prognostically relevant MOCs were identified, with MOC2 showing more favourable outcomes. We subsequently constructed a MOCs-associated machine learning model (MOCM) based on eight MOCs-specific hub genes. Patients characterized by a lower MOCM score exhibited better overall survival and responses to immunotherapy. These findings were consistent across multiple datasets, and compared to many previously published LUAD biomarkers, our MOCM score demonstrated superior predictive performance. Notably, the low MOCM group was more inclined towards 'hot' tumours, characterized by higher levels of immune cell infiltration. Intriguingly, a significant positive correlation between GJB3 and the MOCM score (R = 0.77, p < 0.01) was discovered. Further experiments confirmed that GJB3 significantly enhances LUAD proliferation, invasion and migration, indicating its potential as a key target for LUAD treatment. Our developed MOCM score accurately predicts the prognosis of LUAD patients and identifies potential beneficiaries of immunotherapy, offering broad clinical applicability.

Identification of a neuropeptide in suppressing food intake in zebrafish.

Neuropeptides play crucial roles in regulating various physiological processes in vertebrates. In this study, we identified a novel neuropeptide-encoding gene, nwk, in the genomes of some vertebrate species. The nwk cDNA was subsequently cloned from the brain of zebrafish. The Nwk precursor comprises 88 amino acids, with a putative mature peptide (Nwk-22) of 22 amino acids. Sequence analysis revealed that Nwk-22 is relatively conserved across vertebrate species. Nwk is predominantly expressed in the brain, with positive mRNA cells identified in the TPp and preoptic area. Intraperitoneal injection of Nwk-22 suppressed food intake and downregulated the mRNA expression of the orexigenic factor agouti-related peptide (agrp) in zebrafish. Additionally, a CRISPR/Cas9 approach was used to generate nwk mutant zebrafish. The nwk-/- zebrafish exhibited increased food consumption compared to wild-type controls. Furthermore, Nwk-22a injection in nwk-/- fish also suppressed agrp expression while stimulating the expression of the anorexigenic gene pomca, further supporting the anorexigenic role of Nwk. Taken together, these findings suggest that Nwk functions as an anorexigenic factor, reducing food intake by downregulating orexigenic genes like agrp and upregulating anorexigenic genes like pomc in zebrafish.

Photoluminescence Enhancement of 0D Organic-Inorganic Metal Halides via Aggregation-Induced Emission and Halide Substitution.

0D organic-inorganic metal halides (OIMHs) provide unprecedented versatility in structures and photoluminescence properties. Here, a series of bluish-white emissive 0D OIMHs, (TPE-TPP)2Sb2BrxCl8-x (x = 1.16 to 8), are prepared by assembling the 1-triphenylphosphonium-4-(1,2,2-triphenylethenyl)benzene cation (TPE-TPP)+ with antimony halides anions. Based on experimental characterizations and theoretical calculations, the emission of the 0D OIMHs are attributed to the fluorescence of the organic cations with aggregation-induced emission (AIE) properties. The 0D structure minimized the molecular motion and intermolecular interactions between (TPE-TPP)+ cations, effectively suppressing the non-radiative recombination processes. Consequently, the photoluminescence quantum efficiency (PLQE) of (TPE-TPP)2Sb2Br1.16Cl6.84 is significantly enhanced to 55.4% as compared to the organic salt (TPE-TPP)Br (20.5%). The PLQE of (TPE-TPP)2Sb2BrxCl8-x can also be readily manipulated by halide substitution, due to the competitive processes between non-radiative recombination on the inorganic moiety and the energy transfer from inorganic to organic. In addition, electrically driven light-emitting diodes (LEDs) are fabricated based on (TPE-TPP)2Sb2Br1.16Cl6.84 emitter, which exhibited bluish-white emission with a maximum external quantum efficiency (EQE) of 1.1% and luminance of 335 cd m-2. This is the first report of electrically driven LED based on 0D OIMH with bluish-white emission.

Cationic Europium-Organic Framework for Chromatographic Column Separation of Ionic Dyes and Stimuli-Responsive Chromic Properties.

