Heat-stress memory enhances the acclimation of a migratory insect pest to global warming.

In the face of rising global temperatures, the mechanisms behind an organism's ability to acclimate to heat stress remain enigmatic. The rice leaf folder, Cnaphalocrocis medinalis, traditionally viewed as temperature-sensitive, paradoxically exhibits robust larval acclimation to heat stress. This study used the heat-acclimated strain HA39, developed through multigenerational exposure to 39°C during the larval stage, and the unacclimated strain HA27 reared at 27°C to unravel the transgenerational effects of heat acclimation and its regulatory mechanisms. Heat acclimation for larvae incurred a fitness cost in pupae when exposed to high temperature, yet a significant transgenerational effect surfaced, revealing heightened fitness benefit in pupae from HA39, even without additional heat exposure during larval recovery at 27°C. This transgenerational effect exhibited a short-term memory, diminishing after two recovery generations. Moreover, the effect correlated with increased superoxide dismutase (SOD) enzyme activity and expression levels of oxidoreductase genes, representing physiological and molecular foundations of heat acclimation. Heat-acclimated larvae displayed elevated DNA methylation levels, while pupae from HA39, in recovery generations, exhibited decreased methylation indicated by the upregulation of a demethylase gene and downregulation of two methyltransferase genes at high temperatures. In summary, heat acclimation induces DNA methylation, orchestrating heat-stress memory and influencing the expression levels of oxidoreductase genes and SOD activity. Heat-stress memory enhances the acclimation of the migratory insect pest to global warming.

A retrospective study of occlusal reconstruction in patients with old jaw fractures and dentition defects.

PURPOSE: This study evaluated the methods and clinical effects of multidisciplinary collaborative treatment for occlusal reconstruction in patients with old jaw fractures and dentition defects. METHODS: Patients with old jaw fractures and dentition defects who underwent occlusal reconstruction at the Third Affiliated Hospital of Air Force Military Medical University from January 2018 to December 2022 were enrolled. Clinical treatment was classified into 3 phases. In phase I, techniques such as orthognathic surgery, microsurgery, and distraction osteogenesis were employed to reconstruct the correct 3-dimensional (3D) jaw position relationship. In phase II, bone augmentation and soft tissue management techniques were utilized to address insufficient alveolar bone mass and poor gingival soft tissue conditions. In phase III, implant-supported overdentures or fixed dentures were used for occlusal reconstruction. A summary of treatment methods, clinical efficacy evaluation, comparative analysis of imageological examinations, and satisfaction questionnaire survey were utilized to evaluate the therapeutic efficacy in patients with traumatic old jaw fractures and dentition defects. All data are summarized using the arithmetic mean ± standard deviation and compared using independent sample t-tests. RESULTS: In 15 patients with old jaw fractures and dentition defects (an average age of 32 years, ranging from 18 to 53 years), there were 7 cases of malocclusion of single maxillary fracture, 6 of malocclusion of single mandible fracture, and 2 of malocclusion of both maxillary and mandible fractures. There were 5 patients with single maxillary dentition defects, 2 with single mandibular dentition defects, and 8 with both maxillary and mandibular dentition defects. To reconstruct the correct 3D jaw positional relationship, 5 patients underwent Le Fort I osteotomy of the maxilla, 3 underwent bilateral sagittal split ramus osteotomy of the mandible, 4 underwent open reduction and internal fixation for old jaw fractures, 3 underwent temporomandibular joint surgery, and 4 underwent distraction osteogenesis. All patients underwent jawbone augmentation, of whom 4 patients underwent a free composite vascularized bone flap (26.66%) and the remaining patients underwent local alveolar bone augmentation. Free gingival graft and connective tissue graft were the main methods for soft tissue augmentation (73.33%). The 15 patients received 81 implants, of whom 11 patients received implant-supported fixed dentures and 4 received implant-supported removable dentures. The survival rate of all implants was 93.82%. The final imageological examination of 15 patients confirmed that the malocclusion was corrected, and the clinical treatment ultimately achieved occlusal function reconstruction. The patient satisfaction questionnaire survey showed that they were satisfied with the efficacy, phonetics, aesthetics, and comfort after treatment. CONCLUSION: Occlusal reconstruction of old jaw fractures and dentition defects requires a phased sequential comprehensive treatment, consisting of 3D spatial jaw correction, alveolar bone augmentation and soft tissue augmentation, and implant-supported occlusal reconstruction, achieving satisfactory clinical therapeutic efficacy.

