Overcoming bubble formation in polydimethylsiloxane-made PCR chips: mechanism and elimination with a high-pressure liquid seal.

The thermal expansion of gas and the air permeability of polydimethylsiloxane (PDMS) were previously thought to be the main causes of bubbles and water loss during polymerase chain reaction (PCR), resulting in a very complex chip design and operation. Here, by calculating and characterizing bubble formation, we discovered that water vapor is the main cause of bubbling. During PCR, heat increases the volume of the bubble by a factor of only ~0.2 in the absence of water vapor but by a factor of ~6.4 in the presence of water vapor. In addition, the phenomenon of "respiration" due to the repeated evaporation and condensation of water vapor accelerates the expansion of bubbles and the loss of water. A water seal above 109 kPa can effectively prevent bubbles in a bare PDMS chip with a simple structure, which is significant for the wide application of PDMS chips.

Negative Conductivity Induced Reconfigurable Gain Metasurfaces and Their Nonlinearity.

The past decades have witnessed the rapid development of metamaterials and metasurfaces. However, loss is still a challenging problem limiting numerous practical applications, including long-range wireless communications, superscattering, and non-Hermitian physics. Recently, great effort has been made to minimize the loss, however, they are too complicated for practical implementation and still restricted by the theoretical limit. Here, we propose and experimentally realize a tunable gain metasurface induced by negative conductivity, with deep theoretical analysis from scattering theory and equivalent circuits. In the experiment, we create metasurface samples embedded with tunable negative (or positive) conductivity to achieve adjustable gain (or loss). By varying the control bias voltages, the metasurfaces can reflect incident waves with additional controllable gain. Interestingly, we find the gain metasurfaces inherently pose nonlinearities, which are beneficial for nonlinear optics and microwave applications, particularly for the nonlinear activation of wave-based neural networks.

Abscisic acid regulates Cl- efflux via the ABI5-ZAT10-SLAH3 module in chloride-stressed Malus hupehensis.

The overload of Cl- typically causes cell damage and death in plants, especially in Cl--sensitive crops. Abscisic acid (ABA) is a stress-induced phytohormone that can alleviate chloride stress by reducing Cl- accumulation; however, the mechanism is not clear. Here, we found that the application of ABA elevated Cl- efflux from roots and reduced membrane damage and cell death in chloride-stressed Malus hupehensis. MhSLAH3, a homolog of the slow anion channel from M. hupehensis, encoded a channel controlling Cl- efflux and was induced by both chloride and ABA. MhSLAH3 overexpression accelerated Cl- efflux, which enhanced the tolerance of M. hupehensis to chloride stress, and retarded chloride-induced cell death. However, the suppression of MhSLAH3 partially offset the acceleration effect of ABA on Cl- efflux. MhZAT10L was then identified as a C2H2-type transcription factor upstream of MhSLAH3, repressing MhSLAH3 transcription under chloride stress. The suppression of MhZAT10L accelerated Cl- efflux by releasing suppressed MhSLAH3, but MhZAT10L overexpression counteracted the effects of ABA on Cl- efflux. MhABI5 promoted Cl- efflux mediated by MhSLAH3 due to induction by ABA and transcriptional repression of MhZAT10L, but this function of MhABI5 was reversed by MhZAT10L overexpression. The suppression of MhABI5 diminished the positive effects of ABA on Cl- efflux and retarding cell death. Thus, ABA repressed MhZAT10L transcription by activating MhABI5, further releasing MhSLAH3 to accelerate Cl- efflux. These findings provide a new evidence of ABA regulation of Cl- efflux.

The poetry of nitrogen and carbon metabolic shifts: The role of C/N in pitaya phase change.

Pitaya, a desert plant, has an underexplored flowering mechanism due to a lack of functional validation assays. This study reveals that the transition from vegetative to generative growth in pitaya is regulated by significant metabolic shift, underscoring the importance of understanding and address the challenging issue pitaya's phase change. Lateral buds from 6-years-old 'Guanhuahong' pitaya (Hylocereus monacanthus) plants were collected on April 8th, 18th, and 28th 2023, representing early, middle, and late stages of phase transition, respectively. Results showed diminished nitrogen levels concurrent with increased carbon levels and carbon-to-nitrogen (C/N) ratios during pitaya phase transition. Transcriptomic analysis identified batches of differentially expressed genes (DEGs) involved in downregulating nitrogen metabolism and upregulating carbon metabolism. These batches of genes play a central role in the metabolic shifts that predominantly regulate the transition to the generative phase in pitaya. This study unveils the intricate regulatory network involving 6 sugar synthesis and transport, 11 photoperiod (e.g., PHY, CRY, PIF) and 6 vernalization (e.g., VIN3) pathways, alongside 11 structural flowering genes (FCA, FLK, LFY, AGL) out of a vast array of potential candidates in pitaya phase change. These findings provide insights into the metabolic pathways involved in pitaya's phase transition, offering a theoretical framework for managing flowering, guiding breeding strategies to optimize flowering timing and improve crop yields under varied nitrogen conditions.