A novel 3D europium-based cationic framework (Eu-CMOF) has been constructed solvothermally by employing a viologen derivative as an organic functional building unit. Notably, Eu-CMOF demonstrates its capability as a proficient aqueous-phase ion-exchange host, facilitating the remarkable rapid chromatographic column separation of new coccine and malachite green (NC3-/MG+), as well as new coccine and methylene blue (NC3-/MLB+), in mere 2 to 4 min. Adsorption thermodynamics and kinetics of anionic dyes demonstrate that Eu-CMOF exhibits a higher adsorption capacity for NC3-, as evaluated by the Langmuir model, reaching a value of 173 mg·g-1. The pseudo-second-order rate constant is determined to be 3.84 × 10-3 mg-1·g·min-1. Additionally, Eu-CMOF displays reversible photochromic and amine- and ammonia-induced vapochromic behaviors. Further mechanistic studies reveal that these chromic behaviors are primarily attributed to the generation of free viologen radical stimulated by Xe-light or electron-rich amine/ammonia. This research contributes to the development of advanced materials with applications in rapid chromatographic separation and stimuli-responsive chromic properties, showcasing the potential of Eu-CMOF as a versatile platform for practical applications.

Upregulation of HDAC9 in hippocampal neurons mediates depression-like behaviours by inhibiting ANXA2 degradation.

Major depressive disorder (MDD) is a pervasive and devastating mental disease. Broad spectrum histone deacetylase (HDAC) inhibitors are considered to have potential for the treatment of depressive phenotype in mice. However, due to its non-specific inhibition, it has extensive side effects and can not be used in clinical treatment of MDD. Therefore, finding specific HDAC subtypes that play a major role in the etiology of MDD is the key to develop corresponding specific inhibitors as antidepressants in the future. Copy number variation in HDAC9 gene is thought to be associated with the etiology of some psychiatric disorders. Herein, we found that HDAC9 was highly expressed in the hippocampus of chronic restraint stress (CRS) mouse model of depression. Upregulation of HDAC9 expression in hippocampal neurons of mice induced depression-like phenotypes, including anhedonia, helplessness, decreased dendritic spine density, and neuronal hypoexcitability. Moreover, knockdown or knockout of HDAC9 in hippocampal neurons alleviated depression-like phenotypes caused by chronic restraint stress (CRS) in WT mice. Importantly, using immunoprecipitation-mass spectrometry (IP-MS), we further found that Annexin A2 (ANXA2) was coupled to and deacetylated by HDAC9. This coupling resulted in the inhibition of ubiquitinated ANXA2 degradation and then mediates depression-like behavior. Overall, we discovered a previously unrecognized role for HDAC9 in hippocampal neurons in the pathogenesis of depression, indicating that inhibition of HDAC9 might be a promising clinical strategy for the treatment of depressive disorders.

Advancing predictive markers in lung adenocarcinoma: A machine learning-based immunotherapy prognostic prediction signature.

The prognosis of lung adenocarcinoma (LUAD) is generally poor. Immunotherapy has emerged as a promising therapeutic modality, demonstrating remarkable potential for substantially prolonging the overall survival of individuals afflicted with LUAD. However, there is currently a lack of reliable signatures for identifying patients who would benefit from immunotherapy. We conducted a comparative analysis of two immunotherapy cohorts (OAK and POPLAR) and utilized single-factor COX regression to identify genes that significantly impact the prognosis of LUAD. Based on the TCGA-LUAD dataset, we employed a combination of 101 machine learning algorithms to construct a model and selected the optimal model. The model was validated on five GEO datasets and compared with 144 previously published signatures to assess its performance. Subsequently, we explored the underlying biological mechanisms through tumor mutation burden analysis, enrichment analysis, and immune infiltration analysis. An immunotherapy prognostic prediction signature (IPPS) was constructed based on 13 genes, showing robust performance in the TCGA-LUAD dataset. IPPS exhibited consistent predictive accuracy in the validation cohorts. Compared to 144 previously published signatures, IPPS consistently ranked among the top in terms of C-index values. Further exploration revealed differences between high and low-IPPS groups in terms of tumor mutation burden, pathway enrichment, and immune infiltration. IPPS demonstrates strong predictive capabilities for the prognosis of LUAD patients, offering the potential to identify suitable candidates for immunotherapy and contribute to precision treatment strategies for LUAD.

