Highly stabilized and efficient thermoelectric copper selenide.

The liquid-like feature of thermoelectric superionic conductors is a double-edged sword: the long-range migration of ions hinders the phonon transport, but their directional segregation greatly impairs the service stability. We report the synergetic enhancement in figure of merit (ZT) and stability in Cu1.99Se-based superionic conductors enabled by ion confinement effects. Guided by density functional theory and nudged elastic band simulations, we elevated the activation energy to restrict ion migrations through a cation-anion co-doping strategy. We reduced the carrier concentration without sacrificing the low thermal conductivity, obtaining a ZT of ∼3.0 at 1,050 K. Notably, the fabricated device module maintained a high conversion efficiency of up to ∼13.4% for a temperature difference of 518 K without obvious degradation after 120 cycles. Our work could be generalized to develop electrically and thermally robust functional materials with ionic migration characteristics.

Can transrectal ultrasonography distinguish anorectal malignant melanoma from low rectal adenocarcinoma? A retrospective paired study for ten years.

BACKGROUND: Anorectal malignant melanoma (ARMM) and low rectal adenocarcinoma (LRAC) have some similarities in clinical behaviors, histopathological characteristics and ultrasonographic findings, diagnostic errors are common. By comparing the transrectally ultrasonographic features between the two tumors, we propose to provide more possibilities in differentiating them. METHODS: The data of 9 ARMMs and 27 age- and gender-matched LRACs (the lower margin below the peritoneal reflection) in West China Hospital Sichuan University between April 2008 and July 2019 were retrospectively reviewed. The ultrasonic features between the two groups were compared. RESULTS: Transrectal ultrasonography (TRUS) showed that the length of ARMM was shorter than that of LRAC (28.22 ± 12.29 mm vs. 40.22 ± 15.16 mm), and ARMM had a lower position than that of LRAC (the distance to anal verge was 50.78 ± 11.70 vs. 63.81 ± 18.73 mm). Unlike LRAC, the majority of ARMM in our study was confined to the intestinal mucosa/submucosa (66.67/25.93%) (P < 0.05). CONCLUSIONS: Based on the data of our study, several ultrasonographic findings (length, invasion depth, and position) of ARMM were significantly different from LRAC. Accordingly, more attention should be paid to masses at anorectal junction with lower position, shorter length, and shallower infiltration depth. Instead of the most common tumor, LRAC, ARMM should be taken into account to avoid a misdiagnosis, which will result in a poorer prognosis.

Identification of Mahonia Species as Alternate Hosts for Puccinia striiformis f. sp. tritici and Determination of Existence of Sexual Propagation of the Rust Pathogen on Mahonia Under Natural Conditions in China.

Many Berberis species have been identified as alternate hosts for Puccinia striiformis f. sp. tritici. Importantly, susceptible Berberis species are determined to play an important role in the occurrence of sexual reproduction, generation of new races of the rust pathogen. However, little is known about Mahonia serving as alternate hosts for P. striiformis f. sp. tritici and their role to commence sexual reproduction of the rust fungus under natural conditions. Herein, three Mahonia species or subspecies, Mahonia fortunei, M. eurybracteata subsp. ganpinensis, and M. sheridaniana, were identified as alternate hosts for P. striiformis f. sp. tritici, and seven Mahonia species were highly resistant to the rust pathogen. We recovered seven samples of P. striiformis f. sp. tritici from naturally rusted Mahonia cardiophylla plants. Totally, 54 single uredinium (SU) isolates, derived from the seven samples, generated 20 different race types, including one known race type, and 19 new race types. SNP markers analysis showed that all SU isolates displayed high phenotype diversity (H = 0.32) with a high Shannon's information index (I = 0.49). Analysis of linkage disequilibrium indicated an insignificant rbarD value (rbarD = 0.003, P < 0.1). As a result, all SU isolates are sexually produced, suggesting that P. striiformis f. sp. tritici parasitizes susceptible Mahonia to complete sexual reproduction under natural conditions. The role of Mahonia in occurrence of wheat stripe rust are needed to study for management of the disease.

Distinct Transcriptomic Reprogramming in the Wheat Stripe Rust Fungus During the Initial Infection of Wheat and Barberry.

