New alkaloids from Stemona tuberosa and structural revision of tuberostemonols P and R.

Three Stemona alkaloids named stemotuberines A-C (1-3) with unique C17N frameworks, presumably formed by elimination of the C-11-C-15 lactone ring of the stichoneurine skeleton, were isolated from the roots of Stemona tuberosa. Their structures were elucidated by spectroscopic analysis, X-ray diffraction, and computational methods. Compounds 2 and 3 showed inhibition (IC50 values of 37.1 and 23.2 µM, respectively) against LPS-induced nitric oxide production in RAW 264.7 cells. In addition, concern was expressed about the reported plant origin (S. sessilifolia) of the recently described alkaloids tuberostemonols O-R (4-7), which should be S. tuberosa. NMR calculations indicated structural misassignment of these compounds except for 6. Isolation of tuberostemonol P (5) from our material of S. tuberosa allowed for a close examination of the spectroscopic data leading to the revised structure 5a. Tuberostemonol R (7) was found to have identical 1H and 13C NMR data to the well-known alkaloid croomine, and therefore its structure including relative stereochemistry must be revised as 7a.

Design, Synthesis, and Biological Evaluation of Novel Purine Derivatives as Herbicide Safeners.

Mesosulfuron-methyl, an inhibitor of acetolactate synthase (ALS), has been extensively used in wheats. However, it can damage wheat (Triticum aestivum) and even lead to crop death. Herbicide safeners selectively shield crops from such damage without compromising weed control. To mitigate the phytotoxicity of mesosulfuron-methyl in crops, several purine derivatives were developed based on active substructure splicing. The synthesized title compounds underwent thorough characterization using infrared spectroscopy, 1H nuclear magnetic resonance (1H NMR), 13C nuclear magnetic resonance (13C NMR), and high-resolution mass spectrometry. We evaluated chlorophyll and glutathione contents as well as various enzyme activities to evaluate the safer activity of these compounds. Compounds III-3 and III-7 exhibited superior activity compared with the safener mefenpyr-diethyl. Molecular structure analysis, along with predictions of absorption, distribution, metabolism, excretion, and toxicity, indicated that compound III-7 shared pharmacokinetic traits with the commercial safener mefenpyr-diethyl. Molecular docking simulations revealed that compound III-7 competitively bound to the ALS active site with mesosulfuron-methyl, elucidating the protective mechanism of the safeners. Overall, this study highlights purine derivatives as potential candidates for novel safener development.

Giant pulmonary artery aneurysm associated with SARS-CoV-2 infection and Actinomyces odontolyticus sepsis: A case report.

Giant septic pulmonary artery aneurysms (PAAs) are rare but important entities, with few cases having been reported worldwide. Early diagnosis and prompt treatment are crucial in the management of such cases. We report a 56-year-old female patient presenting with fatigue, nausea and vomiting who was first diagnosed with diabetic ketoacidosis (DKA) and developed life-threatening giant infectious PAA secondary to SARS-CoV-2 infection and Actinomyces odontolyticus sepsis. The patient did not develop any specific symptoms, and enhanced computed tomography (CT) revealed a massive PAA of 5.6 × 4.9 cm in size at the left pulmonary hilar with normal pulmonary artery (PA) pressures. After multidisciplinary discussion and after considering the critical condition accompanied by sepsis increased the risk of surgery, endovascular treatment was the first therapy of choice for the patient; nevertheless, the patient ultimately opted for hospice care. This case report aims to raise awareness of PAAs, which are rare but potentially fatal complications of infectious diseases such as COVID-19 pneumonia and Actinomyces odontolyticus sepsis.

A 12-Vertex Metallacarborane of Silver(I).

The discovery of ferrocene in 1951 was a significant landmark in the field of organometallic chemistry, and since then, numerous sandwich- or half-sandwich metallic complexes have been reported. However, silver stands as an intriguing exception in this regard, and knowledge of its bonding situation has remained undisclosed. Herein, unprecedented 12-vertex metallacarboranes of Ag(I) (2a and 2b) were synthesized through the reaction of sodium hexamethyldisilazide (NaHMDS) with the mixture of nido-C2B9 carborane anion-supported N-heterocyclic carbene precursors (1a and 1b) and [Ag(PPh3)Cl]4. The X-ray structural analysis of the resulting metallacarboranes revealed a unique "slipped" half-sandwich structure, which is a rarity among cyclopentadienyl analogues. DFT calculations provided insights into the asymmetric π-interactions between the pentagonal C2B3 face and the silver ion.