Systemic Analyses of Anti-Cell-Senescence Active Compounds in Camellia Sect. Chrysantha Chang and Their Mechanisms.

Aging is an irreversible pathophysiological process for all organisms. The accumulation of senescent cells in pathological sites or tissues is recognized as the major cause of diseases and disorders during the aging process. Small molecules that reduce senescent cell burdens have gained increasing attention as promising intervention therapeutics against aging, but effective anti-senescence agents remain rare. Camellia Sect. Chrysantha Chang is documented as a traditional Chinese herbal medicine used by ethnic groups for many medical and health benefits, but its effect on aging is unclear. Here, we investigated the anti-senescence potential of eight C. Sect. Chrysantha Chang species. The results show that ethyl acetate fractions from these C. Sect. Chrysantha Chang species were able to delay the senescence of H9c2 cardiomyocytes except for C. pingguoensis (CPg). N-butanol fractions of C. multipetala (CM), C. petelotii var. grandiflora (CPt), and C. longzhouensis (CL) showed a senescent cell clearance effect by altering the expression levels of senescent-associated marker genes in the DNA-damage response (DDR) pathway and the senescent cell anti-apoptotic pathway (SCAPs). By using UPLC-QTOF-MS-based non-targeted metabolomics analyses, 27 metabolites from Sect. Chrysantha species were putatively identified. Among them, high levels of sanchakasaponin C and D in CM, CPt, and CL were recognized as the key bioactive compounds responsible for senescent cell clearance. This study is the first to disclose and compare the anti-cell-senescence effect of a group of C. Sect. Chrysantha Chang, including some rare species. The combination of senescent markers and metabolomics analyses helped us to reveal the differences in chemical constituents that target senescent cells. Significantly, contrary to the C. chrysantha var. longistyla (CCL), which is widely cultivated and commercialized for tea drinks, CM, CPt, and CL contain unique chemicals for managing aging and aging-related diseases. The results from this study provide a foundation for species selection in developing small-molecule-based drugs to alleviate diseases and age-related dysfunctions and may potentially be useful for advancing geroscience research.

Comparative Chloroplast Genomes Analysis Provided Adaptive Evolution Insights in Medicago ruthenica.

A perennial leguminous forage, Medicago ruthenica has outstanding tolerance to abiotic stresses. The genome of Medicago ruthenica is large and has a complex genetic background, making it challenging to accurately determine genetic information. However, the chloroplast genome is widely used for researching issues related to evolution, genetic diversity, and other studies. To better understand its chloroplast characteristics and adaptive evolution, chloroplast genomes of 61 Medicago ruthenica were assembled (including 16 cultivated Medicago ruthenica germplasm and 45 wild Medicago ruthenica germplasm). These were used to construct the pan-chloroplast genome of Medicago ruthenica, and the chloroplast genomes of cultivated and wild Medicago ruthenica were compared and analyzed. Phylogenetic and haplotype analyses revealed two main clades of 61 Medicago ruthenica germplasm chloroplast genomes, distributed in eastern and western regions. Meanwhile, based on chloroplast variation information, 61 Medicago ruthenica germplasm can be divided into three genetic groups. Unlike the phylogenetic tree constructed from the chloroplast genome, a new intermediate group has been identified, mainly consisting of samples from the eastern region of Inner Mongolia, Shanxi Province, and Hebei Province. Transcriptomic analysis showed that 29 genes were upregulated and three genes were downregulated. The analysis of these genes mainly focuses on enhancing plant resilience and adapting adversity by stabilizing the photosystem structure and promoting protein synthesis. Additionally, in the analysis of adaptive evolution, the accD, clpP and ycf1 genes showed higher average Ka/Ks ratios and exhibited significant nucleotide diversity, indicating that these genes are strongly positively selected. The editing efficiency of the ycf1 and clpP genes significantly increases under abiotic stress, which may positively contribute to plant adaptation to the environment. In conclusion, the construction and comparative analysis of the complete chloroplast genomes of 61 Medicago ruthenica germplasm from different regions not only revealed new insights into the genetic variation and phylogenetic relationships of Medicago ruthenica germplasm, but also highlighted the importance of chloroplast transcriptome analysis in elucidating the model of chloroplast responses to abiotic stress. These provide valuable information for further research on the adaptive evolution of Medicago ruthenica.