The Addition of an Ultra-Small Amount of Black Phosphorous Quantum Dots Endow Self-Healing Polyurethane with a Biomimetic Intelligent Response.

This study explores new applications of black phosphorus quantum dots (BPQDs) by adding them to self-healing material systems for the first time. Self-healing polyurethane with an ultra-small amount of BPQDs has biomimetic intelligent responsiveness and achieves balance between its mechanical and self-healing properties. By adding 0.0001 wt% BPQDs to self-healing polyurethane, the fracture strength of the material increases from 3.0 to 12.3 MPa, and the elongation at break also increases from 750% to 860%. Meanwhile, the self-healing efficiency remains at 98%. The addition of BPQDs significantly improves the deformation recovery ability of the composite materials and transforms the surface of self-healing polyurethane from hydrophilic to hydrophobic, making it suitable for applications in fields such as electronic skin and flexible wearable devices. This study provides a simple and feasible strategy for endowing self-healing materials with biomimetic intelligent responsiveness using a small amount of BPQDs.

Glucose Dehydrogenases-Mediated Acclimation of an Important Rice Pest to Global Warming.

Global warming is posing a threat to animals. As a large group of widely distributed poikilothermal animals, insects are liable to heat stress. How insects deal with heat stress is worth highlighting. Acclimation may improve the heat tolerance of insects, but the underlying mechanism remains vague. In this study, the high temperature of 39 °C was used to select the third instar larvae of the rice leaf folder Cnaphalocrocis medinalis, an important insect pest of rice, for successive generations to establish the heat-acclimated strain (HA39). The molecular mechanism of heat acclimation was explored using this strain. The HA39 larvae showed stronger tolerance to 43 °C than the unacclimated strain (HA27) persistently reared at 27 °C. The HA39 larvae upregulated a glucose dehydrogenase gene, CmGMC10, to decrease the reactive oxygen species (ROS) level and increase the survival rate under heat stress. The HA39 larvae maintained a higher activity of antioxidases than the HA27 when confronted with an exogenous oxidant. Heat acclimation decreased the H2O2 level in larvae under heat stress which was associated with the upregulation of CmGMC10. The rice leaf folder larvae may acclimate to global warming via upregulating CmGMC10 to increase the activity of antioxidases and alleviate the oxidative damage of heat stress.

A foot structure study of new arch flexibility grading system based on three-dimensional arch volume.

PURPOSE: Different arch structures may cause different foot function injuries. In the past, the arch structure and flexibility of the foot were often defined by the height of the arch, and there was no three-dimensional (3D) structure classification method. In order to form a more complete 3D description, we propose a new classification system of arch volume flexibility (AVF), and then use this new classification system to investigate the relationship between the AVF and arch index (AI), and the arch height flexibility (AHF) and AI, respectively. METHODS: It is proposed to recruit 180 young male adults for the test. We obtained arch volume and AI through 3D scanning and obtained the navicular height through manual measurement. Based on these data, we calculated the AHF and the AVF. Using the quintile method, these arches are divided into very stiff, stiff, neutral, flexible, and very flexible. According to AI value, all arches were divided into cavus, rectus, and planus. The distribution of AVF was compared using χ2 goodness of fit test. The spearman correlation test was used to compare the AHF and AVF. A p < 0.05 indicates that the difference is statistically significant. RESULTS: All participants' plantar data was obtained through 3D scanning, but only 159 of them were complete, so only 318 feet had valid data. The left AHF is (21.23 ± 12.91) mm/kN, and the right AHF is (21.71 ± 12.69) mm/kN. The AVF of the left foot arch is (207.35 ± 118.28) mm3/kg, while the right one is (203.00 ± 117.92) mm3/kg, and the total AVF of the arch was (205.17 ± 117.94) mm3/kg. There was no statistical difference in the AVF between the left and right feet for the same participant (n = 159, p = 0.654). In cavus, the percentage of arch with AVF is 21.4% (very stiff), 21.4% (stiff), 14.3% (neutral), 7.1% (flexible), and 35.7% (very flexible). In rectus, the percentage of arch with AVF is 23.9% (very stiff), 19.6% (stiff), 14.7% (neutral), 24.5% (flexible), and 17.2% (very flexible). In planus, the percentage of arch with AVF is 14.9% (very stiff), 20.6% (stiff), 27.0% (neutral), 16.3% (flexible), and 21.3% (very flexible). Moreover, the correlation between AHF and AVF is not significant (p = 0.060). CONCLUSION: In cavus, rectus, and planus, different AVF accounts different percentage, but the difference is not statistically significant. AVF is evenly distributed in the arches of the feet at different heights. We further found the relationship between AHF and AVF is not significant. As a 3D index, AVF may be able to describe the flexibility of the arch more comprehensively than AHF.