D-Limonene Inhibits Pichia kluyveri Y-11519 in Sichuan Pickles by Disrupting Metabolism.

The Pichia kluyveri, a proliferation commonly found in Sichuan pickles (SCPs), can accelerate the growth and reproduction of spoilage bacteria, causing off-odor development and decay. Although D-limonene, a common natural preservative, effectively restricts P. kluyveri, its inhibitory mechanism remains unclear. This study aimed to elucidate this molecular mechanism by investigating the impact on basic P. kluyveri metabolism. The findings revealed that D-limonene inhibited P. kluyveri growth and disrupted the transcription of the genes responsible for encoding the enzymes involved in cell wall and membrane synthesis, oxidative phosphorylation, glycolysis, and the tricarboxylic acid (TCA) cycle pathway. The results indicated that these events disrupted crucial metabolism such as cell wall and membrane integrity, adenosine triphosphate (ATP) synthesis, and reactive oxygen species (ROS) balance. These insights provided a comprehensive understanding of the inhibitory effect of D-limonene on the growth and reproduction of P. kluyveri while highlighting its potential application in the SCP industry.

Tailoring Ionic Liquid Chemical Structure for Enhanced Interfacial Engineering in Two-Step Perovskite Photovoltaics.

Ionic liquids (ILs) have emerged as versatile tools for interfacial engineering in perovskite photovoltaics. Their multifaceted application targets defect mitigation at SnO2 -perovskite interfaces, finely tuning energy level alignment, and enhancing charge transport, meanwhile suppressing non-radiative recombination. However, the diverse chemical structures of ILs present challenges in selecting suitable candidates for effective interfacial modification. This study adopted a systematic approach, manipulating IL chemical structures. Three ILs with distinct anions are introduced to modify perovskite/SnO2 interfaces to elevate the photovoltaic capabilities of perovskite devices. Specifically, ILs with different anions exhibited varied chemical interactions, leading to notable passivation effects, as confirmed by Density Functional Theory (DFT) calculation. A detailed analysis is also conducted on the relationship between the ILs' structure and regulation of energy level arrangement, work function, perovskite crystallization, interface stress, charge transfer, and device performance. By optimizing IL chemical structures and exploiting their multifunctional interface modification properties, the champion device achieved a PCE of 24.52% with attentional long-term stability. The study establishes a holistic link between IL structures and device performance, thereby promoting wider application of ILs in perovskite-based technologies.

Mutation of spexin2 promotes feeding, somatic growth, adiposity, and insulin resistance in zebrafish.

Spexin2 (spx2) is a newly identified gene in vertebrates, but its biological functions remain unclear. In this study, we cloned the full-length cDNA of spx2 in zebrafish. The 288-bp open reading frame encodes a protein of 95 amino acids that contains a 14 amino acids mature peptide. Spx2 is highly expressed in brain and testis. Its expression was significantly downregulated in the hypothalamus after feeding treatment and 7 days of food deprivation. Using a zebrafish spx2-/- mutant line, we observed a greater amount of food intake and changes in mRNA levels of feeding factors. We found that, SPX2 acts as a satiety factor that inhibits food intake by downregulating the expression of agouti-related neuropeptide (agrp). Moreover, spx2 mutant fish exhibited a larger body size, excessive lipid accumulation, and insulin resistance. Taken together, our results revealed that SPX2 functions as a satiety factor involved in energy metabolic regulation in zebrafish.

Molecular characterization and functional study of the NLRP3 inflammasome genes in Tetraodon nigroviridis.

Nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome is an important inflammasome in mammals, which is of great significance to eliminate pathogens. However, the research of the NLRP3 inflammasome in teleost is limited. Tetraodon nigroviridis has the characteristics of small genome and easy feeding, which can be used as a model for the study of fish immune function. In present study, three NLRP3 inflammasome component genes (NLRP3, ASC and caspase-1) in T. nigroviridis has been cloned. Real-time fluorescence quantitative PCR showed that TnNLRP3 (T. nigroviridis NLRP3), TnASC (T. nigroviridis ASC) and Tncaspase-1 (T. nigroviridis caspase-1) mRNA in various tissues from health T. nigroviridis were highly expressed in immune-related tissues, such as spleen, gill, head kidney and intestine. After Vibrio parahemolyticus infection, the expression of TnNLRP3, TnASC and Tncaspase-1 mRNA in spleen, gill, head kidney reached a peak at 24 h, and the expression levels of these genes in intestine were the highest at 48 h. After the transfection of TnASC-pAcGFP-N1 monomer GFP plasmid into cos-7 cells, ASC specks, the activation marker of NLRP3 inflammasome, were observed. Bimolecular fluorescence complementarity and fluorescence colocation experiment showed that TnASC and Tncaspase-1 of TnNLRP3 inflammasome were co-located near the cell nucleus, and potentially interacted with each other. NLRP3 inflammasome inducer nigericin and agonist ATP could significantly induce the expression of TnNLRP3, TnASC and Tncaspase-1 mRNA, and activation of NLRP3 inflammasome could promote the generation of mature TnIL-1ß (T. nigroviridis IL-1ß). These results uncover that T. nigroviridis NLRP3 inflammasome could participate in the antibacterial immune response and the generation of mature TnIL-1ß after activation.

The flagellin of Vibrio parahaemolyticus induces the inflammatory response of Tetraodon nigroviridis through TLR5M.

Vibrio parahaemolyticus is an important marine pathogen that cause inflammation even death in teleost. It has brought huge economic losses to aquaculture and serious threats to the sustainable development of marine fisheries. Here, we isolated the DNA, RNA, and total flagellin from V. parahaemolyticus, and obtained the primary spleen and head kidney cells (including leukocytes) from Tetraodon nigroviridis. V. parahaemolyticus DNA, RNA, and total flagellin were used to treat the T. nigroviridis primary cells described above. The results show that the nitric oxide (NO) production and respiratory burst response were significantly induced after stimulation with V. parahaemolyticus total flagellin in T. nigroviridis head kidney and spleen cells. And total flagellin could promote the gene expression and protein production of IL-1ß in T. nigroviridis leukocytes. T. nigroviridis TLR5M (TnTLR5M) and TLR5S (TnTLR5S) ORF sequences were obtained as the main recognition receptor for flagellin. Real-time fluorescent quantitative PCR (qRT-PCR) was performed to detect the expression of pattern recognition receptor TnTLR5M and TnTLR5S, the important signal molecule of inflammatory system TnMyD88 and TnTRAF6, and inflammatory cytokines TnIL-1ß and TnIFN-γ2. The results show that there were a significant upregulation after challenge with V. parahaemolyticus total flagellin. We further demonstrated that the total flagellin of V. parahaemolyticus could activate the luciferase activity of the NF-κB reporter gene mediated by TnTLR5M. Overall, our results suggest that V. parahaemolyticus total flagellin activated the NO production, respiratory burst response, and inflammatory cytokines expressions, such as TnIL-1ß and TnIFN-γ2, through the TnTLR5M-NF-κB signaling pathway in T. nigroviridis.

Inhibition of oocyte maturation by nitric oxide synthase 1 (NOS1) in zebrafish.