Coumestrol facilitates apoptosis in colorectal cancer cells by interacting with ZIP8 protein via the ferroptosis pathway.

Objective: So far, there have been no reports of coumestrol inhibiting colorectal cancer (CRC) through the ferroptosis pathway. This study is to investigate the mechanism of the traditional Chinese medicine monomer coumestrol in the treatment of CRC. Methods: Data on CRC transcriptome sequencing was obtained from the GEO database and TCGA database. Bioinformatics analyses were conducted to screen for CRC prognostic-related key genes and their potential binding monomers in traditional Chinese medicine. The inhibitory effect of coumestrol on CRC cell lines (COLO 205 & HCT 116) was determined using the CCK-8 assay, and cell apoptosis was assessed by flow cytometry. The content of ferrous ions was measured using the Ferrous Ion Content Assay Kit. The expression of ferroptosis pathway-related genes SLC39A8, NCOA4, VDAC2, and NOX2 before and after small interference RNA (siRNA) was examined through real-time PCR and Western blotting. Results: SLC39A8 was found to be associated with CRC clinical progression staging, and its encoded protein ZIP8 may bind to coumestrol. KEGG enrichment analysis suggested that ZIP8 plays a role in iron transmembrane transport and may affect the expression of ferroptosis pathway-related genes NCOA4, VDAC2, and NOX2. Coumestrol was found to induce apoptosis in CRC cell lines by upregulating the expression of ferroptosis pathway-related genes SLC39A8, NCOA4, VDAC2, and NOX2. However, coumestrol was unable to upregulate the expression of ferroptosis pathway-related genes in CRC cell lines after SLC39A8 interference. Conclusion: Coumestrol facilitates apoptosis in CRC cells by interacting with ZIP8 protein via the ferroptosis pathway.

Genetic variations of low-density lipoprotein cholesterol on metabolic disorders in obstructive sleep apnea.

BACKGROUND: The study aimed to explore the relationship between low-density lipoprotein cholesterol (LDL-C) genetic variants and obstructive sleep apnea (OSA) and its complications, including cardiovascular diseases (CVD), insulin resistance (IR), and metabolic syndrome (MS). METHOD: 4329 individuals with suspected OSA who underwent a comprehensive assessment of anthropometric, biochemical, and polysomnography (PSG) data, along with 30 LDL-C single nucleotide polymorphisms (SNPs) were enrolled. The 10-year Framingham CVD risk score (FRS), IR and MS were evaluated for each subject. Linear regression and logistic regression were utilized to examine the correlations among these variables. RESULTS: After the Benjamini-Hochberg correction, linear regression results indicated positive correlations between variants rs3741297 and rs629301 with FRS (ß = 0.031, PBH=0.002; ß = 0.026, PBH=0.015). Logistic regression revealed that rs3741297 increased MS risk among total subjects [OR = 1.67 (95% CI:1.369-2.038), PBH=1.32 × 10- 5] and increased IR risk in females [OR = 3.475 (95% CI:1.653-7.307), PBH=0.03]. In males, rs2642438 decreased MS risk [OR = 0.81 (95% CI:0.703-0.933), PBH=0.045]. CONCLUSIONS: The rs3741297 variant correlated with susceptibility to CVD, IR, and MS in the OSA population. OSA, CVD, IR and MS share a potentially common genetic background, which may promote precision medicine. CINICAL TRIAL REGISTRATION: The study protocol was registered with the Chinese Clinical Trial Registry (ChiCTR1900025714).

Independent relationship between sleep apnea-specific hypoxic burden and glucolipid metabolism disorder: a cross-sectional study.

