Fertility history and intentions of married women, China.

Objective: To estimate the proportion of married women in China who intend to become pregnant given the country's pronatalist population policy and to investigate fecundity, with an emphasis on the influence of socioeconomic factors. Methods: A nationally representative survey of 12 815 married women aged 20 to 49 years (mean: 36.8 years) was conducted during 2019 and 2020. All completed questionnaires, 10 115 gave blood samples and 11 710 underwent pelvic ultrasound examination. Fertility intention was the desire or intent to become pregnant combined with engagement in unprotected sexual intercourse. We defined infertility as the failure to achieve pregnancy after 12 months or more of unprotected intercourse. We considered an anti-Müllerian hormone level < 1.1 ng/mL and an antral follicular count < 7 as indicating an abnormal ovarian reserve. Findings: Fertility intentions were reported by 11.9% of women overall but by only 6.1% of current mothers (weighted percentages). Fertility intention was significantly less likely among women in metropolises (odds ratio, OR: 0.38; 95% confidence interval, CI: 0.31-0.45) and those with a higher educational level (OR: 0.74; 95% CI: 0.62-0.88). Overall, 18.0% had experienced infertility at any time and almost 30% had an abnormal ovarian reserve on assessment. An abnormal ovarian reserve and infertility were less likely in women in metropolises (P < 0.05) but more likely in obese women (P < 0.05). Conclusion: The willingness of Chinese married women to give birth remained low, even with relaxation of the one-child policy.

Nanoassemblies of heptamethine cyanine dye-initiated poly(amino acid) enhance ROS generation for effective antitumour phototherapy.

Phototherapy shows great potential for pinpoint tumour treatment. Heptamethine cyanine dyes like IR783 have high potential as agents for antitumour phototherapy due to their inherent tumour targeting ability, though their effectiveness in vivo is unsatisfactory for clinical translation. To overcome this limitation, we present an innovative strategy involving IR783-based polymeric nanoassemblies that improve the dye's performance as an antitumoural photosensitizer. In the formulation, IR783 is modified with cysteamine and used to initiate the ring-opening polymerization (ROP) of the N-carboxyanhydride of benzyl-L-aspartate (BLA), resulting in IR783-installed poly(BLA). Compared to free IR783, the IR783 dye in the polymer adopts a twisted molecular conformation and tuned electron orbital distribution, remarkably enhancing its optical properties. In aqueous environments, the polymers spontaneously assemble into nanostructures with 60 nm diameter, showcasing surface-exposed IR783 dyes that function as ligands for cancer cell and mitochondria targeting. Moreover, the nanoassemblies stabilized the dyes and enhanced the generation of reactive oxygen species (ROS) upon laser irradiation. Thus, in murine tumor models, a single injection of the nanoassemblies with laser irradiation significantly inhibits tumour growth with no detectable off-target toxicity. These findings highlight the potential for improving the performance of heptamethine cyanine dyes in antitumor phototherapy through nano-enabled strategies.

Selective Intracellular Delivery of Antibodies in Cancer Cells with Nanocarriers Sensing Endo/Lysosomal Enzymatic Activity.

The differential enzymatic activity in the endo/lysosomes of particular cells could trigger targeted endosomal escape functions, enabling selective intracellular protein delivery. However, this strategy may be jeopardized due to protein degradation during endosomal trafficking. Herein, using custom made fluorescent probes to assess the endosomal activity of cathepsin B (CTSB) and protein degradation, we found that certain cancer cells with hyperacidified endosomes grant a spatiotemporal window where CTSB activity surpass protein digestion. This inspired the engineering of antibody-loaded polymeric nanocarriers having CTSB-activatable endosomal escape ability. The nanocarriers selectively escaped from the endo/lysosomes in the cells with high endosomal CTSB activity and delivered active antibodies to intracellular targets. This study provides a viable strategy for cell-specific protein delivery using stimuli-responsive nanocarriers with controlled endosomal escape.