Deciphering the population structure and genetic basis of growth traits from whole-genome resequencing of the leopard coral grouper ( Plectropomus leopardus).

The leopard coral grouper ( Plectropomus leopardus) is a species of significant economic importance. Although artificial cultivation of P. leopardus has thrived in recent decades, the advancement of selective breeding has been hindered by the lack of comprehensive population genomic data. In this study, we identified over 8.73 million single nucleotide polymorphisms (SNPs) through whole-genome resequencing of 326 individuals spanning six distinct groups. Furthermore, we categorized 226 individuals with high-coverage sequencing depth (≥14×) into eight clusters based on their genetic profiles and phylogenetic relationships. Notably, four of these clusters exhibited pronounced genetic differentiation compared with the other populations. To identify potentially advantageous loci for P. leopardus, we examined genomic regions exhibiting selective sweeps by analyzing the nucleotide diversity ( θπ) and fixation index ( F ST) in these four clusters. Using these high-coverage resequencing data, we successfully constructed the first haplotype reference panel specific to P. leopardus. This achievement holds promise for enabling high-quality, cost-effective imputation methods. Additionally, we combined low-coverage sequencing data with imputation techniques for a genome-wide association study, aiming to identify candidate SNP loci and genes associated with growth traits. A significant concentration of these genes was observed on chromosome 17, which is primarily involved in skeletal muscle and embryonic development and cell proliferation. Notably, our detailed investigation of growth-related SNPs across the eight clusters revealed that cluster 5 harbored the most promising candidate SNPs, showing potential for genetic selective breeding efforts. These findings provide a robust toolkit and valuable insights into the management of germplasm resources and genome-driven breeding initiatives targeting P. leopardus.

Effects of ulinastatin combined with dexmedetomidine on cognitive dysfunction and emergence agitation in elderly patients who underwent total hip arthroplasty.

BACKGROUND: With the continuous growth of the modern elderly population, the risk of fracture increases. Hip fracture is a common type of fracture in older people. Total hip arthroplasty (THA) has significant advantages in relieving chronic pain and promoting the recovery of hip joint function. AIM: To investigate the effect of ulinastatin combined with dexmedetomidine (Dex) on the incidences of postoperative cognitive dysfunction (POCD) and emergence agitation in elderly patients who underwent THA. METHODS: A total of 397 patients who underwent THA from February 2019 to August 2022. We conducted a three-year retrospective cohort study in Shaanxi Provincial People's Hospital. Comprehensive demographic data were obtained from the electronic medical record system. We collected preoperative, intraoperative, and postoperative data. One hundred twenty-nine patients who were administered Dex during the operation were included in the Dex group. One hundred fifty patients who were intravenously injected with ulinastatin 15 min before anesthesia induction were included in the ulinastatin group. One hundred eighteen patients who were administered ulinastatin combined with Dex during the operation were included in the Dex + ulinastatin group. The patients' perioperative conditions, hemodynamic indexes, postoperative Mini-Mental State Examination (MMSE) scores, Ramsay score, incidence of POCD, and serum inflammatory cytokines were evaluated. RESULTS: There was a significant difference in the 24 h visual analogue scale score among the three groups, and the score in the Dex + ulinastatin group was the lowest (P < 0.05). Compared with the Dex and ulinastatin group, the MMSE scores of the Dex + ulinastatin group were significantly increased at 1 and 7 d after the operation (all P < 0.05). Compared with those in the Dex and ulinastatin groups, incidence of POCD, levels of serum inflammatory cytokines in the Dex + ulinastatin group were significantly decreased at 1 and 7 d after the operation (all P < 0.05). The observer's assessment of the alertness/sedation score and Ramsay score of the Dex + ulinastatin group were significantly different from those of the Dex and ulinastatin groups on the first day after the operation (all P < 0.05). CONCLUSION: Ulinastatin combined with Dex can prevent the occurrence of POCD and emergence agitation in elderly patients undergoing THA.