Puccinia striiformis f. sp. tritici is the causal agent of wheat stripe rust that causes severe yield losses all over the world. As a macrocyclic heteroecious rust fungus, it is able to infect two unrelated host plants, wheat and barberry. Its urediniospores infect wheat and cause disease epidemic, while its basidiospores parasitize barberry to fulfill the sexual reproduction. This complex life cycle poses interesting questions on the different mechanisms of pathogenesis underlying the infection of the two different hosts. In the present study, transcriptomes of P. striiformis f. sp. tritici during the initial infection of wheat and barberry leaves were qualitatively and quantitatively compared. As a result, 142 wheat-specifically expressed genes (WEGs) were identified, which was far less than the 2,677 barberry-specifically expressed genes (BEGs). A larger proportion of evolutionarily conserved genes were observed in BEGs than that in WEGs, implying a longer history of the interaction between P. striiformis f. sp. tritici and barberry. Additionally, P. striiformis f. sp. tritici differentially expressed genes (DEGs) between wheat at 1 and 2 days postinoculation (dpi) and barberry at 3 and 4 dpi were identified by quantitative analysis. Gene Ontology analysis of these DEGs and expression patterns of P. striiformis f. sp. tritici pathogenic genes, including those encoding candidate secreted effectors, cell wall-degrading enzymes, and nutrient transporters, demonstrated that urediniospores and basidiospores exploited distinct strategies to overcome host defense systems. These results represent the first analysis of the P. striiformis f. sp. tritici transcriptome in barberry and contribute to a better understanding of the evolutionary processes and strategies of different types of rust spores during the infection process on different hosts.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Neoadjuvant Radiotherapy Versus Surgery Alone for Stage II/III Mid-low Rectal Cancer With or Without High-risk Factors: A Prospective Multicenter Stratified Randomized Trial.

OBJECTIVE: The aim of this study was to compare stage II/III rectal cancers with or without high-risk factors, and evaluate the effect of neoadjuvant radiotherapy (NRT) in these 2 cohorts. BACKGROUND: NRT is often used in stage II/III rectal cancers to improve local control, while not affecting overall survival. However, good-quality surgery without NRT may also achieve good local control in selected patients. METHODS: According to risk-stratification criteria and clinical staging, consecutive eligible participants of stage II/III rectal cancer were preoperatively classified into patients with (high-risk) or without (low-risk) high-risk factors. Both groups were respectively randomized to receive either short-course radiotherapy (SCRT) + total mesorectal excision (TME) or TME alone, forming the following 4 groups: high-risk patients with (HiR) or without (HiS) radiation, and low-risk patients with (LoR) or without (LoS) radiation. The primary endpoint was local recurrence. The secondary endpoints included overall survival, disease-free survival, distant recurrence, quality of surgery, and safety (NCT01437514). RESULTS: In total, 401 patients were analyzed. With a median 54 months' follow-up, low-risk patients obtained better 3-year cumulative incidence of local recurrence (2.2% vs 11.0%, P = 0.006), overall survival rate (86.9%vs 76.5%, P = 0.002), disease-free survival rate (87.0% vs 67.9%, P < 0.001), and cumulative incidence of distant recurrence (12.5% vs 29.4%, P < 0.001) than high-risk patients. With regard to 3-year cumulative incidence of local recurrence, no differences were observed between the LoR and LoS groups (1.2% vs 3.0%, P = 0.983) or the HiR and HiS groups (12.9% vs 8.9%, P = 0.483). CONCLUSIONS AND RELEVANCE: Stratification of stage II/III rectal cancers according to risk factors to more precise subclassifications may result in noteworthy differences in survivals and local pelvic control. An extremely low cumulative incidence of local recurrence and survivals in low-risk patients can be achieved with upfront good quality of surgery alone. This trial, owing to the insufficient power, could not prove the noninferiority of surgery alone, but suggest a discriminative use of NRT according to clinical risk stratification in stage II/III rectal cancer.

Repression of let-7b-5p prevents the development of multifidus muscle dysfunction by promoting vitamin D accumulation via upregulation of electron transfer flavoprotein alpha subunit in a rat model of multifidus muscle injury.