It is well-documented that nitric oxide (NO) is an important regulator of oocyte maturation in mammals. Conversely, the function of NO during oocyte maturation has received little attention in nonmammalian vertebrates. NO is produced from L-arginine through the action of the enzyme NO synthase (NOS). Herein, we examined the expression, hormonal regulation, and involvement of NOS in meiotic signaling in zebrafish oocyte maturation. Three types of nos genes, nos1, nos2a, and nos2b, have been identified in zebrafish. We found that the expression of nos1 was highest in the ovary among the three nos genes, with maximal expression in full-grown (FG)-stage follicles during folliculogenesis. In addition, the concentration of NO was reduced during oocyte maturation and this corresponded with the decreased expression of nos1 in the follicular cell layers, suggesting that NOS1-derived NO may be one of the inhibitors of oocyte maturation in zebrafish. This is the first description of nos1 involvement in oocyte maturation in vertebrates. Moreover, the NO donor SNAP (S-nitroso-l-acetyl penicillamine) partially attenuates human chorionic gonadotropin (hCG)- and 17,20ß-P-induced GVBD (germinal vesicle breakdown), perhaps by increasing cGMP levels during oocyte maturation. Finally, our results showed that SNAP and the cGMP analog 8-Br-cGMP inhibited hCG-induced mitogen-activated protein kinase (MAPK) activation, further indicating that NO and cGMP block oocyte maturation in zebrafish.

Distinct Roles of Estrogen Receptors in the Regulation of Vitellogenin Expression in Orange-Spotted Grouper (Epinephelus coioides).

During their breeding season, estrogen induces vitellogenin (VTG) production in the liver of teleost fish through estrogen receptors (ERs) that support oocyte vitellogenesis. There are at least three ER subtypes in teleost fish, but their roles in mediating E2-induced VTG expression have yet to be ascertained. In this study, we investigated the expression of vtgs and ers in the liver of orange-spotted grouper (Epinephelus coioides). Their expression levels were significantly increased in the breeding season and were upregulated by an estradiol (E2) injection in female fish, except for the expression of erß1. The upregulation of vtgs, erα and erß2 by E2 was also observed in primary hepatocytes, but these stimulatory effects could be abolished by ER antagonist ICI182780 treatment. Subsequent studies showed that ERß antagonist Cyclofenil downregulated the E2-induced expression of vtg, erα, and erß2, while the ERß agonist DPN simulated their expression. Knockdown of erß2 by siRNA further confirmed that ERß2 mediated the E2-induced expression of vtgs and erα. To reveal the mechanism of ERß2 in the regulation of erα expression, the erα promoter was cloned, and its activity was examined in cells. E2 treatment simulated the activity of the erα promoter in the presence of ERß2. Deletions and site-directed mutations showed that the E2 up-regulated transcriptional activity of erα occurs through a classical half-estrogen response element- (ERE) dependent pathway. This study reveals the roles of ER subtypes in VTG expression in orange-spotted grouper and provides a possible explanation for the rapid and efficient VTG production in this species during the breeding season.

Dimethylammonium Cation-Induced 1D/3D Heterostructure for Efficient and Stable Perovskite Solar Cells.

Mixed-dimensional perovskite engineering has been demonstrated as a simple and useful approach to achieving highly efficient and more-durable perovskite solar cells (PSCs), which have attracted increasing research interests worldwide. In this work, 1D/3D mixed-dimensional perovskite has been successfully obtained by introducing DMAI via a two-step deposition method. The additive DMA+ can facilitate the crystalline growth and form 1D DMAPbI3 at grain boundaries of 3D perovskite, leading to improved morphology, longer charge carrier lifetime, and remarkably reduced bulk trap density for perovskite films. Meanwhile, the presence of low-dimension perovskite is able to prevent the intrusion of moisture, resulting in enhanced long-term stability. As a result, the PSCs incorporated with 1D DMAPbI3 exhibited a first-class power conversion efficiency (PCE) of 21.43% and maintained 85% of their initial efficiency after storage under ambient conditions with ~45% RH for 1000 h.

Development and validation of nomograms to intraoperatively predict metastatic patterns in regional lymph nodes in patients diagnosed with esophageal cancer.