DGK5ß-derived phosphatidic acid regulates ROS production in plant immunity by stabilizing NADPH oxidase.

In plant immunity, phosphatidic acid (PA) regulates reactive oxygen species (ROS) by binding to respiratory burst oxidase homolog D (RBOHD), an NADPH oxidase responsible for ROS production. Here, we analyze the influence of PA binding on RBOHD activity and the mechanism of RBOHD-bound PA generation. PA binding enhances RBOHD protein stability by inhibiting vacuolar degradation, thereby increasing chitin-induced ROS production. Mutations in diacylglycerol kinase 5 (DGK5), which phosphorylates diacylglycerol to produce PA, impair chitin-induced PA and ROS production. The DGK5 transcript DGK5ß (but not DGK5α) complements reduced PA and ROS production in dgk5-1 mutants, as well as resistance to Botrytis cinerea. Phosphorylation of S506 residue in the C-terminal calmodulin-binding domain of DGK5ß contributes to the activation of DGK5ß to produce PA. These findings suggest that DGK5ß-derived PA regulates ROS production by inhibiting RBOHD protein degradation, elucidating the role of PA-ROS interplay in immune response regulation.

Integrated Virtual Screening and Validation toward Potential HPPD Inhibition Herbicide.

4-Hydroxyphenylpyruvate dioxygenase (EC 1.13.11.27, HPPD) is one of the most widely studied herbicide targets and has gained significant attention. To identify potential effective HPPD inhibitors, a rational multistep virtual screening workflow was built, which included CBP models (based on the receptor-ligand interactions in the crystal complex), Hypogen models with activity prediction ability (according to the derivation of structure-activity relationships from a set of molecules with reported activity values), and a consensus docking procedure (consisting of LibDock, Glide, and CDOCKER). About 1 million molecules containing diketone or ß-keto-enol substructures were filtered by Lipinski's rules, CBP model, and Hypogen model. A total of 12 compounds with similar docking postures were generated by consensus docking. Eventually, four molecules were screened based on the specific binding pattern and affinity of the HPPD inhibitor. The biological evaluation in vivo displayed that compounds III-1 and III-2 exhibited comparable herbicidal activity to isoxaflutole and possessed superior safety on various crops (wheat, rice, sorghum, and maize). The ADMET prediction (absorption, distribution, metabolism, excretion, and toxicity) showed that compound III possessed relatively good toxicological results. This work provides a theoretical basis and valuable reference for the virtual screening and molecular design of novel HPPD inhibition herbicides.

Efficacy and Safety of Repetitive Transcranial Magnetic Stimulation in Cerebellar Ataxia: a Systematic Review and Meta-analysis.

Cerebellar ataxia(CA) is defined as a degenerative disease of the nervous system. Repetitive transcranial magnetic stimulation (rTMS) has been a promising treatment for neurological and psychiatric diseases. Hence, to find out whether cerebellar rTMS impacts CA as a potential therapy, we performed a systematic review and meta-analysis. Qualified studies through a systematic search were retrieved for randomized controlled trials (RCTs) using acknowledged databases. Review Manager 5.4 software was employed to synthesize the data. A total of seven studies were identified as eligible and included in the quantitative review. Comparing real and sham-rTMS interventions, the utilization of rTMS on cerebellum improved the scale for the assessment and rating of ataxia (SARA) (SMD - 0.87, 95% CI - 1.41 to - 0.34; P = 0.001; I2 = 62%), the International Cooperative Ataxia Rating Scale (ICARS) (SMD - 1.06, 95% CI - 1.47 to - 0.64; P < 0.00001; I2 = 0%) and Berg balance Scale (BBS) (SMD 0.76, 95% CI 0.33 to 1.19; P = 0.0005; I2 = 39%). The subgroup analysis demonstrated high-frequency of rTMS had a positive effect (SMD - 1.28, 95% CI - 1.82 to - 0.74; P < 0.00001; I2 = 0%). For the safety, the incidence of adverse events between the two groups was not significantly different (OR 1.73, 95% CI 0.55 to 5.46; P = 0.35; I2 = 0%). In conclusion, this meta-analysis provided limited evidence, suggesting a possible strategy that rTMS over the cerebellum could be a viable therapy for symptoms associated with CA. Besides, rTMS intervention was well-attended and did not result in unanticipated negative effects.

miR-460b-5p promotes proliferation and differentiation of chicken myoblasts and targets RBM19 gene.