OBJECTIVES: Obstructive sleep apnea (OSA) is associated with abnormal glucose and lipid metabolism. However, whether there is an independent association between Sleep Apnea-Specific Hypoxic Burden (SASHB) and glycolipid metabolism disorders in patients with OSA is unknown. METHODS: We enrolled 2,173 participants with suspected OSA from January 2019 to July 2023 in this study. Polysomnographic variables, biochemical indicators, and physical measurements were collected from each participant. Multiple linear regression analyses were used to evaluate independent associations between SASHB, AHI, CT90 and glucose as well as lipid profile. Furthermore, logistic regressions were used to determine the odds ratios (ORs) for abnormal glucose and lipid metabolism across various SASHB, AHI, CT90 quartiles. RESULTS: The SASHB was independently associated with fasting blood glucose (FBG) (ß = 0.058, P = 0.016), fasting insulin (FIN) (ß = 0.073, P < 0.001), homeostasis model assessment of insulin resistance (HOMA-IR) (ß = 0.058, P = 0.011), total cholesterol (TC) (ß = 0.100, P < 0.001), total triglycerides (TG) (ß = 0.063, P = 0.011), low-density lipoprotein cholesterol (LDL-C) (ß = 0.075, P = 0.003), apolipoprotein A-I (apoA-I) (ß = 0.051, P = 0.049), apolipoprotein B (apoB) (ß = 0.136, P < 0.001), apolipoprotein E (apoE) (ß = 0.088, P < 0.001) after adjustments for confounding factors. Furthermore, the ORs for hyperinsulinemia across the higher SASHB quartiles were 1.527, 1.545, and 2.024 respectively, compared with the lowest quartile (P < 0.001 for a linear trend); the ORs for hyper-total cholesterolemia across the higher SASHB quartiles were 1.762, 1.998, and 2.708, compared with the lowest quartile (P < 0.001 for a linear trend) and the ORs for hyper-LDL cholesterolemia across the higher SASHB quartiles were 1.663, 1.695, and 2.316, compared with the lowest quartile (P < 0.001 for a linear trend). Notably, the ORs for hyper-triglyceridemia{1.471, 1.773, 2.099} and abnormal HOMA-IR{1.510, 1.492, 1.937} maintained a consistent trend across the SASHB quartiles. CONCLUSIONS: We found SASHB was independently associated with hyperinsulinemia, abnormal HOMA-IR, hyper-total cholesterolemia, hyper-triglyceridemia and hyper-LDL cholesterolemia in Chinese Han population. Further prospective studies are needed to confirm that SASHB can be used as a predictor of abnormal glycolipid metabolism disorders in patients with OSA. TRIAL REGISTRATION: ChiCTR1900025714 { http://www.chictr.org.cn/ }; Prospectively registered on 6 September 2019; China.

An electrostatic cluster guides Aß40 fibril formation in sporadic and Dutch-type cerebral amyloid angiopathy.

Cerebral amyloid angiopathy (CAA) is associated with the accumulation of fibrillar Aß peptides upon and within the cerebral vasculature, which leads to loss of vascular integrity and contributes to disease progression in Alzheimer's disease (AD). We investigate the structure of human-derived Aß40 fibrils obtained from patients diagnosed with sporadic or familial Dutch-type (E22Q) CAA. Using cryo-EM, two primary structures are identified containing elements that have not been observed in in vitro Aß40 fibril structures. One population has an ordered N-terminal fold comprised of two ß-strands stabilized by electrostatic interactions involving D1, E22, D23 and K28. This charged cluster is disrupted in the second population, which exhibits a disordered N-terminus and is favored in fibrils derived from the familial Dutch-type CAA patient. These results illustrate differences between human-derived CAA and AD fibrils, and how familial CAA mutations can guide fibril formation.

Complete Prevention of Bubbles in a PDMS-Based Digital PCR Chip with a Multifunction Cavity.

In a chamber-based digital PCR (dPCR) chip fabricated with polydimethylsiloxane (PDMS), bubble generation in the chambers at high temperatures is a critical issue. Here, we found that the main reason for bubble formation in PDMS chips is the too-high saturated vapor pressure of water at an elevated temperature. The bubbles should be completely prevented by reducing the initial pressure of the system to under 13.6 kPa to eliminate the effects of increased-pressure water vapor. Then, a cavity was designed and fabricated above the PCR reaction layer, and Parylene C was used as a shell covering the chip. The cavity was used for the negative generator in sample loading, PDMS degassing, PCR solution degassing in the digitization process and water storage in the thermal reaction process. The analysis was confirmed and finally achieved a desirable bubble-free, fast-digitization, valve-free and no-tubing connection dPCR.

