A New Species of Scymnus (Coleoptera, Coccinellidae) from Pakistan with Mitochondrial Genome and Its Phylogenetic Implications.

In this study, a new species of the subgenus Pullus belonging to the Scymnus genus from Pakistan, Scymnus (Pullus) cardi sp. nov., was described and illustrated, with information on its distribution, host plants, and prey. Additionally, the completed mitochondrial genome (mitogenome) of the new species using high-throughput sequencing technology was obtained. The genome contains the typical 37 genes (13 protein-coding genes, two ribosomal RNAs, and 22 transfer RNAs) and a non-coding control region, and is arranged in the same order as that of the putative ancestor of beetles. The AT content of the mitogenome is approximately 85.1%, with AT skew and GC skew of 0.05 and -0.43, respectively. The calculated values of relative synonymous codon usage (RSCU) determine that the codon UUA (L) has the highest frequency. Furthermore, we explored the phylogenetic relationship among 59 representatives of the Coccinellidae using Bayesian inference and maximum likelihood methods, the results of which strongly support the monophyly of Coccinellinae. The phylogenetic results positioned Scymnus (Pullus) cardi in a well-supported clade with Scymnus (Pullus) loewii and Scymnus (Pullus) rubricaudus within the genus Scymnus and the tribe Scymnini. The mitochondrial sequence of S. (P.) cardi will contribute to the mitochondrial genome database and provide helpful information for the identification and phylogeny of Coccinellidae.

CRISPR/dCas9-Mediated Parkin Inhibition Impairs Mitophagy and Aggravates Apoptosis of Rat Nucleus Pulposus Cells Under Oxidative Stress.

OBJECTIVE: The aim of this study is to explore the role of Parkin in intervertebral disk degeneration (IDD) and its mitophagy regulation mechanism. STUDY DESIGN AND METHODS: Rat nucleus pulposus (NP) cells were stimulated with hydrogen peroxide (H2O2) to a mimic pathological condition. Apoptosis and mitophagy were assessed by Western blot, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, and immunofluorescence staining. The CRISPR-dCas9-KRAB system was used to silence the expression of Parkin. RESULT: In this study, we found that Parkin was downregulated in rat NP cells under oxidative stress. In addition, treatment with H2O2 resulted in mitochondrial dysfunction, autophagy inhibition, and a significant increase in the rate of apoptosis of NP cells. Meanwhile, mitophagy inhibition enhanced H2O2-induced apoptosis. Furthermore, repression of Parkin significantly attenuated mitophagy and exacerbated apoptosis. CONCLUSION: These results suggested that Parkin may play a protective role in alleviating the apoptosis of NP cells via mitophagy, and that targeting Parkin may provide a promising therapeutic strategy for the prevention of IDD.

Rickettsia increases its infection and spread in whitefly populations by manipulating the defense patterns of the host plant.

The whitefly Bemisia tabaci is a destructive agricultural pest that frequently harbors various species of secondary symbionts including Rickettsia. Previous studies have revealed that the infection of Rickettsia can improve whitefly performance on food plants; however, to date, no evidence has shown, if, and how, Rickettsia manipulates the plant-insect interactions. In the current study, the effects of Rickettsia persistence on the induced plant defenses and the consequent performance of whitefly B. tabaci were investigated. Results revealed that Rickettsia can be transmitted into plants via whitefly feeding and remain alive within the cotton plants for at least 2 weeks. The different expression genes of cotton plants were mostly concentrated in the phytohormone signaling pathways, the marker genes of jasmonic-acid signaling pathway (AOC, AOS, LOX, MYC2) were significantly downregulated, while the marker genes of the salicylic-acid signaling pathway (WRKY70, PR-1) were upregulated. Biological experiments revealed that the fecundity of Rickettsia negative B. tabaci significantly increased when they fed on Rickettsia-persistent cotton plants. Taken together, we provide experimental evidence that the persistence of Rickettsia and its induced defense responses in cotton plants can increase the fitness of whitefly and, by this, Rickettsia may increase its infection and spread within its whitefly host.