The meat production of broilers is crucial to economic benefits of broiler industries, while the slaughter performance of broilers is directly determined by skeletal muscle development. Hence, the broiler breeding for growth traits shows a great importance. As a kind of small noncoding RNA, microRNA (miRNA) can regulate the expression of multiple genes and perform a wide range of regulation in organisms. Currently, more and more studies have confirmed that miRNAs are closely associated with skeletal muscle development of chickens. Based on our previous miR-seq analysis (accession number: PRJNA668199), miR-460b-5p was screened as one of the key miRNAs probably involved in the growth regulation of chickens. However, the regulatory effect of miR-460b-5p on the development of chicken skeletal muscles is still unclear. Therefore, miR-460b-5p was further used for functional validation at the cellular level in this study. The expression pattern of miR-460b-5p was investigated in proliferation and differentiation stages of chicken primary myoblasts. It was showed that the expression level of miR-460b-5p gradually decreased from the proliferation stage (GM 50%) to the lowest at 24 h of differentiation. As differentiation proceeded, miR-460b-5p expression increased significantly, reaching the highest and stabilizing at 72 h and 96 h of differentiation. Through mRNA quantitative analysis of proliferation marker genes, CCK-8 and Edu assays, miR-460b-5p was found to significantly facilitate the transition of myoblasts from G1 to S phase and promote chicken myoblast proliferation. mRNA and protein quantitative analysis of differentiation marker genes, as well as the indirect immunofluorescence results of myotubes, revealed that miR-460b-5p significantly stimulated myotube development and promote chicken myoblast differentiation. In addition, the target relationship was validated for miR-460b-5p according to the dual-luciferase reporter assay and mRNA quantitative analysis, which indicates that miR-460b-5p was able to regulate RBM19 expression by specifically binding to the 3' UTR of RBM19. In summary, miR-460b-5p has positive regulatory effects on the proliferation and differentiation of chicken myoblasts, and RBM19 is a target gene of miR-460b-5p.

Genome-Wide Analysis of Flax (Linum usitatissimum L.) Growth-Regulating Factor (GRF) Transcription Factors.

Flax is an important cash crop globally with a variety of commercial uses. It has been widely used for fiber, oil, nutrition, feed and in composite materials. Growth regulatory factor (GRF) is a transcription factor family unique to plants, and is involved in regulating many processes of growth and development. Bioinformatics analysis of the GRF family in flax predicted 17 LuGRF genes, which all contained the characteristic QLQ and WRC domains. Equally, 15 of 17 LuGRFs (88%) are predicted to be regulated by lus-miR396 miRNA. Phylogenetic analysis of GRFs from flax and several other well-characterized species defined five clades; LuGRF genes were found in four clades. Most LuGRF gene promoters contained cis-regulatory elements known to be responsive to hormones and stress. The chromosomal locations and collinearity of LuGRF genes were also analyzed. The three-dimensional structure of LuGRF proteins was predicted using homology modeling. The transcript expression data indicated that most LuGRF family members were highly expressed in flax fruit and embryos, whereas LuGRF3, LuGRF12 and LuGRF16 were enriched in response to salt stress. Real-time quantitative fluorescent PCR (qRT-PCR) showed that both LuGRF1 and LuGRF11 were up-regulated under ABA and MeJA stimuli, indicating that these genes were involved in defense. LuGRF1 was demonstrated to be localized to the nucleus as expected for a transcription factor. These results provide a basis for further exploration of the molecular mechanism of LuGRF gene function and obtaining improved flax breeding lines.