The causal relationship between 25-hydroxyvitamin D and serum lipids levels: A bidirectional two-sample mendelian randomization study.

Serum vitamin D levels were linked to lipid metabolism in observational studies, but the exact mechanism was unclear. Several studies have attempted to decipher the relationship between 25(OH)D and lipid levels. Conventional observational studies are vulnerable to confounding. Mendelian randomization (MR) analysis can better control for confounding factors and reverse causality, allowing for the inference of causal association. We, therefore, sought to use MR to investigate the possible causal relationship between 25(OH)D and blood lipid levels (HDL cholesterol, LDL cholesterol, triglycerides, and total cholesterol). A bidirectional two-sample Mendelian randomization (MR) was performed on data primarily from European ancestors. In addition, the potential causal effect of lipids on 25(OH)D was assessed by regressor-based multivariate magnetic resonance (MVMR). The single-nucleotide polymorphisms (SNPs) related to 25(OH)D were selected from a large-scale genome-wide association study (GWAS) database named IEU GWAS, and the SNPs associated with the four blood lipids were chosen from UK Biobank (UKB) lipid GWAS. When blood lipids were the outcome, the results of bidirectional two-sample MR demonstrated that 25(OH)D exhibited a negative causal association with TG, TC, and LDL-C: ß = - 0.23, 95% CI = -0.28 to -0.19, P<0.001; ß = - 0.16, 95% CI: - 0.30 to-0.03, P < 0.05; ß = - 0.11, 95% CI: - 0.23 to 0, P < 0.05. There was no causal relationship between 25(OH)D and HDL-C (ß = 0.05, 95% CI: - 0.11 to 0.20, P = 0.56). When setting blood lipids as exposure, TG and 25(OH)D, ß = -0.13, 95% CI: - 0.15 to -0.10, P < 0.05; TC and 25(OH)D, ß = -0.11, 95% CI: - 0.15 to -0.07, P < 0.05; HDL-C and 25(OH)D, ß = 0.02, 95% CI: 0 to 0.03, P = 0.07; LDL-C and 25(OH)D, ß = -0.08, 95% CI: - 0.11 to -0.05, P < 0.05). Our MVMR study also showed a significant relationship between genetically determined lipid traits and 25(OH)D levels (TG and 25(OH)D, P < 0.05; TC and 25(OH)D, P < 0.05). In all MR analyses, there was no horizontal pleiotropy (all P > 0.05), or statistical heterogeneity. The "Leave-one-out" sensitivity analysis confirmed the stability of our results. MR Studies have shown a bidirectional causal relationship between genetically-determined 25(OH)D levels and serum TG and TC levels. The findings have potential implications for etiological understanding and disease prevention.

The association between functional disability and depressive symptoms among older adults: Findings from the China Health and Retirement Longitudinal Study (CHARLS).

BACKGROUND: Previous research has shown that depressive symptoms in older adults was associated with functional disability, including basic activities of daily living (BADLs) and instrumental activities of daily living (IADLs). However, little is known about the impact of different patterns of functional disability and new-onset functional disability on subsequent depressive symptoms. OBJECTIVE: To determine the effect of various patterns of functional disability and new-onset functional disability on depressive symptoms among Chinese older adults aged 60 years and above. METHOD: The study included 3242 older adults from the China Health and Retirement Longitudinal Study (CHARLS), which was conducted from 2011 to 2018. Cox proportional hazards models were used to investigate the associations between patterns of functional disability and depressive symptoms. The associations were also examined in the population with new-onset functional disability. RESULT: During 15,321 person-years of follow-up, 946 depressive symptoms occurred. The hazard ratios (HRs) of depressive symptoms were 1.29 (95 % confidence intervals [CI]: 1.05-1.58) for IADLs disability, 1.22 (95 % CI: 0.75-1.55) for BADLs disability, and 1.78 (95 % CI: 1.41-2.22) for both IADLs and BADLs disabilities. In the analysis of new-onset functional disability, the HRs were 1.50 (95 % CI: 1.06-2.13) for onset IADLs disability, 1.28 (95 % CI: 0.85-1.91) for onset BADLs disability, and 1.69 (95 % CI: 1.03-2.76) for both onset BADLs and IADLs disabilities. LIMITATIONS: Depressive symptoms were assessed using the Centre for Epidemiological Studies Depression Scale, which has limitations in diagnosing clinical depression. CONCLUSION: Functional disability increases the risk of depressive symptoms, particularly impaired IADLs function. Psychological care for older adults with functional disability should be strengthened.