Ionizable Polymeric Micelles with Phenylalanine Moieties Enhance Intracellular Delivery of Self-Replicating RNA for Long-Lasting Protein Expression In Vivo.

mRNA-based therapeutics are revolutionizing the landscape of medical interventions. However, the short half-life of mRNA and transient protein expression often limits its therapeutic potential, demanding high treatment doses or repeated administrations. Self-replicating RNA (RepRNA)-based treatments could offer enhanced protein production and reduce the required dosage. Here, we developed polymeric micelles based on flexible poly(ethylene glycol)-poly(glycerol) (PEG-PG) block copolymers modified with phenylalanine (Phe) moieties via biodegradable ester bonds for the efficient delivery of RepRNA. These polymers successfully encapsulated RepRNA into sub-100 nm micelles assisted by the hydrophobicity of the Phe moieties and their ability to π-π stack with the bases in RepRNA. The micelles made from Phe-modified PEG-PG (PEG-PG(Phe)) effectively maintained the integrity of the loaded RepRNA in RNase-rich serum conditions. Once taken up by cells, the micelles triggered a pH-responsive membrane disruption, promoted by the strong protonation of the amino groups at endosomal pH, thereby delivering the RepRNA to the cytosol. The system induced strong protein expression in vitro and outperformed commercial transfecting reagents in vivo, where it resulted in enhanced and long-lasting protein expression.

An update on renal fibrosis: from mechanisms to therapeutic strategies with a focus on extracellular vesicles.

The increasing prevalence of chronic kidney disease (CKD) is a major global public health concern. Despite the complicated pathogenesis of CKD, renal fibrosis represents the most common pathological condition, comprised of progressive accumulation of extracellular matrix in the diseased kidney. Over the last several decades, tremendous progress in understanding the mechanism of renal fibrosis has been achieved, and corresponding potential therapeutic strategies targeting fibrosis-related signaling pathways are emerging. Importantly, extracellular vesicles (EVs) contribute significantly to renal inflammation and fibrosis by mediating cellular communication. Increasing evidence suggests the potential of EV-based therapy in renal inflammation and fibrosis, which may represent a future direction for CKD therapy.

An IL-12-Based Nanocytokine Safely Potentiates Anticancer Immunity through Spatiotemporal Control of Inflammation to Eradicate Advanced Cold Tumors.

Treatment of immunologically cold tumors is a major challenge for immune checkpoint inhibitors (ICIs). Interleukin 12 (IL-12) can invigorate ICIs against cold tumors by establishing a robust antitumor immunity. However, its toxicity and systemic induction of counteracting immunosuppressive signals have hindered translation. Here, IL-12 activity is spatiotemporally controlled for safely boosting efficacy without the stimulation of interfering immune responses by generating a nanocytokine that remains inactive at physiological pH, but unleashes its full activity at acidic tumor pH. The IL-12-based nanocytokine (Nano-IL-12) accumulate and release IL-12 in tumor tissues, eliciting localized antitumoral inflammation, while preventing systemic immune response, counteractive immune reactions, and adverse toxicities even after repeated intravenous administration. The Nano-IL-12-mediated spatiotemporal control of inflammation prompt superior anticancer efficacy, and synergize with ICIs to profoundly inflame the tumor microenvironment and completely eradicate ICI-resistant primary and metastatic tumors. The strategy could be a promising approach toward safer and more effective immunotherapies.

Dietary Methylglyoxal Exposure Induces Alzheimer's Disease by Promoting Amyloid ß Accumulation and Disrupting Autophagy in Caenorhabditis elegans.