Autotetraploid rice: challenges and opportunities.

Autotetraploid rice is a type of germplasm developed from the whole genome duplication of diploid rice, leading to large grains, high nutrient content, and resistance. However, its low fertility has reduced yield and hampered commercialization. To address this issue, a new type of high fertility tetraploid rice was developed, which may serve as a useful germplasm for polyploid rice breeding. In this review, we summarize the progress made in understanding the cellular and molecular genetic mechanisms underlying the low fertility of autotetraploid rice and its F1 hybrid, as well as the main types of new tetraploid rice with high fertility. Lastly, the idea of utilizing the multi-generation heterosis of neo-tetraploid rice in the future is proposed as a reference for polyploid rice breeding.

Clinical Efficacy and Imaging Observation of Three Surgical Approaches in Treatment of Thoracolumbar Fractures.

Objective: To observe the efficacy and imaging of surgical treatment of thoracolumbar fractures via the paravertebral muscle space approach. Methods: A retrospective analysis was conducted on patients with thoracolumbar fractures receiving surgery in Baoding First Central Hospital from January 2019 to December 2020. According to different surgical approaches, they were divided into paravertebral approach group, posterior median approach group and minimally invasive percutaneous approach group. They received surgery via the paravertebral muscle space approach, posterior median approach and minimally invasive percutaneous approach, respectively. Results: Statistically significant differences were found in surgical duration, intraoperative bleeding volume, intraoperative fluoroscopy frequency, postoperative drainage volume and hospital stay among the three groups. One year after surgery, the VAS, ADL and JOA scores of the paravertebral approach group and the minimally invasive percutaneous approach group had statistically significant differences from the posterior median approach group (P < 0.05). Conclusion: For the surgical treatment of thoracolumbar fractures, the clinical efficacy of the paravertebral muscle space approach is superior to that of the traditional posterior median approach, and the clinical efficacy of the minimally invasive percutaneous approach is similar to that of the posterior median approach. All the three approaches can effectively improve the postoperative function and pain symptoms of patients without increasing the incidence of complications. Compared with the posterior median approach, the surgery via the paravertebral muscle space and minimally invasive percutaneous approaches presents shorter surgical duration, less bleeding and shorter hospital stay, which is more conducive to postoperative recovery of patients.

Plant secondary metabolite and temperature determine the prevalence of Arsenophonus endosymbionts in aphid populations.

