Exorista sorbillans (Diptera: Tachinidae) parasitism shortens host larvae growth duration by regulating ecdysone and juvenile hormone titers in Bombyx mori (Lepidoptera: Bombycidae).

The tachinid fly, Exorista sorbillans, is a notorious ovolarviparous endoparasitoid of the silkworm, Bombyx mori, causing severe damage to silkworm cocoon industry. Silkworm larvae show typically precocious wandering behavior after being parasitized by E. sorbillans; however, the underlying molecular mechanism remains unexplored. Herein, we investigated the changes in the levels of 20-hydroxyecdysone (20E) and juvenile hormone (JH) titer, and they both increased in the hemolymph of parasitized silkworms. Furthermore, we verified the expression patterns of related genes, which showed an upregulation of 20E signaling and biosynthesis genes but a significant downregulation of ecdysone oxidase (EO), a 20E inactivation enzyme, in parasitized silkworms. In addition, related genes of the JH signaling were activated in parasitized silkworms, while related genes of the JH degradation pathway were suppressed, resulting in an increase in JH titer. Notably, the precocious wandering behavior of parasitized silkworms was partly recoverable by silencing the transcriptions of BmCYP302A1 or BmCYP307A1 genes. Our findings suggest that the developmental duration of silkworm post parasitism could be shortened by regulation of 20E and JH titers, which may help silkworm to resist the E. sorbillans infestation. These findings provide a basis for deeper insight into the interplay between silkworms and E. sorbillans and may serve as a reference for the development of a novel approach to control silkworm myiasis.

Cordyceps cicadae polysaccharides inhibit human cervical cancer hela cells proliferation via apoptosis and cell cycle arrest.

The present study presented the extraction and purification of polysaccharides from artificially cultured Cordyceps cicadae and wild Cordyceps cicadae by pre-soaking ultrasonic water extraction. The effects of different concentrations of polysaccharides on proliferation and cytotoxicity of Hela cells were detected by MTT and LDH methods. The results showed that the proliferation of Hela cells was inhibited by polysaccharides treatment (25 µg/mL-1600 µg/mL). The results of flow cytometry further confirmed that polysaccharides blocked the cell cycle in the S phase and promoted apoptosis. RT-qPCR and Western Blot were used to study the mRNA and protein expression of genes related to cell cycle and apoptosis signaling pathway. The results showed that polysaccharides treatment inhibited the expression of Cyclin E, Cyclin A and CDK2 and up regulated the expression of P53. Further, activation of Caspase cascade reaction, up regulation of death receptor, and the ratio of pro-apoptotic factor/anti-apoptotic factors, thus caused the cell cycle arrest and induced the apoptosis. The above research results lay a foundation for extending the anti-cancer effects of natural plant resources with low toxicity and high efficiency.

Genetic diversity and reproductive success of a wild population of Chinese sturgeon ( Acipenser sinensis) from the Yangtze River inferred from juveniles born in 2014.

The Chinese sturgeon ( Acipenser sinensis Gray, 1835) is a large anadromous fish species, which is under considerable threat due to dramatic declines in population numbers. In the current study, population genetic diversity and individual reproductive success were assessed using nuclear microsatellite markers (simple sequence repeat, SSR) and complete mitochondrial (mtDNA) genome analysis of juveniles born in 2014. Results showed the existence of size polymorphism in the mtDNA genome of Chinese sturgeon, which was caused by a repeat motif. Population genetic diversity was high based on both SSR ( Ho: 0.728±0.211; He: 0.779±0.122) and mtDNA genome analyses ( H: 0.876±0.0035; Pi: 0.0011±0.0010). A positive inbreeding coefficient ( FIS: 0.066±0.143) was also found, indicating the occurrence of inbreeding. Reconstruction of sibling groups identified 11 mothers and 11 fathers involved in reproduction of Chinese sturgeons in 2014. Variance in individual reproductive success was not significant, with reproductive success of parent fish instead shown to be relatively even ( P=0.997>0.05), thus suggesting the absence of sweepstakes reproductive success (SRS). These results indicate that, in regard to conservation, loss of genetic diversity due to the effects of SRS is not of particular concern. However, we must focus on having an adequate number of adults and suitable environmental conditions to ensure that fish can reproduce.