Methylglyoxal (MG) is a precursor of advanced glycation end products usually generated during cooking. The high level of MG in the brain is correlated to the pathogenesis of Alzheimer's disease (AD). However, it is not clear if MG consumed through the diet can cause AD-related toxicity. Herein, the Caenorhabditis elegans (C. elegans) AD model was used to investigate the neurotoxicity after long-term MG exposure at dietary levels. The results showed that C. elegans locomotive behaviors were significantly decreased after 0.1, 0.5, and 1 mM MG exposure (p < 0.001). In amyloid ß (Aß)-expressing transgenic C. elegans strains, 0.5 mM MG significantly promoted Aß accumulation by around 50% in day-8 CL2006 (p < 0.001), enhanced paralysis in CL4176 (p < 0.001) and CL2006 (p < 0.01), and made CL2355 around 17% more vulnerable to 5-HT, indicating impaired serotonin reuptake (p < 0.05). Additionally, 0.5 mM MG significantly increased the reactive oxygen species level (p < 0.001) by inhibiting the expression of stress-response genes including sod-3, gst-4, and hsp-16.2 in day-8 aged worms. Moreover, the autophagic pathway was disrupted through lgg-1, vps-34, and bec-1 expression after MG exposure and Aß accumulation. Treatment with the citrus flavonoid nobiletin reduced the MG-induced toxicity (p < 0.001). Overall, these findings imply that it is possible to exacerbate AD pathogenesis by MG exposure through the diet.

Age-specific random day serum antimüllerian hormone reference values for women of reproductive age in the general population: a large Chinese nationwide population-based survey.

BACKGROUND: Antimüllerian hormone, the most reliable biomarker of ovarian reserve, is widely used in various clinical situations. Antimüllerian hormone levels consistently decrease with age. However, there is no standard, age-specific reference values for antimüllerian hormone in women of reproductive age, which limits its application. OBJECTIVE: This study aimed to establish age-specific antimüllerian hormone percentile reference values for women of reproductive age. STUDY DESIGN: A nationwide, population-based cross-sectional survey was conducted between May 2019 and April 2021 in 15 provinces and municipalities in mainland China. A total of 10,053 eligible women aged 20 to 49 years were selected using a multistage stratified sampling procedure. Women who were pregnant, had undergone ovarian surgery, took hormone drugs in the past 3 months, or had an antimüllerian hormone outlier value were excluded from establishing antimüllerian hormone percentile reference values. Serum antimüllerian hormone concentrations were measured using ultrasensitive, 2-site enzyme-linked immunosorbent assays (Ansh Lab, Webster, TX) in the Reproductive Endocrinology Laboratory of Peking University Third Hospital. Generalized additive models for location scale and shape with the Box-Cox t original distribution were used to estimate the fitted antimüllerian hormone percentile reference values. RESULTS: A total of 9112 eligible women aged 21 to 49 years were included in the fitting model. The fitted 50th (2.5th-97.5th) percentiles of antimüllerian hormone values for women aged 21, 25, 30, 35, 40, 45, and 49 years were 4.83 (0.79-18.41), 4.47 (0.72-16.58), 3.67 (0.50-13.82), 2.59 (0.24-10.35), 1.35 (0.05-6.68), 0.33 (<0.01 to 3.40), and 0.04 (<0.01 to 1.77) ng/mL, respectively. The population-based decline rate of antimüllerian hormone accelerated with increasing age, especially age >35 years. The magnitude of the decline of the 25th antimüllerian hormone percentile curve was greater than that of the 75th percentile curve. CONCLUSION: This study established age-specific antimüllerian hormone percentile reference values for women of reproductive age based on a large representative sample of the general population and described antimüllerian hormone changes. These findings may facilitate antimüllerian hormone application in clinical practices.

Changes in the prevalence of polycystic ovary syndrome in China over the past decade.