Multifidus muscle dysfunction is associated with the multifidus muscle injury (MMI), which ultimately result in the low-back pain. Increasing evidence shows that microRNAs (miRs) may be involved in multifidus muscle dysfunction. In this study, we tested the hypothesis that downregulation of let-7b-5p may inhibit the multifidus muscle dysfunction development and progression. The target prediction program and luciferase activity determination confirmed electron transfer flavoprotein alpha subunit (ETFA) as a direct target gene of let-7b-5p. To study the mechanisms and functions of let-7b-5p in relation to ETFA in MMI progression, we prepared rats with experimental MMI, and a lentivirus-based packaging system was designed to upregulate expressions of let-7b-5p, and downregulate the expression of ETFA. ETFA was identified as a target gene of let-7b-5p. Older age, a longer duration of pain, and higher visual analog scale and Oswestry disability index scores for the patients with chronic low-back pain were linked to a more severe degree of degenerative muscle atrophy and fatty infiltration. Increased expression of let-7b-5p and decreased expression of ETFA and vitamin D receptor (VDR) were positively correlated with multifidus muscle dysfunction. Downregulated let-7b-5p could inhibit infiltration of collagen fibers, reverse the ultrastructural changes of multifidus muscle, and induce the VDR expression, thereby repair the MMI. The results provided a potential basis for let-7b-5p that could support targeted intervention in multifidus muscle dysfunction. Collectively, this study confirmed that downregulation of let-7b-5p has a potential inhibitory effect on the development of the function of the musculus myocytes by upregulating ETFA.

TaAMT2;3a, a wheat AMT2-type ammonium transporter, facilitates the infection of stripe rust fungus on wheat.

BACKGROUND: Ammonium transporters (AMTs), a family of proteins transporting ammonium salt and its analogues, have been studied in many aspects. Although numerous studies have found that ammonium affects the interaction between plants and pathogens, the role of AMTs remains largely unknown, especially that of the AMT2-type AMTs. RESULTS: In the present study, we found that the concentration of ammonium in wheat leaves decreased after infection with Puccinia striiformis f. sp. tritici (Pst), the causal agent of stripe rust. Then, an AMT2-type ammonium transporter gene induced by Pst was identified and designated as TaAMT2;3a. Transient expression assays indicated that TaAMT2;3a was located to the cell and nuclear membranes. TaAMT2;3a successfully complemented the function of a yeast mutant defective in NH4+ transport, indicating its ammonium transport capacity. Function of TaAMT2;3a in wheat-Pst interaction was further analyzed by barley stripe mosaic virus (BSMV)-induced gene silencing. Pst growth was significantly retarded in TaAMT2;3a-knockdown plants, in which ammonium in leaves were shown to be induced at the early stage of infection. Histological observation showed that the hyphal length, the number of hyphal branches and haustorial mother cells decreased in the TaAMT2;3a knockdown plants, leading to the impeded growth of rust pathogens. CONCLUSIONS: The results clearly indicate that the induction of AMT2-type ammonium transporter gene TaAMT2;3a may facilitates the nitrogen uptake from wheat leaves by Pst, thereby contribute to the infection of rust fungi.

Complete genome sequence of a novel mitovirus from the wheat stripe rust fungus Puccinia striiformis.

The complete genome of a novel mycovirus, Puccinia striiformis mitovirus 1 (PsMV1), derived from the wheat stripe rust fungus Puccinia striiformis strain SCSN-10, was sequenced and analyzed. The full-length cDNA sequence is 2496 bp in length with a predicted AU content of 57.65% in the genomic RNA. Sequence analysis indicated that a single large open reading frame (ORF) is present on the positive strand when the fungal mitochondrial genetic code is used. The single ORF encodes a putative RNA-dependent RNA polymerase of 743 amino acids with a molecular mass of 84.9 kDa that shares the closest similarity with the corresponding proteins of Cronartium ribicola mitovirus 5 and Helicobasidium mompa mitovirus 1-18 (34% and 35% aa sequence identity, respectively). Phylogenetic analysis further indicated that PsMV1 is a new member of the genus Mitovirus within the family Narnaviridae. This is the first report of the full-length nucleotide sequence of a novel mitovirus, PsMV1, from the causal agent of wheat stripe rust.