A Comparative Analysis of Major Cell Wall Components and Associated Gene Expression in Autotetraploid and Its Donor Diploid Rice (Oryza sativa L.) under Blast and Salt Stress Conditions.

Whole-genome duplication is a significant evolutionary mechanism in plants, with polyploid plants often displaying larger organs and enhanced adaptability to unfavorable conditions compared to their diploid counterparts. The cell wall acts as a primary defense for plant cells against external stresses, playing an essential role in the plant's resistance to various stressors. In this study, we utilized both autotetraploid and its donor diploid rice (Oryza sativa L.) to analyze their phenotypic differences comparatively, the composition of key cell wall components, and the expression of related genes under normal conditions, as well as under stress from Magnaporthe oryzae (M. oryzae) and salt. Our findings indicated that autotetraploid rice exhibits significantly larger phenotypic characteristics under normal conditions than diploid rice. At the seedling stage, the lignin, cellulose, hemicellulose, and pectin levels in autotetraploid rice were markedly lower than in diploid rice. Additionally, 24 genes associated with major cell wall components showed differential expression between diploid and tetraploid rice. At the filling stage, the lignin and pectin content in autotetraploid rice were significantly higher than in diploid rice, while the levels of cellulose and hemicellulose were notably lower. Under M. oryzae stress or salt stress, autotetraploid rice showed smaller lesion areas and less wilting than diploid rice. The increased lignin content in autotetraploid rice under M. oryzae stress suggested a stronger adaptive capacity to adverse conditions. Compared to salt stress, M. oryzae stress induced more differential expression of genes related to major cell wall components. In this study, we explored the differences in the major cell wall components of diploid and homologous tetraploid rice under various treatment conditions. This study provides valuable insights into understanding the cell wall's adaptive mechanisms in autotetraploid rice when facing blast disease and salt stress, and it reveals the differential gene expression linked to these adaptive capabilities.

Association between the sarcopenia index and abnormal liver function in the adult population in the United States: a cross-sectional study.

Background: The objective of this study was to explore the association between the sarcopenia index and abnormal liver function in adult individuals in the United States. Methodology: This study employed a rigorous cross-sectional analysis of data derived from the National Health and Nutrition Examination Survey (NHANES) conducted between 2017 and 2018. The primary objective was to investigate the correlation between the sarcopenia index and abnormal liver function. To achieve this, an advanced multivariate regression model was utilized, allowing for comprehensive analysis and meticulous adjustment of relevant variables. To ensure the robustness of the findings, a visually appealing smooth curve was constructed, and a two-stage regression model was applied for validation. Additionally, a detailed gender-stratified analysis was conducted to further explore the association between the sarcopenia index and abnormal liver function within distinct subgroups. Results: Through our rigorous participant selection process, a total of 1756 individuals were included in the study. The meticulously adjusted multivariate regression model revealed a significant negative association between the sarcopenia index and abnormal liver function, with an adjusted odds ratio (OR) of 0.73 and a 95% confidence interval (CI) ranging from 0.63 to 0.86. The robustness of this association was further supported by the visually appealing smooth curve plot. Moreover, in the gender-stratified subgroup analysis, after meticulous adjustment for confounding factors, notable differences in this association emerged (males: OR = 0.8, 95% CI: 0.66-0.98; females: OR = 0.61, 95% CI: 0.47-0.79). Conclusion: This cross-sectional study yields robust evidence indicating a negative correlation between the sarcopenia index and abnormal liver function, predominantly observed among females.

Predictive value of frailty assessment tools in patients undergoing surgery for gastrointestinal cancer: An observational cohort study.