Transmission rate and role in hosts contribute to the prevalence of an endosymbiont. However, factors affecting transmission and role of facultative endosymbionts are still not well understood. Here, we illustrated that host plants and environmental temperatures affected the transmission, relative abundance and role of Arsenophonus in the cotton aphid Aphis gossypii. The transmission rate of this endosymbiont from mother aphids to offspring was relatively lower. High temperatures impeded the transmission, and infection rates declined as aphids were exposed to 30°C. Contents of amino acids and secondary metabolites were remarkably different among host plants. Aphids feeding on zucchini leaves containing a higher titre of amino acids and lower secondary metabolites harboured a relatively lower abundance of Arsenophonus. Concentrations of an amino acid and a plant secondary metabolite, cucurbitacin B, in aphid diet were not associated with Arsenophonus abundance. However, gossypol, another plant secondary metabolite, was strongly related with the abundance. Arsenophonus imparted a fitness benefit to aphids, and the benefit was dependent on host plants and gossypol concentration. In sum, plant secondary metabolite and environmental temperature affect transmission, relative abundance and role of Arsenophonus, which determine the endosymbiont prevalence in aphid populations.

Cuticular protein genes involve heat acclimation of insect larvae under global warming.

Cuticular proteins (CPs) play important roles in insect growth and development. However, it is unknown whether CPs are related to heat tolerance. Cnaphalocrocis medinalis, a serious pest of rice, occurs in summer and exhibits strong adaptability to high temperature, but the underlying mechanism is unclear. Here, the role of CP genes in heat acclimation was studied. Heat tolerance of the heat-acclimated larvae was significantly stronger than the unacclimated larvae. The cuticular protein content in the heat-acclimated larvae was higher than that of the unacclimated larvae. 191 presumed CP genes of C. medinalis (CmCPs) were identified. Expression patterns of 14 CmCPs were different between the heat acclimated (S39) and unacclimated (S27) larvae under heat stress. CmCPs were specifically expressed in epidermis and the head except CmCPR20 mainly expressed in Malpighian tubules. CmCPR20 was upregulated in S39 while downregulated in S27, but CmTweedle1 and CmCPG1 were upregulated in S27 and downregulated in S39. RNAi CmTweedle1 or CmCPG1 remarkably decreased heat tolerance and cuticular protein content of the heat-acclimated larvae but not the unacclimated larvae. RNAi CmCPR20 decreased heat tolerance and cuticular protein content of the unacclimated larvae but not the heat-acclimated larvae. CmTweedle1 and CmCPG1 genes involve heat acclimation of C. medinalis.

Primary tuberculous granuloma in the falciform ligament of liver.

Isolated tuberculous granuloma in the falciform ligament of the liver has never been reported. Here, we report a case of tuberculous granuloma in the falciform ligament of the liver of a 45-year-old woman who complained only of persistent right upper abdominal pain. On abdominal contrast-enhanced CT and MRI, it is difficult to distinguish benign from malignant masses. Imaging on 18 F-FDG PET/CT showed high uptake of 18 F-FDG in the lesion, which was thus considered more likely to be malignant. However, postoperative pathological examination showed granulomatous inflammation with caseous necrosis, which was diagnosed as tuberculosis.

Hydrogel-Mediated Mineralization Generates Oriented Crystalline Films Comprising Granular-Rhombohedral Heterogeneous Structures.

Gel-mediated crystallization is a common system to produce self-organized materials, which is fundamental to the development of bottom-up approaches to functional complex materials. Mineralization in hydrogel matrices nevertheless remains empirical in the generation of crystallization products with tailored heterogeneous structures. We demonstrate that the employment of the hydrogels with proper cationic diffusivity can trigger the consecutive growth of oriented, granular-rhombohedral heterogeneous structures. The controllable morphogenesis leads to continuous calcitic CaCO3 films comprising spatial heterogeneity, where epitaxial match assumedly favors the successive deposition of both granular and rhombohedral layers. The scenario of consecutive growth is disclosed, where the thickness of the granular layers can become a valuable indicator to reflect the retardancy degree of crystallization. The evaluation of the physicochemical properties of the hydrogels finally establishes a direct correlation between the cationic diffusivity of the hydrogels and the appearance of the heterogeneous structures. The current work therefore sheds light on the implementation of rational morphogenetic approaches to crystalline materials with tailored complex architectures.

Comparative transcriptome analysis of the rice leaf folder (Cnaphalocrocis medinalis) to heat acclimation.