[Effects of light intensities on growth,physiological characteristic and chemical composition of Viola yedoensis].

The study is aimed to investigate the effects of light intensities on growth,photosynthetic physiology,antioxidant systems and chemical composition of Viola yedoensis and provide cultivation references for V.yedoensis.Five groups of V.yedoensis were planted under five light intensities conditions,namely 100%,80%,50%,35%,5%of full sunlight,and then morphological index,growth,chlorophyll fluorescence parameters,photosynthetic parameters and antioxidant enzyme system indexes were measured during harvest.The results showed that there was no significant difference in the biomass of V.yedoensis among 35% -100%full sunlight,but the biomass of those were significantly higher than that in the 5%full sunlight treatment(P<0.05).The net photosynthetic rate,transpiration rate,stomatal conductance,intercellular CO_2 concentration and water use efficiency increased firstly and then decreased with the decrease of light intensity;F_m,F_v/F_mand Yield in 5% full sunlight treatment were significantly lower than those in the other four groups(P<0.05).The structure of chloroplast was normal under light intensity ranged from 50%to 100% full sunlight.The lamellar concentration of chloroplast matrix decreased and the starch granules decreased in 35% full sunlight treatment,and the margin of lamellar layer of chloroplast and substrate were blurred,and the starch granules were small and the number of starch granules decreased significantly under 5% full sunlight.MDA content in 5%full sunlight treatment was significantly higher than those in the other four groups(P<0.05).The total coumarin content and total flavonoid content decreased with the decrease of light intensity.In summary,the light in-tensity range suitable for the growth of V.yedoensis is wide(ranging from 35% to 100% full sunlight).The content of flavonoids and coumarins is positively correlated with light intensity.

A comparison of virus genome sequences with their host silkworm, Bombyx mori.

With the recent availability of the genomes of many viruses and the silkworm, Bombyx mori, as well as a variety of Basic Local Alignment Search Tool (BLAST) programs, a new opportunity to gain insight into the interaction of viruses with the silkworm is possible. This study aims to determine the possible existence of sequence identities between the genomes of viruses and the silkworm and attempts to explain this phenomenon. BLAST searches of the genomes of viruses against the silkworm genome were performed using the resources of the National Center for Biotechnology Information. All studied viruses contained variable numbers of short regions with sequence identity to the genome of the silkworm. The short regions of sequence identity in the genome of the silkworm may be derived from the genomes of viruses in the long history of silkworm-virus interaction. This study is the first to compare these genomes, and may contribute to research on the interaction between viruses and the silkworm.

Early responses of silkworm midgut to microsporidium infection--A Digital Gene Expression analysis.

Host-pathogen interactions are complex processes, which have been studied extensively in recent years. In insects, the midgut is a vital organ of digestion and nutrient absorption, and also serves as the first physiological and immune barrier against invading pathogenic microorganisms. Our focus is on Nosema bombycis, which is a pathogen of silkworm pebrine and causes great economic losses to the silk industry. A complete understanding of the host response to infection by N. bombycis and the interaction between them is necessary to prevent this disease. Silkworm midgut infected with N. bombycis is a good model to investigate the early host responses to microsporidia infection and the interaction between the silkworm and the microsporidium. Using Digital Gene Expression analysis, we investigated the midgut transcriptome profile of P50 silkworm larvae orally inoculated with N. bombycis. At 6, 12, 18, 24, 48, 72, and 96 h post-infection (hpi), 247, 95, 168, 450, 89, 80, and 773 DEGs were identified, respectively. KEGG pathway analysis showed the influence of N. bombycis infection on many biological processes including folate biosynthesis, spliceosome, nicotinate and nicotinamide metabolism, protein export, protein processing in endoplasmic reticulum, lysosome, biosynthesis of amino acids, ribosome, and RNA degradation. In addition, a number of differentially expressed genes involved in the immune response were identified. Overall, the results of this study provide an understanding of the strategy used by silkworm as a defense against the invasion by N. bombycis. Similar interactions between hosts and pathogens infection may exist in other species.