The association between the maternal pre-pregnancy platelet count and fecundability in mainland China: a population-based cohort study.

BACKGROUND: Currently, awareness about platelet count (PC) and its consequences for perinatal outcome have increased, but there is little reliable evidence on fecundability. METHODS: Based on the National Free Pre-conception Check-up Projects supported by the Chinese government, 5,524,886 couples met the inclusion criteria were included in this cohort study. Cox regression models were adopted to estimate fecundability ratios (FRs) and their 95% confidence intervals for pre-pregnancy PC quintiles. Restricted cubic splines were used to flexibly model and visualize the relationship of PC with FRs. Microsoft SQL server and R software were used for data management and analysis. RESULTS: The median of pre-pregnancy PC among women was 221.00×109/L. The first (<177.00 ×109/L) and second quintile (177.00-207.99 ×109/L) of PC showed slightly increased fecundability (Q1: adjusted FR 1.05, 95% CI 1.04-1.06; Q2: adjusted FR 1.04, 95% CI 1.03-1.05), while higher quintals (Q4: 236.00-271.99 ×109/L; Q5: ≥272.00 ×109/L) were related to reduction of fecundability, when compared with the third quintile of PC (208.00-235.99 ×109/L) (Q4: adjusted FR 0.96, 95% CI 0.95-0.97; Q5: adjusted FR 0.88, 95% CI 0.87-0.89). In the first quintiles (<177.00×109/L), only 20.93% women had PC below 129.94×109/L. An inverse-U shape association was consistently observed among women such that the lower PC of normal range (<118.03×109/L) and higher PC (>223.06×109/L) were associated with the risk of reduced female fecundability (P for non-linearity < 0.01). CONCLUSION: PC is associated with female fecundability. Further classification of PC levels may deepen our understanding of the early warnings and significance of female fecundability.

SPA, a Stigma-style-transmitting tract Physical microenvironment Assay for investigating mechano-signaling in pollen tubes.

Accurate sensing and responding to physical microenvironment are crucial for cell function and survival, but the underlying molecular mechanisms remain elusive. Pollen tube (PT) provides a perfect single-cell model for studying mechanobiology since it's naturally subjected to complex mechanical instructions from the pistil during invasive growth. Recent reports have revealed discrepant PT behaviors between in vivo and flat, two-dimensional in vitro cultures. Here, we established the Stigma-style-transmitting tract (TT) Physical microenvironment Assay (SPA) to recapitulate pressure changes in the pistil. This biomimetic assay has enabled us to swiftly identify highly redundant genes, GEF8/9/11/12/13, as new regulators for maintaining PTs integrity during style-to-TT emergence. In contrast to normal growth on solid medium, SPA successfully phenocopied gef8/9/11/12/13 PT in vivo growth-arrest deficiency. Our results suggest the existence of distinct signaling pathways regulating in vivo and in vitro PT integrity maintenance, underscoring the necessity of faithfully mimicking the physical microenvironment for studying plant cell biology.

The rat frontal orienting field dynamically encodes value for economic decisions under risk.

Frontal and parietal cortex are implicated in economic decision-making, but their causal roles are untested. Here we silenced the frontal orienting field (FOF) and posterior parietal cortex (PPC) while rats chose between a cued lottery and a small stable surebet. PPC inactivations produced minimal short-lived effects. FOF inactivations reliably reduced lottery choices. A mixed-agent model of choice indicated that silencing the FOF caused a change in the curvature of the rats' utility function (U = Vρ). Consistent with this finding, single-neuron and population analyses of neural activity confirmed that the FOF encodes the lottery value on each trial. A dynamical model, which accounts for electrophysiological and silencing results, suggests that the FOF represents the current lottery value to compare against the remembered surebet value. These results demonstrate that the FOF is a critical node in the neural circuit for the dynamic representation of action values for choice under risk.

Expression of bone morphogenetic protein 10 and its role in biomineralization in Hyriopsis cumingii.