Serine protease PRSS55 is crucial for male mouse fertility via affecting sperm migration and sperm-egg binding.

Testis-specific PRSS55 is a highly conserved chymotrypsin-like serine protease among mammalian species. So far, the physiological function of PRSS55 remains unknown. Here, we show that PRSS55 is a GPI-anchored membrane protein, specifically expressed in adult mouse testis and mainly observed in the luminal side of seminiferous tubules and sperm acrosome. Mice deficient for Prss55 develop male infertile with normal reproduction-related parameters observed. Interestingly, in vivo fertilization rate of Prss55-/- males is dramatically decreased, possibly due to incapable migration of Prss55-/- sperm from uterus into oviduct. However, in vitro fertilization rate has no difference between two genotypes although Prss55-/- sperm presents defective recognition/binding to zona-intact or zona-free oocytes. Further study reveals that mature ADAM3 is almost undetectable in Prss55-/- sperm, while precursor ADAM3 remains unchanged in the testis. However, it is shown that ADAM3 has no interaction with PRSS55 by immunoprecipitation with anti-PRSS55 antibody. The expression levels of several proteins known to be related to the observed phenotypes remain comparable between wt and Prss55-/- mice. Moreover, we found that Prss55 deficiency has no effect on PRSS37 or vice versa albeit two mutant males share almost the same phenotypes. Microarray analysis reveals a total of 72 differentially expressed genes in Prss55-/- testis, most of which are associated with cellular membrane and organelle organization, protein transport and complex assembly, and response to stimulus and signaling. In conclusion, we have demonstrated that PRSS55 plays vital roles in regulating male fertility of mice, including in vivo sperm migration and in vitro sperm-egg interaction, possibly by affecting the maturation of ADAM3 in sperm and the expression of multiple genes in testis.

[Grading method of inhomogeneity of contrast-enhanced ultrasound for rectal tumors based on gray level co-occurrence matrix].

Transrectal contrast-enhanced ultrasound (CEUS) is an important examination for rectal tumors. The inhomogeneity of the CEUS images has important clinical significance. However, there is no objective method to evaluate this index. In this study, a method based on gray-level co-occurrence matrix (GLCM) is proposed to extract texture features of images and grade these images according the inhomogeneity. Specific processes include compressing the gray level of the image, calculating the texture statistics of gray level co-occurrence matrix, combining feature selection and principal component analysis (PCA) for dimensionality reduction, and training and validating quadratic discriminant analysis (QDA). After ten cross-validation, the overall accuracy rate of machine classification was 87.01%, and the accuracy of each level was as follows: Grade Ⅰ 52.94%, Grade Ⅱ 96.48% and Grade Ⅲ 92.35% respectively. The proposed method has high accuracy in judging grade Ⅱ and Ⅲ images, which can help to identify the grade of inhomogeneity of contrast-enhanced ultrasound images of rectal tumors, and may be used to assist clinical doctors in judging the grade of inhomogeneity of contrast-enhanced ultrasound of rectal tumors.

LncRNA-DANCR contributes to lung adenocarcinoma progression by sponging miR-496 to modulate mTOR expression.

Long non-coding RNAs (lncRNAs) have emerged as new and important regulators of pathological processes including tumour development. In this study, we demonstrated that differentiation antagonizing non-protein coding RNA (DANCR) was up-regulated in lung adenocarcinoma (ADC) and that the knockdown of DANCR inhibited tumour cell proliferation, migration and invasion and restored cell apoptosis rescued; cotransfection with a miR-496 inhibitor reversed these effects. Luciferase reporter assays showed that miR-496 directly modulated DANCR; additionally, we used RNA-binding protein immunoprecipitation (RIP) and RNA pull-down assays to further confirm that the suppression of DANCR by miR-496 was RISC-dependent. Our study also indicated that mTOR was a target of miR-496 and that DANCR could modulate the expression levels of mTOR by working as a competing endogenous RNA (ceRNA). Furthermore, the knockdown of DANCR reduced tumour volumes in vivo compared with those of the control group. In conclusion, this study showed that DANCR might be an oncogenic lncRNA that regulates mTOR expression through directly binding to miR-496. DANCR may be regarded as a biomarker or therapeutic target for ADC.