Background: Polycystic ovary syndrome (PCOS) has become a major international public health concern. However, because of controversy about the diagnostic criteria and patient selection, estimates of its absolute prevalence and change with time vary greatly. Methods: We conducted two consecutive nationwide epidemiological surveys of the prevalence of PCOS in representative samples of reproductive-aged women in China in 2010 and 2020. Face-to-face interviews were performed by trained interviewers in each survey. All participants completed a questionnaire and underwent a physical examination, blood sampling, and transvaginal pelvic ultrasound. We assessed hyperandrogenism (H), chronic anovulation (O), and polycystic ovaries (P) to classify the presence of PCOS using the Rotterdam criteria. The prevalence of PCOS among reproductive-aged women was estimated after consideration of differential probabilities of selection and population distribution. We conducted a logistic regression analysis by using the probability of PCOS as a function of the survey year to acquire the trend information across the years. Findings: 28,739 respondents completed the survey, including 15,924 in the previously published 2010 survey and 12,815 in the new 2020 survey. In 2020, 826 participants could be diagnosed as having PCOS, with a weighted prevalence of 7.8% (95%CI: 7.0%, 9.0%) among women aged 20-49 years, leading to an estimate of 24.0 million women of reproductive age affected by this condition in China as a whole. The estimated prevalence in 2020 was higher than that of a decade ago despite identical research methods suggesting a two-thirds increase over the study period. Women with PCOS in 2020 also appeared to have a more severe phenotype overall than those of a decade ago, possibly reflecting a significantly higher prevalence of obesity, hyperandrogenism, and infertility. Interpretation: The prevalence of PCOS in Chinese women has increased significantly over the past 10 years. PCOS is a significant public health problem in women of reproductive age in China and national policy and guidelines should be re-examined in the light of the current data. Funding: National Key R&D Program of China and the National Natural Science Foundation of China.

Identification and Characterization of a Double-Stranded RNA Degrading Nuclease Influencing RNAi Efficiency in the Rice Leaf Folder Cnaphalocrocis medinalis.

Rice leaf folder Cnaphalocrocis medinalis is one of the most serious pests of rice in rice-planting regions worldwide. DsRNA-degrading nucleases (dsRNases) are important factors in reducing the efficiency of RNA interference (RNAi) in different insects. In this study, a dsRNase gene from C. medinalis (CmdsRNase) was cloned and characterized. The CmdsRNase cDNA was 1395 bp in length, encoding 464 amino acids. The CmdsRNase zymoprotein contains a signal peptide and an endonuclease NS domain that comprises six active sites, three substrate-binding sites, and one Mg2+-binding site. The mature CmdsRNase forms a homodimer with a total of 16 α-helices and 20 ß-pleated sheets. Homology and phylogenetic analyses revealed that CmdsRNase is closely related to dsRNase2 in Ostrinia nubilalis. Expression pattern analysis by droplet digital PCR indicated that the expression levels of CmdsRNase varied throughout the developmental stages of C. medinalis and in different adult tissues, with the highest expression levels in the fourth-instar larvae and the hemolymph. CmdsRNase can degrade dsRNA to reduce the efficiency of RNAi in C. medinalis. Co-silencing of CmCHS (chitin synthase from C. medinalis) and CmdsRNase affected significantly the growth and development of C. medinalis and thus improved RNAi efficacy, which increased by 27.17%. These findings will be helpful for green control of C. medinalis and other lepidopteran pests by RNAi.

Identification and Functional Analysis of a Defensin CcDef2 from Coridius chinensis.

Coridius chinensis belongs to Dinidoridae, Hemiptera. Previous studies have indicated that C. chinensis contains abundant polypeptides with antibacterial and anticancer activities. Antimicrobial peptides (AMPs), as endogenous peptides with immune function, play an indispensable role in the process of biological development and immunity. AMPs have become one of the most potential substitutes for antibiotics due to their small molecular weight and broad-spectrum antimicrobial activity. In this study, a defensin CcDef2 from C. chinensis was characterized based on bioinformatics and functional analyses. The mature peptide of CcDef2 is a typical cationic peptide composed of 43 amino acid residues with five cations, and contains three intramolecular disulfide bonds and a typical cysteine-stabilized αß motif in defensins. Phylogenetic analysis showed that CcDef2 belongs to the insect defensin family. Analysis of gene expression patterns showed that CcDef2 was expressed throughout developmental stages of C. chinensis with high levels at the nymphal stage and in adult tissues tested with the highest level in the fat body. In addition, the CcDef2 expression was significantly upregulated in adults infected by bacteria. After expressed in Escherichia coli BL21(DE3) and renatured, the recombinant CcDef2 showed a significant antibacterial effect on three kinds of Gram-positive bacteria. These results indicate that CcDef2 is an excellent antibacterial peptide and a highly effective immune effector in the innate immunity of C. chinensis. This study provides a foundation for further understanding the function of CcDef2 and developing new antimicrobial drugs.