BACKGROUND: The rice leaf folder Cnaphalocrocis medinalis Güenée is a serious insect pest of rice in Asia. This pest occurs in summer, and it is sensitive to high temperature. However, the larvae exhibit heat acclimation/adaptation. To understand the underlying mechanisms, we established a heat-acclimated strain via multigenerational selection at 39 °C. After heat shock at 41 °C for 1 h, the transcriptomes of the heat-acclimated (S-39) and unacclimated (S-27) larvae were sequenced, using the unacclimated larvae without exposure to 41 °C as the control. RESULTS: Five generations of selection at 39 °C led larvae to acclimate to this heat stress. Exposure to 41 °C induced 1160 differentially expressed genes (DEGs) between the heat-acclimated and unacclimated larvae. Both the heat-acclimated and unacclimated larvae responded to heat stress via upregulating genes related to sensory organ development and structural constituent of eye lens, whereas the unacclimated larvae also upregulated genes related to structural constituent of cuticle. Compared to unacclimated larvae, heat-acclimated larvae downregulated oxidoreductase activity-related genes when encountering heat shock. Both the acclimated and unacclimated larvae adjusted the longevity regulating, protein processing in endoplasmic reticulum, antigen processing and presentation, MAPK and estrogen signaling pathway to responsed to heat stress. Additionally, the unacclimated larvae also adjusted the spliceosome pathway, whereas the heat-acclimated larvae adjusted the biosynthesis of unsaturated fatty acids pathway when encountering heat stress. Although the heat-acclimated and unacclimated larvae upregulated expression of heat shock protein genes under heat stress including HSP70, HSP27 and CRYAB, their biosynthesis, metabolism and detoxification-related genes expressed differentially. CONCLUSIONS: The rice leaf folder larvae could acclimate to a high temperature via multigenerational heat selection. The heat-acclimated larvae induced more DEGs to response to heat shock than the unacclimated larvae. The changes in transcript level of genes were related to heat acclimation of larvae, especially these genes in sensory organ development, structural constituent of eye lens, and oxidoreductase activity. The DEGs between heat-acclimated and unacclimated larvae after heat shock were enriched in the biosynthesis and metabolism pathways. These results are helpful to understand the molecular mechanism underlying heat acclimation of insects.

Efficacy of occlusal splints in the treatment of temporomandibular disorders: a systematic review of randomized controlled trials.

OBJECTIVE: This systematic review aimed to assess the efficacy of occlusal splints in the treatment of temporomandibular disorders (TMDs). MATERIAL AND METHODS: This systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Four databases (Medline via Pubmed, Web of Science, Embase and Scopus) were searched, the last search was conducted on April 2020. Randomised controlled trials (RCTs) employing the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) or Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) as diagnostic criteria and including occlusal splint as one of the experimental groups were included in the present study. The data from the included studies were extracted and assessed for risk of bias. RESULTS: Eleven studies were included. The sample size ranged from 12 to 96 subjects. The male to female ratio was 0 to 25%. The mean length of follow-up was 4 months. Occlusal splint had a positive effect on mandibular movements in all included studies. Seven studies showed a positive effect of occlusal splint on chronic pain reduction and pain intensity, while two others showed improvement of temporomandibular joint clicking sounds and locking of the jaws. Moreover, improvements in mouth opening, depression, and anxiety symptoms, were reported in four studies. CONCLUSIONS: An occlusal splint can be considered as a non-invasive treatment approach for patients with TMD, especially those with signs and symptoms of restriction of mandibular movement and pain. Moreover, the present findings highlighted an urgent need of a standardised consensus regarding the prognostic evaluation of TMD.

Infections with Arsenophonus Facultative Endosymbionts Alter Performance of Aphids (Aphis gossypii) on an Amino-Acid-Deficient Diet.