Shells and pearls are the products of biomineralization of shellfish after ingesting external mineral ions. Bone morphogenetic proteins (BMPs) play a role in a variety of biological function, and the genes that encode them, are considered important shell-forming genes in mollusks and are associated with shell and pearl formation, embryonic development, and other functions, but bone morphogenetic protein 10 (BMP10) is poorly understood in Hyriopsis cumingii. In this study, we cloned Hc-BMP10 and obtained a 2477 bp full-length sequence encoding 460 amino acids with a conserved TGF-ß structural domain. During the embryonic developmental stages, the cleavage stage had the highest expression of Hc-BMP10, followed by juvenile clams; the expression in the mantle gradually decreased with increasing mussel age. A strong signal was detected on epidermal cells on the mantle edge by in situ hybridization. In both the shell notching and inserting operations of the pearl fragment assay, we found that the expression of Hc-BMP10 increased after the above treatments. RNA interference assays showed that the silencing of Hc-BMP10 resulted in a change in the morphology of the prismatic layer and nacreous layer, with the prismatic layer less closely aligned and the disordered aragonite flakes in the nacreous layer. These findings indicate that Hc-BMP10 is involved in the growth and development of H. cumingii, as well as the formation of shells and pearls. Therefore, this study provides some reference for selecting superior species for growth and pearl breeding of H. cumingii at a molecular level and further investigation of the molecular mechanism for biomineralization of Hc-BMP10.

Study on the Role of Mitophagy Receptor PHB2 in Doubly Uniparental Inheritance of Hyriopsis cumingii.

In bivalves, the heterogeneity of mitochondrial DNA and its unique mode of transmission have been the focus of attention, which is called doubly uniparental inheritance (DUI). Prohibitin-2 (phb2) is a mitochondrial inner membrane protein that is a key mitophagy receptor for parental mitochondrial removal. Hyriopsis cumingii is a freshwater bivalve in China, the full-length cDNA of H. cumingii phb2 (named Hcphb2) is 2917 bp and encodes a total of 300 amino acids, a highly conserved sequence. Hcphb2 was highly expressed in the ovary. In the gonadal tissues of 5- to 8-month-old female mussels, the expression level of Hcphb2 continued to significantly increase. After Hcphb2 siRNA interference in 6-month-old female mussels, the expression of M-COII, a marker gene on M-type mitochondria, showed a considerable increase (p < 0.05). In contrast, the expression of autophagosome formation and maturation-related genes, atg4b, atg5, atg12, and atg16l, in the ATG family genes was significantly decreased (p < 0.01). Subcellular localization showed that Hcphb2 appeared in spermatogonia, spermatocyte, spermatid, and sperm, and its location changes synchronize with the behavior of M-type mitochondria location changes in DUI species. And it was found that miR-184 negatively regulated Hcphb2. The above results suggest that the mitochondrial autophagy receptor gene Hcphb2 may be associated with the degradation of M-type mitochondria in the freshwater mussel. This process requires multiple genes to participate, of which Hcphb2 and autophagy genes are only some of those that may play a role.

Vegetation restoration altered the soil organic carbon composition and favoured its stability in a Robinia pseudoacacia plantation.

Soil organic carbon (SOC) stabilization is vital for the mitigation of global climate change and retention of soil carbon stocks. However, there are knowledge gaps on how SOC sources and stabilization respond to vegetation restoration. Therefore, we investigated lignin phenol and amino sugar biomarkers, SOC physical fractions and chemical structure in one farmland and four stands of a Robinia pseudoacacia plantation. We observed that the content of SOC increased with afforestation, but the different biomarkers had different contributions to SOC. Compared to farmland, the contribution of lignin phenols to SOC decreased in the plantations, whereas there was no difference among the four stand ages, likely resulting from the balance between increasing lignin derivation input and increasing lignin degradation. Conversely, vegetation restoration increased the content of microbial necromass carbon (MNC) and the contribution of MNC to SOC, mainly because microbial residue decomposition was inhibited by decreasing the activity of leucine aminopeptidase, while microbial necromass preservation was promoted by adjusting soil variables (soil water content, clay, pH and total nitrogen). In addition, vegetation restoration increased the particulate organic carbon (POC), mineral-associated organic carbon (MAOC) pools and the O-alkyl C intensify. Overall, vegetation restoration affected SOC composition by regulating lignin phenols and microbial necromass and also altered SOC stabilization by increasing the physically stable MAOC pool during late afforestation. The results of this study suggest that more attention should be given to SOC sequestration and stability during late vegetation restoration.