Glucosamine-6-phosphate N-acetyltransferase gene silencing by parental RNA interference in rice leaf folder, Cnaphalocrocis medinalis (Lepidoptera: Pyralidae).

Parental RNAi (pRNAi) is a response of RNA interference in which treated insect pests progenies showed a gene silencing phenotypes. pRNAi of CmGNA gene has been studied in Cnaphalocrocis medinalis via injection. Our results showed significant reduction in ovulation per female that was 26% and 35.26% in G1 and G2 generations, respectively. Significant reduction of hatched eggs per female were observed 23.53% and 45.26% as compared to control in G1-G2 generations, respectively. We also observed the significant variation in the sex ratio between female (40% and 53%) in G1-G2 generations, and in male (65%) in G1 generation as compared to control. Our results also demonstrated the significant larval mortality (63% and 55%) and pupal mortality (55% and 41%), and significant reduction of mRNA expression level in G1 and G2 generations. Our findings have confirmed that effectiveness of pRNAi induced silencing on the CmGNA target gene in G1-G2 generations of C. medinalis. These results suggested the potential role of pRNAi in insect pest resistance management strategies.

The Genetic Association of Polycystic Ovary Syndrome and the Risk of Endometrial Cancer: A Mendelian Randomization Study.

The association between polycystic ovary syndrome (PCOS) and endometrial cancer remains unclear. We aimed to investigate the causal association between genetically predicted PCOS and endometrial cancer risk in two ethnic groups through a two-sample Mendelian randomization (MR) approach. Our study includes 13 single nucleotide polymorphisms (SNPs) as instrumental variables (IVs) for PCOS in Europeans, and another 13 SNPs are used as IVs for PCOS in Asians. Outcome data were obtained from the largest published meta-GWAS of European ancestry to date, as well as from the BioBank Japan Project of Asian ancestry. Our study demonstrates that genetically predicted PCOS is not causally associated with the risk of overall endometrial cancer in either Europeans or Asians (odds ratio (OR) = 0.93, 95% confidence interval (CI) = 0.85-1.01, p = 0.09 and OR = 0.98, 95% CI 0.84-1.13, p = 0.75, respectively). Subgroup analyses according to histotype further illustrate that PCOS might not be associated with the risk of either endometrioid endometrial cancer or non-endometrioid endometrial cancer in European ancestry. No pleiotropy is found in our study, and a sensitivity analysis shows similar results. Our results indicate that genetically predicted PCOS might not be associated with the risk of endometrial cancer.

The Association Between Genetically Predicted Systemic Inflammatory Regulators and Polycystic Ovary Syndrome: A Mendelian Randomization Study.

Polycystic ovary syndrome (PCOS) is one of the most common endocrine and metabolic diseases among women of reproductive age. Inflammation may be involved in the pathogenesis of PCOS, but its exact relationship with PCOS remains unclear. Herein, we investigate the causal association between systemic inflammatory regulators and PCOS risk through a two-sample Mendelian randomization (MR) approach based on the latest and largest genome-wide association study (GWAS) of 41 systemic inflammatory regulators in 8293 Finnish participants and a GWAS meta-analysis consisting of 10,074 PCOS cases and 103,164 controls of European ancestry. Our results suggest that higher levels of IL-17 and SDF1a, as well as lower levels of SCGFb and IL-4, are associated with an increased risk of PCOS (OR = 1.794, 95% CI = 1.150 - 2.801, P = 0.010; OR = 1.563, 95% CI = 1.055 - 2.315, P = 0.026; OR = 0.838, 95% CI = 0.712 - 0.986, P = 0.034; and OR = 0.637, 95% CI = 0.413 - 0.983, P = 0.042, respectively). In addition, genetically predicted PCOS is related to increased levels of IL-2 and VEGF (OR = 1.257, 95% CI = 1.022 - 1.546, P = 0.030 and OR = 1.112, 95% CI = 1.006 - 1.229, P = 0.038, respectively). Our results indicate the essential role of cytokines in the pathogenesis of PCOS. Further studies are warranted to assess the possibility of these biomarkers as targets for PCOS prevention and treatment.