Genetic polymorphism and endosymbiont infection are ubiquitous in aphid populations. It has been known that the obligate symbiont Buchnera provides aphids with essential amino acids which cannot be ingested from plant sap. Buchnera often coexists with facultative endosymbionts in aphids. However, it is unclear whether the facultative endosymbionts affect the aphid's amino acid requirements from diet. In this study, we found that the facultative endosymbiont status in populations of the cotton-melon aphid Aphis gossypii was associated with aphid genotype or host plant. The infection frequency of Arsenophonus in aphids living on cotton was significantly higher than that in aphids on cucumber, and cucumber leaves contained higher titers of free amino acids than cotton leaves, especially amino acids Leu, Arg, Ile, Val, and Phe. The net reproductive rates of five aphid genotypes infected with Arsenophonus were not different on the complete-amino-acid diet, but the values were significantly different among seven Arsenophonus-free aphid genotypes. Moreover, the net reproductive rates of aphids on the amino-acid-deficient diet were significantly affected by Arsenophonus infection and aphid genotype. Arsenophonus infection decreased aphid performance on the Phe-free diet but improved performance on the Leu-free diet and did not affect the performance on the Ile-free or Val-free diet. Arsenophonus infections altered aphid requirements for amino acids that were significantly different in cotton and cucumber leaves, suggesting this endosymbiont would modulate the host specialization of this aphid.IMPORTANCE The facultative endosymbiont Arsenophonus plays an important role in regulating reproduction through son killing, enemy resistance, and the dietary breadth of its insect hosts. In this study, we found Arsenophonus could alter aphid performance on the amino-acid-deficient diets. Arsenophonus infection increased aphid requirements for the amino acid Phe, but decreased requirements for the Leu. Cotton and cucumber leaves contained drastically different titers of free amino acids Phe and Leu, and aphids living on these two plants were infected with different incidences of Arsenophonus We hypothesize that host specialization or the host plant range of aphids may be mediated by Arsenophonus.

Study of biodegradable occluder of atrial septal defect in a porcine model.

OBJECTIVE: To evaluate the safety and feasibility of a modified poly(l-lactic acid) (PLLA) atrial septal defect (ASD) occluder. METHODS: Forty-five piglets were divided into two groups: an experimental group (n = 27) and a control group (n = 18). The experimental group underwent percutaneous implantation of a modified PLLA ASD device while the control group underwent percutaneous implantation of a widely used metal ASD device. X-ray imaging, transthoracic echocardiography (TTE), electrocardiogram (ECG), histopathology and electron microscopic examination were performed at 7 days, 1, 3, 6, and 12 months after implantation. RESULTS: Twenty-seven experimental piglets and 18 control piglets were all successfully implanted with modified biodegradable and metal ASD devices, respectively. While both devices exhibited very good occluding effects, the modified PLLA ASD devices were completely endothelialized at 3 months after implantation, and the endothelialization appeared to be more complete compared to the control group. Degradation of the PLLA devices was noted at 12 months follow-up with no loss of integrity at the atrial septum. CONCLUSION: This animal model with implanting of the occluders was effective and not associated with complications. The modified PLLA ASD devices are more controllable and practical than our previous devices. The implanted devices demonstrated good endothelialization and degradability in short and moderate term follow-up. Long-term studies are now underway to further evaluate the biodegradability of this novel device.

Sensitivity of a Ratio Vegetation Index Derived from Hyperspectral Remote Sensing to the Brown Planthopper Stress on Rice Plants.