A Miniature Cell Pattern Formation of Ovarian Cancer Cell Lines on Self-Assembling Peptide Nanofiber-Coated Coverslip and In Vitro Chemosensitivity Assay.

BACKGROUND: Despite of intensive efforts, the tumor progression of ovarian cancer has not yet been fully understood. Various studies suggest that an effective experimental model system In Vitro to mimic microenvironment in vivo and the fabrication of cell pattern formation In Vitro are of great importance for the ovarian cancer research. METHODS: This study cultivates SKOV3, A2780 and A2780/DDP ovarian cancer cell lines in RADA16-I peptide hydrogel to obtain 3D-precultured cancer cells and fabricate a type of miniature cell pattern formation In Vitro on RADA16-I peptide nanofibercoated coverslip by in situ AFM analysis and chemosensitivity assay in vitro. RESULTS: SKOV3, A2780 and A2780/DDP cells were regularly cultivated in RADA16-I peptide hydrogel, respectively, and present defined cellular characteristics, such as small cell colonies, cell clusters and cell aggregates, etc. On coverslip coated with RADA16-I peptide nanofiber, three 3D-precultured cell lines were flat and spread on coverslips and the regular topographic images by AFM were obtained. The chemosensitivity assay of three ovarian cancer cell lines were significantly different in RADA16-I peptide-coated coverslips compared with 2D dish plates. CONCLUSIONS: By 3D cell culture of ovarian cancer cell lines in RADA16-I peptide hydrogel In Vitro, the cell culture model systems was fabricated. The miniature cell pattern formation In Vitro on peptide nanofiber-coated coverslip was particularly useful experiemental model systems to be served as a valuable methodology for studying ovarian cancer biology.

Safety and efficacy of transpupillary silicone oil removal in combination with micro-incision phacoemulsification cataract surgery: comparison with 23-gauge approach.

BACKGROUND: To evaluate safety and efficacy of transpupillary silicone oil removal combined with micro-incision phacoemulsification cataract surgery, and to compare results of transpupillary with 23-gauge three-port vitrectomy approach. METHODS: Consecutive cases that underwent silicone oil removal using either transpupillary or three-port approach in combination with micro-incision phacoemulsification cataract surgery were retrospectively reviewed. The main outcome measures were postoperative detachment rate, silicone oil residuals, best corrected visual acuity (BCVA) and intraocular pressure (IOP). RESULTS: A total of 64 cases were included, 19 in transpupillary and 45 in three-port. Postoperative detachment rate within 3 months in transpupillary versus three-port was 15.8% versus 4.4% (p = 0.14), Silicone oil residuals was 7.4 ± 3.2% versus 7.1 ± 2.8% (transpupillary vs. three-port, p = 0.71). Preoperative versus postoperative BCVA (logMAR) was 1.49 ± 0.61 versus 1.42 ± 0.61 in transpupillary approach (p = 0.28) and 1.53 ± 0.48 versus 1.45 ± 0.57 in three-port approach (p = 0.11). Transpupillary approach resulted in lower IOP at postoperative day 2 (12.2 ± 2.3 mmHg vs. 13.5 ± 2.2 mmHg, p < 0.05), while postoperative follow-up at 1 month revealed no significant difference (p = 0.21). CONCLUSIONS: Transpupillary silicone oil removal combined with micro-incision phacoemulsification cataract surgery is less invasive and can be an alternative in some circumstances.

[The Diagnostic Value of Double Contrast Enhanced Ultrasound in Colorectal Neoplasms].

OBJECTIVES: To determine the value of double contrast enhanced ultrasound (DCEUS) in detecting colorectal neoplasms. METHODS: The conventional abdominal ultrasound and DCEUS (hydrocolonal ultrasound+intravenous contrast-enhanced ultrasonography) were performed in 77 patients with 79 colorectal tumors. The clinical, ultrasonic and pathological data of the patients were reviewed. RESULTS: The conventional abdominal ultrasound detected 32 colorectal tumors (32/79, with a sensitivity of 40.1%), compared with 68 tumors found in DCEUS (68/79, with a sensitivity of 86.1%). The tumors were located accurately in 21.9%(7/32) and 88.2%(60/68) cases for the conventional abdominal ultrasound and DCEUS, respectively ( P<0.05). DCEUS accurately located 94.4%(51/54)cased with colon neoplasm. Two types of enhancing modes were found with colorectal neoplasm: entirely homogeneous enhancing and heterogeneous enhancing perpendicularly from the serosal part to the mucosal part. The enhancing modes were associated with the morphology of neoplasm. Thirty-nine segmented-thickened tumors were found with perpendicularly enhancing from the serosal surface to the mucosal surface, while 29 protruding tumors were found with enhancing from their pedicles or fund. CONCLUSIONS: DCEUS has higher detection sensitivity and location accuracy than conventional ultrasound.