Effects of Metformin on Reproductive, Endocrine, and Metabolic Characteristics of Female Offspring in a Rat Model of Letrozole-Induced Polycystic Ovarian Syndrome With Insulin Resistance.

The beneficial effects of metformin, especially its capacity to ameliorate insulin resistance (IR) in polycystic ovary syndrome (PCOS), explains why it is widely prescribed. However, its effect on the offspring of patients with PCOS remains uncertain. This study investigated the impact of metformin treatment on the first- and second-generation female offspring born to letrozole-induced PCOS-IR rats. Forty-five female Wistar rats were implanted with continuous-release letrozole pellets or placebo and treated with metformin or vehicle control. Rats exposed to letrozole showed PCOS-like reproductive, endocrine, and metabolic phenotypes in contrast to the controls. Metformin significantly decreased the risk of body weight gain and increased INSR expression in F1 female offspring in PCOS-IR rats, contributing to the improvement in obesity, hyperinsulinemia, and IR. Decreased FSHR expression and increased LHCGR expression were observed in F1 female rats of the PCOS-IR and PCOS-IR+Metformin groups, suggesting that FSHR and LHCGR dysfunction might promote the development of PCOS. Nevertheless, we found no significant differences in INSR, FSHR, and LHCGR expression or other PCOS phenotypes in F2 female offspring of PCOS-IR rats. These findings indicated widespread reproductive, endocrine, and metabolic changes in the PCOS-IR rat model, but the PCOS phenotypes could not be stably inherited by the next generations. Metformin might have contributed to the improvement in obesity, hyperinsulinemia, and IR in F1 female offspring. The results of this study could be used as a theoretical basis in support of using metformin in the treatment of PCOS-IR patients.

Association of Variants in Vascular Endothelial Growth Factor A Gene and VEGFA Serum Levels with the Risk of Primary Ovarian Insufficiency: A Case-Control Study.

OBJECTIVE: The study aimed at investigating the association between the vascular endothelial growth factor A (VEGFA) genetic variants, the VEGFA serum level, and the primary ovarian insufficiency (POI) risk in Chinese Han women. DESIGN: An age-matched case-control study was implemented in the West China Second Hospital of Sichuan University. Participants/Materials, Setting, Methods: Blood samples and clinical information were collected from 240 patients with POI and 261 healthy controls between December 2012 and December 2018 at the West China Second Hospital of Sichuan University. Mutations of VEGFA gene -2578C/A, -1154G/A, 936C/T, and -634C/G were identified by PCR-RFLP. Moreover, VEGFA serum levels in the 2 groups were measured by the enzyme-linked immunosorbent assay (ELISA). RESULTS: The -1154G>A and 936C>T variants of the VEGFA gene were significantly associated with POI (the adjusted odds ratio [OR] = 2.17 and 95% confidence interval [CI] = 1.07-4.43 for the former; the adjusted OR = 2.74 and 95% CI = 1.18-6.34 for the latter), whereas no significant difference was found in the genotype distribution of -2578C>A and -634C>G variants between patients and controls (p > 0.05). Moreover, the combined -1154G>A and 936C>T genotype was associated with a significantly increased risk of POI (the adjusted OR = 21.98, 95% CI = 2.78-173.78 among subjects carrying 3 or more variants), particularly when patients aged ≥35 years (the adjusted OR = 20.58, and 95% CI = 2.58-164.25). The POI group exhibited an obviously lower VEGFA serum level (45.15 ± 1.25 pg/mL) than the control group. Compared with the control, the expression of VEGFA was significantly decreased in the POI group (279.90 ± 5.71 pg/mL; p < 0.05). Moreover, the serum VEGFA levels are lower in the -1154AA genotype than those of AG/GG genotypes. LIMITATIONS: The main limitation is that all participants enrolled in this study were Chinese. As genotype and allelotype frequencies tend to differ between ethnic populations, extrapolation of the results to other ethnic groups should be cautiously considered. CONCLUSIONS: Our study indicates an association between the VEGFA -1154G/A, 936C/T variants, and susceptibility to POI in Chinese Han women. Reduced levels of VEGFA may be a potential mechanism for the de-velopment of POI.