Remote sensing end-products related to vegetation have potential applications in monitoring the health of crops. The sensitivity of a spectral index to crop stress determines its application prospect. Our aim in this study was to explore the sensitivity of a ratio vegetation index (RVI) to identify the damage caused by brown planthoppers (BPHs) on rice plants, and to evaluate the potential application of hyperspectral end-products to monitor population size of BPH. Different numbers of the second-instar nymphs were released onto potted rice at the tillering stage. The plants were exposed to BPH for two, four, six, and eight days, and reflectance from the damaged rice was measured using a hyperspectral spectroradiometer. Measurements were done again two, four, and six days after exposure (recover days), and then the spectral index RVI746/670 was compared among rice plants infested with different numbers of BPH. The relationships between RVI746/670, the number of BPH and exposure day were simulated by linear and curve models. BPH damage resulted in a decreased spectral index RVI746/670 of rice plants. RVI746/670 well indicated the damage of rice plants caused by six⁻eight BPH nymphs per plant in six⁻eight days, but the index could not identify the damage of these nymphs in two days. The RVI746/670 showed a two⁻four-day delay to indicate a slight BPH damage. The spectral index RVI746/670 could indicate the physiologic compensation of plants for the feeding of BPH and the post-effect of BPH damage on rice. The RVI746/670 of rice showed a quadratic curve relation with the number of BPH nymphs and a quadratic or linear relation with the exposure day. The recover day had no significant effects on RVI746/670. The RVI746/670 (Y) could be simulated by a quadratic surface model based on the number of BPH (N) and exposure day (T): Y = 3.09427 + 0.59111T + 0.44296N - 0.03683T² - 0.03035N² - 0.08188NT (R² = 0.5228, p < 0.01). In summary, the spectral index RVI746/670 of rice is sensitive to damage caused by BPH.

Multigenerational heat acclimation increases thermal tolerance and expression levels of Hsp70 and Hsp90 in the rice leaf folder larvae.

Physiological response and acclimation to thermal stress is a key strategy of insects to cope with changing climate. The underlying mechanism of heat acclimation in insects is still unclear. Here, the heat selection and transcript level response in the larvae of the rice leaf folder Cnaphalocrocis medinalis Güenée, a serious pest of rice in summer, were studied. The survival and fecundity of larvae during multigenerational heat selection at 39 °C were examined, and heat tolerance and mRNA expression of heat shock protein 70 (Hsp70) and 90 (Hsp90) were examined under heat stress. The results showed that survival and fecundity of larvae increased notably and then kept constant after two or three generations of heat selection. Heat selection improved thermal tolerance of larvae. The Hsp70 mRNA expression of the 3rd-instar larvae increased in all five generations of heat selection, but Hsp90 increased only in the first two generations. The response of Hsp70 to 39 °C heat treatment in the larvae kept at 27 °C was different from the larvae exposed to the conditioning heat treatments, but the response of Hsp 90 was similar. Moreover, the Hsp70 and Hsp90 mRNA expression levels were significantly higher in the heat-acclimated larvae than that in the unacclimated larvae at a comparable duration of exposure to 37 and 41 °C. Selection at a high temperature across multiple generations led larvae to heat acclimation, and Hsp70 and Hsp90 were involved in this acclimation process.

[The effect of lncRNA TCONS_00815878 on differentiation of porcine skeletal muscle satellite cells].

Porcine skeletal muscle development is a complex biological process, and differentiation of skeletal muscle satellite cells is an important part of skeletal muscle development. In recent years, it has been found that lncRNA plays an important role in the differentiation of skeletal muscle satellite cells. Here we investigate the effect of lncRNA TCONS_00815878 on the differentiation of porcine skeletal muscle satellite cells. We first used qRT-PCR to detect the expression levels of TCONS_00815878 in six tissues (heart, spleen, lung, kidney, back muscles and leg muscles) of Yorkshire piglets within seven days of birth. At the same time, the expression levels of TCONS_00815878 at five different time points from the embryonic stage to the postnatal stage (35 d, 45 d, 55 d of embryos, and 7 d, 200 d of postpartum leg muscles) were examined. The expression of the differentiation marker genes MyoD, MyoG and MyHC was examined by knocking down TCONS_00815878 in porcine skeletal muscle satellite cells using antisense oligonucleotides (ASO). The target gene of TCONS_00815878 was predicted by bioinformatics analysis, and the function and pathway of its target gene were predicted online using DAVID software. The results showed that TCONS_00815878 had the highest expression level in pig myocardium and leg muscles. Within seven days after birth, TCONS_00815878 increased in the muscle tissue of pigs, and reached the peak of expression level on the 7th day. During the process of proliferation and differentiation of porcine skeletal muscle satellite cells, the expression level of TCONS_00815878 increased during the differentiation stage and peaked at 30 h of differentiation. After knocking down TCONS_00815878, the expression levels of MyoD, MyoG and MyHC were decreased, but the expression level of MyoD was significantly decreased (P<0.05). In addition, functional predictions revealed that the target gene of TCONS_00815878 is enriched in multiple biological processes, such as glycolysis and pyruvate metabolism, related to skeletal muscle satellite cell differentiation. This study speculates that lncRNA TCONS_00815878 may promote the differentiation of porcine skeletal muscle satellite cells.