Identification of a new Cordyceps javanica fungus isolate and its toxicity evaluation against Asian citrus psyllid.

The Asian citrus psyllid, Diaphorina citri Kuwayama, is the most serious pest of citrus worldwide. It acts as a vector for a group of phloem-limited bacteria (Candidatus Liberibacter spp.) that causes Huanglongbing (HLB) disease. Thus, D. citri management is an important strategy against HLB, and biological control is currently considered as the most effective method because of the unsustainable and negative side effects of chemical control. Here, we isolated a new strain of entomopathogenic fungus, Cordyceps javanica (GZQ-1), from one cadaver of D. citri adult based on its morphological and phylogenetic data. Five conidial concentrations of the C. javanica pathogen (1 × 103 , 1 × 104 , 1 × 105 , 1 × 106 , and 1 × 107 conidia/ml) were assessed against six life stages of D. citri (1st-5th instar nymphs and adults). Results showed that C. javanica GZQ-1 was highly pathogenic to D. citri nymphs (69.49%-90.87% mortality) and adults (69.98% mortality). The LC50 and LT50 values of C. javanica against 1st-2nd instar (younger), 3rd-4th instar (middle aged), 5th instar (older), and adults were 1.20 × 105 , 1.10 × 106 , 4.47 × 106 , 8.12 × 106 conidia/ml and 4.25, 4.51, 5.17, 5.49 days, respectively. Moreover, glasshouse experiments indicated that this C. javanica GZQ-1 caused higher infection rates of D. citri adults compared to two other fungal strains we previously isolated in the laboratory, Cordyceps fumosorosea (IF010) and Metarhizium anisopliae (CNGD7).

Risk Assessment of Two Insecticides on Encarsia formosa, Parasitoid of Whitefly Bemisia tabaci.

The assessment of acute toxicity to insect natural enemies is very important for insecticide selection used within integrated pest management (IPM). The acute toxicity of abamectin and imidacloprid against Encarsia formosa, a parasitoid of Bemisia tabaci, was investigated. Abamectin had a high toxicity risk to E. formosa, while imidacloprid showed a medium toxicity risk. When treated with the lethal concentration 30 (LC30) of abamectin, the dwelling time of E. formosa in B. tabaci infested-plant-area (IPA) was significantly lower than in non-infested plant areas (non-IPA). In addition, the frequency of E. formosa entering into the two areas was not significantly different in the LC10 and LC30 treatments. Within the IPA, LC10, and LC30 treatments decreased the dwelling time and entering frequency of parasitoid significantly. For imidacloprid treatments, E. formosa stayed a longer time in the non-IPA than in the IPA when treated with LC30. The frequency of E. formosa entering into the two areas was only slightly different in the LC1, LC10, and LC30 treatments. Within the IPA, LC10 and LC30 treatments were significantly decreased in the dwelling time and the entering frequency of E. formosa. The results indicate that abamectin and imidacloprid have high or medium acute toxicity against E. formosa and a negative sublethal effect on its searching behaviour.

Infection dynamics of endosymbionts reveal three novel localization patterns of Rickettsia during the development of whitefly Bemisia tabaci.

The whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) is a severe agricultural pest that harbors at least seven endosymbionts. Many important aspects of the symbiosis mechanism between these bacterial endosymbionts and their hosts are poorly understood, such as endosymbiont proliferation dynamics, spatial distribution and titer regulation during host development. In this study, infection by bacterial endosymbionts in the whitefly B. tabaci Middle East-Asia Minor-1 (MEAM1, formerly B biotype) South China population, their infection titers in various stages of whitefly host development and their spatial localization were investigated. Results revealed that the MEAM1 B. tabaci harbors the primary symbiont Portiera and secondary symbionts Rickettsia and Hamiltonella. The titers of these three endosymbionts increased with the development of their B. tabaci host. Significant proliferation of Portiera and Hamiltonella mainly occurred during the second to fourth instar nymphal stages, while Rickettsia proliferated mainly during adult eclosion. Fluorescence in situ hybridization analysis of B. tabaci adults revealed three novel infection patterns of Rickettsia: assemblage in the bacteriocytes that scattered through the entire abdomen of the female host, localization in wax glands and localization in the colleterial gland. These novel infection patterns may help to uncover the function of Rickettsia in its insect hosts.