BACKGROUND: Few studies have simultaneously compared the predictive value of various frailty assessment tools for outcome measures in patients undergoing gastrointestinal cancer surgery. Therefore, it is difficult to determine which assessment tool is most relevant to the prognosis of this population. AIM: To investigate the predictive value of three frailty assessment tools for patient prognosis in patients undergoing gastrointestinal cancer surgery. METHODS: This single-centre, observational, prospective cohort study was conducted at the Affiliated Lianyungang Hospital of Xuzhou Medical University from August 2021 to July 2022. A total of 229 patients aged ≥ 18 years who underwent surgery for gastrointestinal cancer were included in this study. We collected baseline data on the participants and administered three scales to assess frailty: The comprehensive geriatric assessment (CGA), Fried phenotype and FRAIL scale. The outcome measures were the postoperative severe complications and increased hospital costs. RESULTS: The prevalence of frailty when assessed with the CGA was 65.9%, 47.6% when assessed with the Fried phenotype, and 34.9% when assessed with the FRAIL scale. Using the CGA as a reference, kappa coefficients were 0.398 for the Fried phenotype and 0.291 for the FRAIL scale (both P < 0.001). Postoperative severe complications and increased hospital costs were observed in 29 (12.7%) and 57 (24.9%) patients, respectively. Multivariate logistic analysis confirmed that the CGA was independently associated with increased hospital costs (odds ratio = 2.298, 95% confidence interval: 1.044-5.057; P = 0.039). None of the frailty assessment tools were associated with postoperative severe complications. CONCLUSION: The CGA was an independent predictor of increased hospital costs in patients undergoing surgery for gastrointestinal cancer.

Transcriptome-Wide Analysis of Core Transcription Factors Associated with Defense Responses in Autotetraploid versus Diploid Rice under Saline Stress and Recovery.

Saline stress is a major abiotic stress that inhibits plant growth and yields worldwide. The plant transcription factor (TF) family plays an important role in converting abiotic stress signals into gene expression changes. In this study, a transcriptome-based comparative analysis was performed to investigate the global gene expression of all the TFs in diploid and autotetraploid rice during the early stage of NaCl stress and recovery period. The phenotypic data indicated that the tetraploid rice exhibited a superior salt-tolerant ability compared to the diploid rice. A total of 55 TF families were co-expressed in the tetraploid and diploid rice, and the cumulative number of TF-expressed genes was relatively higher in the diploid rice than in the tetraploid rice at all time points. Unlike the diploid rice, the overall gene expression levels of the tetraploid rice were comparable to the control during recovery. The number of differentially expressed TFs (DE-TFs) in the tetraploid rice decreased after recovery, whereas it increased to a large extent in the diploid rice. GO and KEGG pathway enrichment analysis of the DE-TFs discovered the early switching of the ABA-activated signaling pathway and specific circadian rhythm in the tetraploid rice. Combining the PPI network and heatmap analysis, some core DE-TFs were found that may have potential roles to play in tetraploid salt tolerance. This study will pave the way for elucidating the complex network regulatory mechanisms of salt tolerance in tetraploid rice.

Testicular mixed germ cell tumor: A case report.

BACKGROUND: Testicular mixed germ cell tumors (TMGCTs) are rare malignant tumors that are more common in men aged 20-40 years. TMGCTs comprise two or more types of germ cell tumors that primarily affect the testis. Their onset is undetectable; thus, early diagnosis is challenging. However, early recognition and diagnosis substantially improve patient prognosis. CASE SUMMARY: We evaluated a rare case of TMGCT in a male patient presenting with recurrent fever and left supraclavicular lymphadenectasis instead of testicular enlargement and pain, which may easily lead to misdiagnosis. We report the clinical signs and symptoms, histopathological characteristics, and immunohistochemical results of this case of malignant TMGCT. CONCLUSION: Our case, which was typical with multiple components, along with a literature review, may serve as a basis for early diagnosis.

Gene Expression Analysis of Different Organs and Identification of AP2 Transcription Factors in Flax (Linum usitatissimum L.).