Autotetraploid rice methylome analysis reveals methylation variation of transposable elements and their effects on gene expression.

Polyploidy, or whole-genome duplication (WGD), serves as a key innovation in plant evolution and is an important genomic feature for all eukaryotes. Neopolyploids have to overcome difficulties in meiosis, genomic alterations, changes of gene expression, and epigenomic reorganization. However, the underlying mechanisms for these processes are poorly understood. One of the most interesting aspects is that genome doubling events increase the dosage of all genes. Unlike allopolyploids entangled by both hybridization and polyploidization, autopolyploids, especially artificial lines, in relatively uniform genetic background offer a model system to understand mechanisms of genome-dosage effects. To investigate DNA methylation effects in response to WGD rather than hybridization, we produced autotetraploid rice with its diploid donor, Oryza sativa ssp. indica cv. Aijiaonante, both of which were independently self-pollinated over 48 generations, and generated and compared their comprehensive transcriptomes, base pair-resolution methylomes, and siRNAomes. DNA methylation variation of transposable elements (TEs) was observed as widespread in autotetraploid rice, in which hypermethylation of class II DNA transposons was predominantly noted in CHG and CHH contexts. This was accompanied by changes of 24-nt siRNA abundance, indicating the role of the RNA-directed DNA methylation pathway. Our results showed that the increased methylation state of class II TEs may suppress the expression of neighboring genes in autotetraploid rice that has obtained double alleles, leading to no significant differences in transcriptome alterations for most genes from its diploid donor. Collectively, our findings suggest that chromosome doubling induces methylation variation in TEs that affect gene expression and may become a "genome shock" response factor to help neoautopolyploids adapt to genome-dosage effects.

Autophagy was involved in the protective effect of metformin on hyperglycemia-induced cardiomyocyte apoptosis and Connexin43 downregulation in H9c2 cells.

Background: Increased cardiomyocyte apoptosis under high glucose condition contributes to diabetic cardiomyopathy. Degradation of cardiac Connexin43 (Cx43) has been associated with cardiac dysfunction in diabetic heart. Clinical and experimental studies suggested that metformin (Met) exhibits cardioprotective properties against diabetes. Aim: The aim of this study was to investigate the effect and underlying signaling mechanisms of metformin on apoptosis and Cx43 expression in H9c2 cells presenting with hyperglycemia conditions. Methods: In the present study, H9c2 cardiac cells were incubated with 5.5 mM glucose, 33.3 mM glucose, 33.3 mM glucose with metformin at two dose (100 µM, 1 mM) for 96 hours, and 1 mM metformin with chloroquine (50 µM) in 33.3 mM glucose medium. Cell viability was determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) cell survival assay. Cytotoxicity was determined by the release of lactate dehydrogenase (LDH). The expression of Cx43, autophagic maker protein (LAMP-1, Beclin-1, p62 and LC3) and apoptosis maker protein (Bcl-2 and Bax) were determined by western blot. Results: The results showed that high glucose increased apoptosis and decreased Cx43 expression. Interestingly, metformin attenuated hyperglycemia-increased apoptosis and restored Cx43 expression. Moreover, this treatment caused autophagy as well, which indicated by up-regulation of autophagy-related proteins LAMP-1, Beclin-1, p62 and reduction in the ratio of LC3-II/LC3-I. In addition, administration autophagy inhibitor chloroquine (CQ) did not block the effect of metformin on Cx43 expression while increasing Cx43 content, together with an increased apoptosis. Conclusion: Administration metformin can protect the H9c2 cells against hyperglycemia-induced apoptosis and Cx43 down-regulation, in part, mediated through the induction of autophagy pathway.