Differentially expressed genes in the cuticle and hemolymph of the silkworm, Bombyx mori, injected with the fungus Beauveria bassiana.

The most important pathogenic fungus of the silkworm, Bombyx mori L. (Lepidoptera: Bombycidae), is Beauveria bassiana (Balsamo-Crivelli ) Vuillemin (Hypocreales: Clavicipitaceae), which causes significant damage to sericulture production. Therefore, diagnosing fungal disease and developing new control measures are crucial to silk production. To better understand the responsive and interactive mechanisms between the host silkworm and this fungus, variations in silkworm gene expression were investigated using the suppression subtractive hybridization method following the injection of B. bassiana conidia. Two cDNA libraries were constructed, and 140 cDNA clones were isolated. Of the 50 differentially expressed genes identified, 45 (112 clones) were identified in the forward library, and 5 (28 clones) were identified in the reverse library. Expression profiling of six of these genes by quantitative polymerase chain reaction (qPCR) verified that they were induced by the fungal challenge. The present study provides insight into the interaction between lepidopteran insects and pathogenic fungi.

Novel protein of IBP from silkworm, Bombyx mori, involved in cytoplasmic polyhedrosis virus infection.

In the present study, the full-length cDNA of a novel insulin-related peptide-binding protein (named BmIBP2) was identified from silkworm, Bombyx mori, using rapid amplification of cDNA ends. The full-length cDNA of BmIBP2 is 1293 bp, consisting of a 5'-terminal untranslated region (UTR) of 61 bp, and a 3'-UTR of 335 bp with a poly-adenylation signal sequence AATAAA and a poly (A) tail. The BmIBP2 cDNA encodes a polypeptide of 298 amino acids, including an IG domain and an IGc2 domain, with a theoretical isoelectric point of 5.73 and a predicted molecular weight of 33.1 kDa. The BmIBP2 also has a signal peptide of 23 amino acids and a potential N-glycosylation site. The sequence similarity and phylogenic analysis indicated that BmIBP2 belongs to the group of invertebrates IBP and is closer to IGFBP7 than to the other IGFBPs in vertebrates. These findings suggest that BmIBP2 is a putative homolog of vertebrate endocrine factor IGFBP7 and has a functional similarity. By fluorescent quantitative real-time polymerase chain reaction, mRNA transcripts of BmIBP2 were mainly detected in the midgut but were hardly detectable in the hemocytes, vasa mucosa, fat body, silk gland, head, testicle, ovary, and spiracle. After the silkworm larvae were infected by B. mori cytoplasmic polyhedrosis virus (BmCPV), a significant up-regulation in the relative expression level of BmIBP2 was found. All the results suggested that BmIBP2 is a novel protein that plays an important role in the insulin-signal pathway and in the immune response of silkworm to BmCPV infection.

[Effects of retained needling and non-retained needling on regulation of the cardiac autonomic nerve].