Plant-mediated horizontal transmission of Rickettsia endosymbiont between different whitefly species.

A growing number of studies have revealed the presence of closely related endosymbionts in phylogenetically distant arthropods, indicating horizontal transmission of these bacteria. Here we investigated the interspecific horizontal transmission of Rickettsia between two globally invasive whitefly species, Bemisia tabaci MEAM1 and B. tabaci MED, via cotton plants. We found both scattered and confined distribution patterns of Rickettsia in these whiteflies. After entering cotton leaves, Rickettsia was restricted to the leaf phloem vessels and could be taken up by both species of the Rickettsia-free whitefly adults, but only the scattered pattern was observed in the recipient whiteflies. Both the relative quantity of Rickettsia and the efficiency of transmitting Rickettsia into cotton leaves were significantly higher in MEAM1 females than in MED females. The retention time of Rickettsia transmitted from MEAM1 into cotton leaves was at least 5 days longer than that of MED. Phylogenetic analysis based on 16S rRNA and gltA genes confirmed that the Rickettsia extracted from the donor MEAM1, the cotton leaves, the recipient MEAM1 and the recipient MED were all identical. We conclude that cotton plants can mediate horizontal transmission of Rickettsia between different insect species, and that the transmission dynamics of Rickettsia vary with different host whitefly species.

Leptomeningeal carcinomatosis as the initial manifestation of gastric adenocarcinoma: a case report.

Leptomeningeal involvement is usually reported as a secondary event in advanced gastric carcinoma. Leptomeningeal carcinomatosis (LMC), as the initial manifestation of asymptomatic gastric cancer, is exceedingly rare with only a few cases reported in recent years. The presenting neurologic symptoms include headache, vomiting and seizures and are usually clinically atypical. The diagnosis of LMC is made via identification of malignant cells that originate from epithelial cells in the cerebrospinal fluid by cytological examination and provides cues to track the primary tumor. Endoscopic examinations are crucial to confirm the presence of gastric cancer, and imaging studies, especially gadolinium-enhanced magnetic resonance imaging of the brain, are sometimes helpful in diagnosis. Thus far, there is no standard therapy for LMC, and despite all measures, the prognosis of the condition is extremely poor. Here, we report on the clinical features and diagnostic procedures for a patient with occult gastric cancer with Bormann type I macroscopic appearance and poor differentiation in pathology, who presented with LMC-induced neurological symptoms as the initial clinical manifestation. Additionally, we review the similar cases reported over the past years, making comparison among cases in order to provide more information for the future diagnosis.

A review of the genus Serangium Blackburn (Coleoptera, Coccinellidae) from China.

The genus Serangium Blackburn from China is reviewed. The genus Catanella Miyatake is removed from synonymy with Serangium. Serangium baculum Xiao is transferred to Catanella, as Catanella baculum (Xiao), comb. n. Twelve species of Serangium are described, keyed and illustrated, including eight new species, Serangium magnipunctatum Wang & Ren, sp. n., Serangium trimaculatum Wang & Ren, sp. n., Serangium centrale Wang & Ren, sp. n., Serangium leigongicus Wang & Ren, sp. n., Serangium latilobum Wang & Ren, sp. n., Serangium digitiforme Wang & Ren, sp. n., Serangium dulongjiang Wang, Ren & Chen, sp. n., and Serangium contortum Wang & Ren, sp. n.Serangium punctum Miyatake is newly recorded from China.