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Phortica okadai, a polyphagous pest, serves as a vector for Thelazia callipaeda in China. Currently, there are no effective control strategies for this vector. Agricultural pest control may cause P. okadai to become a threat due to the development of pesticide resistance. Cytochrome P450s (CYP450) plays a significant role in detoxifying xenobiotics in insects. In this study, we performed RNA sequencing of P. okadai exposed to ß-cypermethrin for 0 and 1 h and then gene cloning of the five up-regulated CYP450 genes. Three CYP450 genes were successfully cloned, and their expression patterns in different developmental stages and in different tissues were analyzed by RT-qPCR. Pocyp4d2 was observed to have the highest expression in the midgut (fold change 2.82 for Pocyp4d2, 2.62 for Pocyp49a1, and 1.77 for Pocyp28d2). Functional analysis was carried out according to overexpression in S2 cells from the pfastbac1 vector and RNAi with siRNA. The results of the CCK8 assay indicated that the overexpression of the recombinant protein PoCYP4D2 suppressed the decrease in S2 cell viability due to ß-cypermethrin. The expression levels of PoCYP4D2 decreased significantly, and the mortality rates increased from 6.25% to 15.0% at 3 h and from 15.0% to 27.5% at 6 h after Pocyp4d2-siRNA injection. These results suggest that Pocyp4d2 may be an essential key gene in the metabolism of ß-cypermethrin in P. okadai. This study constitutes a foundation to explore further the functions of P. okadai CYP450 genes in insecticide metabolism.

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Shale brittleness is a key index that indicates the shale fracability, provides a basis for selecting wells and intervals to be fractured, and guarantees the good fracturing effect. The available models are not accurate in evaluating the shale brittleness when considering the confining pressure, and it is necessary to establish a new shale brittleness model under the geo-stress. In this study, the variation of elastic energy, fracture energy, and residual elastic energy in the whole process of rock compression and failure is analyzed based on the stress-strain curve in the experiments, and a shale brittleness index reflecting the energy evolution characteristics during rock failure under different confining pressures is established; a method of directly evaluating the shale brittleness with logging data by combining the rock mechanic experiment results with logging interpretation results is proposed. The calculation results show that the brittleness decreases as the confining pressure increases. When the confining pressure of the Kong-2 member shale of the Guandong block is less than 25 MPa, the brittleness index decreases significantly as the confining pressure increases, and when the confining pressure is greater than 25 MPa, the brittleness index decreases slightly. It is shown that the shale brittleness index is more sensitive to the confining pressure within a certain range and less sensitive to the confining pressure above a certain value.

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BACKGROUND: Harvest index (HI) in rice is defined as the ratio of grain yield (GY) to biomass (BM). Although it has been demonstrated that HI is significantly related to yield and is considered as one of the most important traits in high-yielding rice breeding, HI-based high-yielding rice breeding is difficult due to its polygenic nature and insufficient knowledge on the genetic basis of HI. Therefore, searching for rice varieties with high HI and mapping genes associated with high HI can facilitate marker-assisted breeding for high HI in rice. RESULTS: Yuexiangzhan, a popular indica cultivar with good reputation of high HI was crossed with Shengbasimiao, an indica cultivar with lower HI to develop a recombinant inbred line population, and QTL mapping for HI and its component traits was conducted. In total, five QTLs for HI, three QTLs for GY, and six QTLs for BM were detected in two-year experiments. Among the three GY QTLs, one co-located with the HI QTL on chromosome 8, while the other two co-located with the two tightly-linked BM QTLs on chromosome 3. The co-located QTLs in each of the chromosomal regions produced additive effects in the same direction. Particularly, the HI QTL on chromosome 8, qHI-8, could be detected across two years and explained 42.8% and 44.5% of the phenotypic variation, respectively. The existence of qHI-8 was confirmed by the evaluation of the near isogenic lines derived from a residual heterozygous line, and this QTL was delimitated to a 1070 kb interval by substitution mapping. CONCLUSION: In the present study, the detected GY QTLs overlapped with both HI QTL and BM QTL, suggesting a positive relationship between GY and HI or BM, respectively. With an understanding of the genetic basis for grain yield, harvest index and biomass, it is possible to achieve higher yield through enhancing HI and BM by pyramiding the favorable alleles for the two traits via marker-assisted selection (MAS). As qHI-8 has a large phenotypic effect on HI and expresses stably in different environments, it provides a promising target for further genetic characterization of HI and MAS of high HI in rice breeding.