BACKGROUND: An accurate intraoperative prediction of lymph node metastatic risk can help surgeons in choosing precise surgical procedures. We aimed to develop and validate nomograms to intraoperatively predict patterns of regional lymph node (LN) metastasis in patients with esophageal cancer. METHODS: The prediction model was developed in a training cohort consisting of 487 patients diagnosed with esophageal cancer who underwent esophagectomy with complete LN dissection from January 2016 to December 2016. Univariate and multivariable logistic regression were used to identify independent risk factors that were incorporated into a prediction model and used to construct a nomogram. Contrast-enhanced computed tomography reported LN status and was an important comparative factor of clinical usefulness in a validation cohort. Nomogram performance was assessed in terms of calibration, discrimination, and clinical usefulness. An independent validation cohort comprised 206 consecutive patients from January 2017 to December 2017. RESULTS: Univariate analysis and multivariable logistic regression revealed three independent predictors of metastatic regional LNs, three independent predictors of continuous regional LNs, and two independent predictors of skipping regional LNs. Independent predictors were used to build three individualized prediction nomograms. The models showed good calibration and discrimination, with area under the curve (AUC) values of 0.737, 0.738, and 0.707. Application of the nomogram in the validation cohort yielded good calibration and discrimination, with AUC values of 0.728, 0.668, and 0.657. Decision curve analysis demonstrated that the three nomograms were clinically useful in the validation cohort. CONCLUSION: This study presents three nomograms that incorporate clinicopathologic factors, which can be used to facilitate the intraoperative prediction of metastatic regional LN patterns in patients with esophageal cancer.

Recognition of DAP and activation of NF-κB by cytosolic sensor NOD1 in Oreochromis niloticus.

As a lower vertebrate, the immune defense mechanism of fish mainly depends on the innate immune system. Nucleotide-binding oligomerization domain-like receptors (NLRs) are an important class of pattern recognition receptors in the innate immune system. In this study, NOD1 gene was cloned and characterized in Nile tilapia (Oreochromis niloticus). The ORF of Nile tilapia NOD1 gene was 2826 bp long and encoded 941 amino acid residues with a structure of CARD-NACHT-LRRs that was similar to the other counterparts in mammals and fishes. Phylogenetic and synteny analysis showed that NOD1 was conserved among different fishes and existed at least in the early stage of fish evolution. Expression pattern revealed that NOD1 mRNA was constitutively expressed in the tested tissues, while had high expression level in main immune organs and mucosal immune tissues (liver, head kidney, spleen, blood, gill, and intestine). Following Streptococcus agalactiae challenge, Nile tilapia NOD1 mRNA expression levels were altered in immune organs (liver, head kidney, spleen, blood), and the expression pattern was similar in liver, spleen and blood. Furthermore, the ligand recognition and signaling pathway of Nile tilapia NOD1 were also analyzed, it showed that NOD1 could recognize Tri-DAP intracellularly and activated NF-κB signaling pathway. In summary, our results indicated that the Nile tilapia NOD1 may play an important role in innate immune system and provided a basis for the functional study of NOD1 in teleost.

Knockout of tac3 genes in zebrafish shows no impairment of reproduction.

Neurokinin B (NKB) plays a pivotal role in the regulation of reproduction in vertebrates. However, whether this neuropeptide is dispensable for reproduction in teleosts remains unknown. In order to reveal its authentic functions in fish, in this study, two tachykinin 3 (tac3) genes encoding Nkbs were functional mutated in zebrafish using the Transcription Activator-like Effector Nucleases (TALEN) technology. We established tac3a-/-, tac3b-/- and tac3a-/-;tac3b-/- mutant lines, and investigated their reproductive performance and ontogeny. According to our study, spermatogenesis and folliculogenesis were not impaired in tac3a-/-, tac3b-/- and tac3a-/-;tac3b-/- mutant lines, but changes in the expression of genes related to reproductive axis were observed after loss of Tac3, suggesting that possible compensatory response was activated to maintained the reproductive function in zebrafish. In summary, our results indicate that mutation of tac3 genes do not disrupt the reproduction in zebrafish unlike in mammals, revealing the plasticity of reproductive neuroendocrine system in the brain of zebrafish.

Single-Cell Atlas of Adult Testis in Protogynous Hermaphroditic Orange-Spotted Grouper, Epinephelus coioides.