[Quantitative Study on Angiogenesis Features of Human Lung Adenocarcinoma Xenografted into Nude Mouse Model Using Time-intensity Curve Parameters with Contrast Enhanced Ultrasonography].

This research is to explore the perfusion time-intensity curve parameters of a lung adenocarcinoma xenograft into nude mouse model with contrast enhanced ultrasonography(CEUS);and to investigate the angiogenesis features of tumor at different growth time.Twenty one lung adenocarcinoma xenografted nude mice were divided into three groups and inculcated with human lung adenocarcinoa.Time window for examining CEUS were respectively in7-day,14-day and 28-day.The perfusion parameters including rise time(RT),peak intensity(PI),area under the curve(AUC)of lung tumor were obtained on CEUS images by using off-line software Q lab.Immunohistochemically staining for CD34 was used to observe the microvessel density(MVD).The 7-day group had the highest AUC and PI;AUC and PI of 14-day and 28-day group decreased gradually(P<0.05).RT was increased as tumor growth.In tumor with necrosis,AUC and PI of non-necrosis part were also larger than necrosis part(P<0.05).Immunohistochemically staining for CD34 of all tumors reflected that the density of microvessels in necrosis tumor was significantly higher than those without necrosis(7.50±3.44 vs.12.44±5.74,P=0.034).Pearson correlation indicated that PI was positively related with MVD(r=0.668,P=0.008).Lung adenocarcinoma perfusion characteristic can be accessed from time-intensity curve parameters by using noninvasively and non-radiative contrast enhanced ultrasonography.Time-intensity curve parameters including AUC,PI and RT may reflect tumor angiogenesis.

Establishment, characterization, and application of pAcr-SP-NTP-EGFP transgenic mice in visualizing the oviduct-migrating ability of sperm from Prss37-null mice.

Transgenic mouse model with fluorescently labeled sperm has extensive application value. It is an auxiliary tool for investigating the mechanism of fertilization, especially for visualizing the oviduct-migrating ability of sperm in vivo. Here, we produced transgenic mouse lines whose sperm were tagged with enhanced green fluorescent protein (EGFP) according to the previously described method. Polymerase chain reaction analysis of tail-tip genomic DNA identified 13 founders, of which 5 male founders produced offspring to form transgenic lines. We showed that EGFP was testis-specifically expressed, sharing similar expression pattern with endogenous acrosin. It has luminal side restricted distribution in seminiferous tubules and acrosomal aggregation in mature sperm. In addition, interstrain hybridization obtained Prss37(-/-)EGFP(tg/+) males produced sperm with impaired oviduct-migrating ability as visualized under fluorescence microscope, compared with Prss37(+/+)EGFP(tg/+) counterparts. These results indicate that a transgenic mouse model with fluorescently labeled sperm has been successfully established and it is a useful tool for evaluating the oviduct-migrating ability of sperm.

[A quick and efficient method to generate hemophilia B mouse models by the CRISPR/Cas system].

Hemophilia B, or the Christmas disease, is a common human disease caused by coagulation factor Ⅸ (FⅨ) deficiency. It is an X-linked recessive hereditary disease. Here we obtained FⅨ-knockout mouse strains with phenotype of hemophilia B with the CRISPR/Cas system efficiently. We chose the 8th exon as the target locus, and co-injected codon-optimized Cas9 mRNA with sgRNA of FⅨ into C57BL/6 mice zygotes. We obtained 60 mice in total and genotyped them by high resolution melting (HRM) and sequencing. The results showed the mutation rate was 85.0% in total, and 79.5% and 95.2% in males and females, respectively. No off-targets were detected in the similar locus by HRM. We future measured the FⅨ activity of each mice. The FⅨ: C of mutant mice were significantly below the normal level and reduced to 6.82% of wild-type mice. The activity assay demonstrated that all the mutant mice were lack of FⅨ. In summary, we have generated hemophilia B model mice with extreme efficiency, using the RNA-guided Cas9 nuclease gene editing system.