OBJECTIVE: To investigate the mechanism of retained needling and non-retained needling on the physiologic regulating effect of the cardiac autonomic nerve in healthy persons. METHODS: Sixty volunteers were randomly divided into a retained needling group and a non-retained needling group, 30 cases in each group. They were all received perpendicular needling at Neiguan (PC 6) and Jianshi (PC 5) retaining for 20 min in the retained nee dling group and without retaining in the non-retained needling group. The heart rate variability (HRV) indices, i.e., R-R interval, low frequency (LF), high frequency (HF) and LF/HF were observed. RESULTS: Compared with before acupuncture, the R-R interval were significant increased during the stimulation period and during the post-stimulation period in the retained needling group, especially during the stimulation period (all P < 0.01), and during the post-stimulation period of 5 min and 10 min in the non-retained needling group (P < 0.01, P < 0.05), then returned to pre-acupuncture level quickly, and the R-R interval in the retained needling group was significant ly higher than that in the non retained needling group at 10 min (P < 0.05). At 5 min, the HF were significantly higher, and the LF/HF were significantly lower than those before acupuncture (P < 0.01, P < 0.05), and there was no obvious change in LF in both groups. CONCLUSION: Retained needling and non-retained needling at Neiguan (PC 6) and Jianshi (PC 5) can both excite cardiac vagus nerve briefly and then the acupuncture effects reduce grad ually until disappearance, while no obvious changes can be found with cardiac sympathetic activity. Both of needling can reduce heart rate and the action time of heart rate decrease by retained needling is longer than non-retained needling.

Isolation and identification of a pathogen of silkworm Bombyx mori.

A pathogenic bacterial strain, ST-1, was isolated from a naturally infected silkworm. The strain was identified on the basis of its physiological and biochemical properties and the results of sequence analysis of its 16S rRNA gene. The results of the 16S rRNA gene sequence analysis revealed that ST-1 shared the highest sequence identity (more than 99%) with Pseudomonas chlororaphis subsp. aurantiaca. ST-1 bacteria were gram-negative and 0.7-0.9 × 1.3-1.5 µm long, short rods with rounded ends. The strain could utilize sodium citrate, malonate, D-glucose, sucrose, D-fructose, D-mannose, and L-arabinose. Pathogenicity of ST-1 for silkworm could be depicted as a linear regression of the logarithm (y) of ST-1 concentration against probability (x) (y = 0.4040 + 0.0600x). The median lethal concentration (LC(50)) was 2.12 × 10(4) cfu/ml. In conclusion, ST-1 was identified as Ps. chlororaphis subsp. aurantiaca. This is the first report that Ps. aurantiaca is a pathogen for silkworm Bombyx mori.

[Prognostic value of electroencephalographic background patterns in full-term neonates with asphyxia].

OBJECTIVE: Severe asphyxia during peripartum may lead to some sequela of the nervous system. Currently the neurologic outcome of asphyxiated neonates is assessed by using imaging techniques such as cranial ultrasound, CT and MRI except for evaluating perinatal abnormal factors and routine physical examinations of nervous system. These assessment approaches are based on the changes of anatomic structures of neonates. Electroencephalography (EEG) can show early abnormal cerebral functions. This study examined the EEG background activity and investigated the parameters associated with the prognostic assessment in full-term neonates with asphyxia. METHODS: A standard EEG was recorded in 49 asphyxiated full-term neonates aged from 24 hrs to 8 days. Of the 49 neonates, 14 had concurrent mild, 5 had moderate and 9 had severe hypoxic-ischemic encephalopathy (HIE). Thirty-one aged-matched full-term neonates without asphyxia severed as the control group. Forty-three of 49 asphyxiated neonates were followed-up for neurological development for 6-12 months. Important parameters associated with neurological prognosis were evaluated by the principle of data statistics. RESULTS: The mean interburst intervals was prolonged, the amplitude of brain electrical activity during all the states were lower, and the incidence of brief burst and sleep-wake cycle disturbance was higher in the asphyxiated group when compared with the control group (P < 0.05). In the follow-up, 4 infants had poor fine motor function and 7 showed retarded psychomotor development in the asphyxiated group. Gestational age, birth weightamplitude of brain electrical activity, severity of HIE, occurrence of sleep-wake cycle disturbance and imaging abnormality were shown as important parameters for predicting neurological outcomes in asphyxiated neonates. The infants who EEG showed isoelectric tracings or isoelectric tracings accompanied with much abnormal discharge had very poor prognosis. CONCLUSIONS: EEG background pattern is valuable in predicting neurological outcomes for term neonates with asphyxia. EEG in combination with clinic data such as gestational age, birth weight, imaging examination, and severity of HIE may provide an accurate evaluation of neurological outcome.