Spermatogenesis is a process of self-renewal and differentiation in spermatogonial stem cells. During this process, germ cells and somatic cells interact intricately to ensure long-term fertility and accurate genome propagation. Spermatogenesis has been intensely investigated in mammals but remains poorly understood with regard to teleosts. Here, we performed single-cell RNA sequencing of ~9500 testicular cells from the male, orange-spotted grouper. In the adult testis, we divided the cells into nine clusters and defined ten cell types, as compared with human testis data, including cell populations with characteristics of male germ cells and somatic cells, each of which expressed specific marker genes. We also identified and profiled the expression patterns of four marker genes (calr, eef1a, s100a1, vasa) in both the ovary and adult testis. Our data provide a blueprint of male germ cells and supporting somatic cells. Moreover, the cell markers are candidates that could be used for further cell identification.

Physical interactions facilitate sex change in the protogynous orange-spotted grouper, Epinephelus coioides.

Sex change in teleost fishes is commonly regulated by social factors. In species that exhibit protogynous sex change, such as the orange-spotted grouper Epinephelus coioides, when the dominant males are removed from the social group, the most dominant female initiates sex change. The aim of this study was to determine the regulatory mechanisms of socially controlled sex change in E. coioides. We investigated the seasonal variation in social behaviours and sex change throughout the reproductive cycle of E. coioides, and defined the behaviour pattern of this fish during the establishment of a dominance hierarchy. The social behaviours and sex change in this fish were affected by season, and only occurred during the prebreeding season and breeding season. Therefore, a series of sensory isolation experiments was conducted during the breeding season to determine the role of physical, visual and olfactory cues in mediating socially controlled sex change. The results demonstrated that physical interactions between individuals in the social groups were crucial for the initiation and completion of sex change, whereas visual and olfactory cues alone were insufficient in stimulating sex change in dominant females. In addition, we propose that the steroid hormones 11-ketotestosterone and cortisol are involved in regulating the initiation of socially controlled sex change.

Transcriptome profiling of laser-captured germ cells and functional characterization of zbtb40 during 17alpha-methyltestosterone-induced spermatogenesis in orange-spotted grouper (Epinephelus coioides).

BACKGROUND: Spermatogenesis is an intricate process regulated by a finely organized network. The orange-spotted grouper (Epinephelus coioides) is a protogynous hermaphroditic fish, but the regulatory mechanism of its spermatogenesis is not well-understood. In the present study, transcriptome sequencing of the male germ cells isolated from orange-spotted grouper was performed to explore the molecular mechanism underlying spermatogenesis. RESULTS: In this study, the orange-spotted grouper was induced to change sex from female to male by 17alpha-methyltestosterone (MT) implantation. During the spermatogenesis, male germ cells (spermatogonia, spermatocytes, spermatids, and spermatozoa) were isolated by laser capture microdissection. Transcriptomic analysis for the isolated cells was performed. A total of 244,984,338 clean reads were generated from four cDNA libraries. Real-time PCR results of 13 genes related to sex differentiation and hormone metabolism indicated that transcriptome data are reliable. RNA-seq data showed that the female-related genes and genes involved in hormone metabolism were highly expressed in spermatogonia and spermatozoa, suggesting that these genes participate in the spermatogenesis. Interestingly, the expression of zbtb family genes showed significantly changes in the RNA-seq data, and their expression patterns were further examined during spermatogenesis. The analysis of cellular localization of Eczbtb40 and the co-localization of Eczbtb40 and Eccyp17a1 in different gonadal stages suggested that Eczbtb40 might interact with Eccyp17a1 during spermatogenesis. CONCLUSIONS: Our study, for the first time, investigated the transcriptome of the male germ cells from orange-spotted grouper, and identified functional genes, GO terms, and KEGG pathways involved in spermatogenesis. Furthermore, Eczbtb40 was first characterized and its role during spermatogenesis was predicted. These data will contribute to future studies on the molecular mechanism of spermatogenesis in teleosts.