Flax (Linum usitatissimum L.) is an important oilseed crop widely cultivated for its oil and fiber. This study conducted transcriptome analysis to analyze the gene expression profiles of roots, leaves, stamens, pistils, and fruits in the flax cultivar Longya10. A total of 43,471 genes were detected in the RNA-seq data, with 34,497 genes showing differential expression levels between different organs. Gene expression patterns varied across different organs, with differences observed in expression-regulating genes within specific organs. However, 23,448 genes were found to be commonly expressed across all organs. Further analysis revealed organ-specific gene expressions, with 236, 690, 544, 909, and 1212 genes identified in pistils, fruits, leaves, roots, and stamens, respectively. Gene Ontology (GO) enrichment analysis was performed on these organ-specific genes, and significant enrichment was observed in various biological processes, cellular components, and molecular functions, providing new insights for the specific growth patterns of flax organs. Furthermore, we investigated the expression differences of AP2 transcription factors in various tissues and organs of Longya10. We identified 96 AP2 genes that were differentially expressed in different organs and annotated them into various biological pathways. Our results suggest that AP2 transcription factors may play important roles in regulating the growth and development of flax organs including stress response. In summary, our study provides a comprehensive analysis of gene expression patterns in different organs and tissues of flax plant and identifies potential critical regulators of flax organ growth and development. These findings contribute to a better understanding of the molecular mechanisms underlying flax organ development and may have important implications for the genetic improvement of flax crops.

The clock gene Cryptochrome 1 is involved in the photoresponse of embryonic hatching behavior in Bombyx mori.

The hatching of insect eggs is a classic circadian behavior rhythm controlled by the biological clock. Its function is considered to impose a daily rhythm on the embryo, allowing it to hatch within a permissible time window. However, the molecular pathways through which the clock affects embryonic hatching behavior remain unclear. Here, we utilized a clock gene Cryptochrome1 (Cry1) knockout mutant to dissect the pathways by which the circadian clock affects embryonic hatching rhythm in the silkworm. In the Cry1 mutant, the embryo hatching rhythm was disrupted. Under the constant light or constant dark incubation conditions, mutant embryos lost their hatching rhythm, while wild-type embryos hatch exhibiting free-running rhythm. In the light-dark cycle (LD), the hatching rhythm of CRY1-deficient silkworms could not be entrained by the LD photoperiod during the incubation period. The messenger RNA levels and enzymatic activities of Cht and Hel in the mutant embryos were significantly reduced at circadian time 24 (CT24). Transcriptome analysis revealed significant differences in gene expression at CT24 between the Cry1 knockout mutant and the wild-type, with 2616 differentially expressed genes identified. The enriched Gene Ontology pathway includes enzyme activity, energy availability, and protein translation. Short neuropeptide F signaling was reduced in the CT24 embryonic brain of the mutant, the expression of the neuropeptide PTTH was also reduced and the rhythm was lost, which further affects ecdysteroid signaling. Our results suggested that the silkworm circadian clock affects neuropeptide-hormone signaling as well as physiological functions related to hatching, which may regulate the hatching rhythm.

Symbiotic hemolymph bacteria reduce hexavalent chromium to protect the host from chromium toxicity in Procambarus clarkii.

Hexavalent chromium (Cr(VI)) is a cytotoxic heavy metal pollutant that adversely affects all life forms. Interestingly, the crustacean Procambarus clarkii exhibits a relatively high tolerance to heavy metals. The underlying mechanisms remain unclear. In this study, we investigated the role of symbiotic bacteria in P. clarkii in alleviating Cr(VI)-induced damage and explored their potential mechanisms of action. Through transcriptomic analysis, we observed that Cr(VI) activated P. clarkii's antimicrobial immune responses and altered the bacterial composition in the hemolymph. After antibiotic treatment to reduce bacterial populations, Cr(VI)-induced intestinal and liver damage worsened, and crayfish exhibited lower levels of GSH/CAT/SOD activity. The Exiguobacterium, the symbiotic bacteria in the hemolymph of P. clarkii, were proved to be primary contributor to Cr(VI) tolerance. Further investigation suggested that it resists Cr(VI) through the activation of the ABC transporter system and the reduction of Cr(VI) via the reductase gene nfsA. To validate the role of Exiguobacterium in Cr(VI) tolerance, crayfish treated with antibiotics then supplemented with Exiguobacterium H6 and recombinant E. coli (with the nfsA gene), reduced Cr(VI)-induced ovarian damage. Overall, this study revealed that the symbiotic bacteria Exiguobacterium can absorb and reduce hexavalent chromium, mitigating Cr(VI)-induced damage in P. clarkii. These findings provide new insights into hexavalent chromium tolerance mechanisms in crustaceans.