Swainsonine producing performance of Alternaria oxytropis was improved by heavy-ion mutagenesis technology.

Swainsonine, an indolizidine alkaloid, is a promising anti-tumorigenic compound. Biological production of swainsonine was prospective, but the low swainsonine yield of wild type Alternaria oxytropis limited its production on a large scale. In present work, a stable A. oxytropis mutant UO1 with swanisonine yield of 14.84% higher than the wild-type strain was successfully obtained after heavy-ion irradiation. The A. oxytropis mutant UO1 and original wild-type strain were futher evaluated for SW concentrations under different factors. Results showed that the optimum culture temperature was 25°C. The optimum initial medium pH was 6.5 and the optimum inoculum size was 2 mL per 200 mL. Addition of the biosynthetic precursor L-pipecolic acids and L-lysine appropriately could increase the SW synthesis. These findings provided a theoretical basis and scientific data for the industrial production of swainsonine.

Identification and Functional Analysis of a Lysozyme Gene from Coridius chinensis (Hemiptera: Dinidoridae).

Coridius chinensis is a valuable medicinal insect resource in China. Previous studies have indicated that the antibacterial and anticancer effects of the C. chinensis extract mainly come from the active polypeptides. Lysozyme is an effective immune effector in insect innate immunity and usually has excellent bactericidal effects. There are two kinds of lysozymes in insects, c-type and i-type, which play an important role in innate immunity and intestinal digestion. Studying lysozyme in C. chinensis will be helpful to further explore the evolutionary relationship and functional differences among lysozymes of various species and to determine whether they have biological activity and medicinal value. In this study, a lysozyme CcLys2 was identified from C. chinensis. CcLys2 contains 223 amino acid residues, and possesses a typical domain of the c-type lysozyme and a putative catalytic site formed by two conserved residues Glu32 and Asp50. Phylogenetic analysis showed that CcLys2 belongs to the H-branch of the c-type lysozyme. The analysis of spatiotemporal expression patterns indicated that CcLys2 was mainly expressed in the fat body of C. chinensis adults and was highly expressed in the second- and fifth-instar nymphs. In addition, CcLys2 was significantly up-regulated after injecting and feeding bacteria. In the bacterial inhibition assay, it was found that CcLys2 had antibacterial activity against Gram-positive bacteria at a low pH. These results indicate that CcLys2 has muramidase activity, involves in the innate immunity of C. chinensis, and is also closely related to the bacterial immune defense or digestive function of the intestine.

Cloning, Characterization, and RNA Interference Effect of the UDP-N-Acetylglucosamine Pyrophosphorylase Gene in Cnaphalocrocis medinalis.

The rice leaf folder, Cnaphalocrocis medinalis is a major pest of rice and is difficult to control. UDP-N-acetylglucosamine pyrophosphorylase (UAP) is a key enzyme in the chitin synthesis pathway in insects. In this study, the UAP gene from C. medinalis (CmUAP) was cloned and characterized. The cDNA of CmUAP is 1788 bp in length, containing an open reading frame of 1464 nucleotides that encodes 487 amino acids. Homology and phylogenetic analyses of the predicted protein indicated that CmUAP shared 91.79%, 87.89%, and 82.75% identities with UAPs of Glyphodes pyloalis, Ostrinia furnacalis, and Heortia vitessoides, respectively. Expression pattern analyses by droplet digital PCR demonstrated that CmUAP was expressed at all developmental stages and in 12 tissues of C. medinalis adults. Silencing of CmUAP by injection of double-stranded RNA specific to CmUAP caused death, slow growth, reduced feeding and excretion, and weight loss in C. medinalis larvae; meanwhile, severe developmental disorders were observed. The findings suggest that CmUAP is essential for the growth and development of C. medinalis, and that targeting the CmUAP gene through RNAi technology can be used for biological control of this insect.