Identification and characterization of ace2-type acetylcholinesterase in insecticide-resistant and -susceptible parasitoid wasp Oomyzus sokolowskii (Hymenoptera: Eulophidae).

A full-length acetylcholinesterase (AChE) cDNA sequence (Os-ace2.s) from insecticide-susceptible (S) parasitoid Oomyzus sokolowskii (Hymenoptera: Eulophidae) and a partial cDNA sequence (Os-ace2.r) from insecticide- resistant (R) O. sokolowskii were identified firstly. Both Os-ace2.s (encoding a protein of 639 amino acid residues) and Os-ace2.r (encoding a protein of 530 amino acid residues) contained the typical conserved motifs, including FGESAGdomains, catalytic triad, acyl pocket, three oxy-anino hole, choline binding site, peripheral anionic site, omega loop and conserved aromatic residues. The multiple alignment and Blast results indicated that Os-ace2.s were ace2 member of AChE gene. There were three replacements of the amino acid residues (Glu 115 Leu, Phe 394 Leu, and Lys 424 Arg) between Os-ace2.s and Os-ace2.r. The ace2 of O. sokolowskii was the AChE gene firstly isolated from hymenopteran parasitoid so far. R O. sokolowskii displayed about 15-20-folds resistance ratios to methamidophos and avermectin. The bimolecular rate constant (k i) value in S O. sokolowskii was 3.8-folds for methamidophos and 12.3 for dichlorvos, respectively higher than those in R O. sokolowskii. The results indicated that the insensitive AChE and replacements of the amino acid residues in Os-ace2 might be involved in the resistance to methamidophos in R O. sokolowskii.

Cloning and characterization of a dynein light chain gene from Puccinia striiformis f. sp. tritici.

Stripe rust is one of the most serious wheat diseases worldwide. The fungus Puccinia striiformis f. sp. tritici (Pst), the causal agent of this disease, is an obligate biotrophic basidiomycete fungus. Numerous studies have shown that dyneins play important roles during fungal growth and propagation. However, knowledge is limited regarding the function of dyneins in Pst. In this study, we cloned the dynein light chain gene PsDLC1 from Pst and characterized its expression. The function of PsDLC1 was determined by heterologous mutant complementation. Expression of PsDLC1 in Aspergillus nidulans partially complemented the defects of the ΔnudG mutant, indicating that PsDLC1 belongs to the dynein light chain LC8 family. In addition, PsDLC1 was identified in Pst using virus-induced gene silencing (VIGS). Knockdown of PsDLC1 produces no significant effect on Pst growth and development, indicating that PsDLC1 is unnecessary for Pst infection of wheat.

Cloning and molecular characterization of a myosin light chain gene from Puccinia striiformis f. sp. tritici.

The fungus Puccinia striiformis f. sp. tritici (Pst), the causal agent of wheat stripe rust, is an obligate biotrophic basidiomycete. Many studies have found that myosins play important roles during fungal growth and propagation. However, there are few reports on the myosins of Pst. In this study, we cloned and obtained the myosin light chain gene PsMLC1 from Pst and characterized its expression. Furthermore, the function of PsMLC1 was identified by mutant complementation. As a result, we found that expression of PsMLC1 in Schizosaccharomyces pombe mostly complemented the defects of the cdc4 mutant, indicating that PsMLC1 belongs to the myosin light chain family member. Expression studies showed that the transcript levels of PsMLC1 little changed before 24 h post inoculation then was suddenly down-regulated during Pst infection of wheat. By using ML-7, we observed that inactivity of PsMLC1 greatly reduced the germination rate of urediniospores. These results suggest that PsMLC1 is essential for the early stages of Pst infection of wheat but unnecessary for the later stages of infection. This work elucidates the function of the myosins in Pst and may provide some theoretical basis for controlling strip rust.