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AIM: To investigate the anti-obesity and antibacterial effects of Ligustrum robustum (L. robustum) in vivo and in vitro and its possible mechanisms. METHODS: The effects of L. robustum aqueous extract (LR) on various gut bacteria in vitro were evaluated. The effects of LR on high-fat diet-fed (HFD) rats in vivo were also assessed. Culture methods, quantitative polymerase chain reaction, and terminal-restriction fragment length polymorphism were used to analyze the effects of LR on gut bacteria. Biochemical tests were also performed to detect the changes in obesity-related indicators after LR treatment. RESULTS: LR treatment lowered adipose weight and decreased Lee's index, blood glucose, total cholesterol, and lipid in the tested groups relative to control (P < 0.05). To determine the reasons for these changes, we assessed the potential bacteriostatic and bactericidal effects of LR on specific bacterial species in vitro. LR affected the richness, diversity, and evenness of gut bacteria, increased fecal Lactobacillus, and decreased Enterococci in HFD rats (P < 0.05). CONCLUSION: L. robustum may be a safe and effective food for weight loss and obesity control, and the effects of L. robustum might be mediated by the regulation of gut bacteria.

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AIM: To investigate the differences in cultivable gut bacteria and peroxisome proliferator-activated receptor γ2 (PPAR-γ2) gene Pro12Ala variation in obese and normal-weight Chinese people. METHODS: Using culture methods, the amounts of Escherichia coli, Enterococci, Bacteroides, Lactobacilli, Bifidobacteria and Clostridium perfringens (C. perfringens) in the feces of 52 obese participants [body mass index (BMI): ≥ 28 kg/m(2)] and 52 participants of normal-weight (BMI: 18.5-24 kg/m(2)) were obtained. Study participants completed comprehensive questionnaires and underwent clinical laboratory tests. The polymerase chain reaction-restriction fragment length polymorphism (PCR-PFLP) assay was used to analyze PPAR-γ2 gene Pro12Ala variation. RESULTS: The obese group exhibited a lower amount of C. perfringens (6.54 ± 0.65 vs 6.94 ± 0.57, P = 0.001) and Bacteroides (9.81 ± 0.58 vs 10.06 ± 0.39, P = 0.012) than their normal-weight counterparts. No major differences were observed in Pro12Ala genotype distribution between the two groups; however, obese individuals with a Pro/Ala genotype had a significantly lower level of Bacteroides (9.45 ± 0.62 vs 9.93 ± 0.51, P = 0.027) than those with a Pro/Pro genotype. In addition, the obese group demonstrated a higher stool frequency (U = 975, P < 0.001) and a looser stool (U = 1062, P = 0.015) than the normal-weight group. CONCLUSION: Our results indicated interactions among cultivable gut flora, host genetic factors and obese phenotype and this might be helpful for obesity prevention.

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OBJECTIVE: To study on the polymorphism of UCP2 gene in Chengdu simple obesity and normal-weight people and to initially investigate the relationship between UCP2 Ala55Val variation and gut bacteria. METHODS: PCR-PFLP was applied to determine the genotypes of Ala55Val variant in the UCP2 gene of 86 Chengdu people (the simple obesity group, 43 subjects; the normal-weight group, 43 subjects). And six kinds of gut bacteria among different genotypes in different groups were analyzed. RESULTS: Both the simple obesity and the normal-weight group had the Ala55Val variants of Ala/Ala, Val/Val and Ala/Val in the UCP2 gene, and the Ala55Val genotype distributions between the two groups was significantly different (chi2=11.97, P< 0.05). The allelic mutation frequency in the simple obesity group was higher than that of the normal-weight group (chi2=10.06, P<0.05). However, no significant difference was observed in the population of six gut bacteria among different genotypes in different groups (P>0.05). CONCLUSION: The UCP2 gene mutation might be a risk factor of obesity in Chengdu area. However, this gene mutation may not be an impact factor on the alternation of gut bacteria.

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OBJECTIVE: To identify the relationship between amino acid mutations in Neisseria gonorrhoeae isolates and their antibiotic resistance. METHODS: PI gene fragments of Neisseria gonorrhoeae from 17 clinical isolates were obtained with PCR amplification. They were cloned into the PCR cloning vector pBS-T to form pBS-T-PI and sequenced. The sequences of PI genes were analyzed. At the same time, minimum inhibitory concentration (MIC) of penicillin and tetracycline to these 17 isolates were measured and contrasted with the corresponding PI sequence. RESULTS: The recombinants of PI gene from 17 clinical isolates of Neisseria gonorrhoeae were successfully constructed and sequenced. They were divided into PIA and PIB subtypes according to the results from blastn software by comparing the sequences with the GenBank. Mutations were found at the sites of 120 and 121. There were only some of the sequences having an aspartic acid (D) mutation on 120 and 121 sites, which was not the same as reported. On the other hand,there were two PI sequences,5-9 and 6-1, whose mutations on No. 120 were lysine, similar to those documented. CONCLUSION: Some relationship between PI amino acids mutations at sites 120 and 121 in Neisseria gonorrhoeae isolates from Chengdu, China and their resistance to penicillin and tetracycline were found. However,further studies need to be done in the future to confirm this hypothesis.

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