摘要: Species introduced to habitats outside their native range often escape control by their natural enemies. Besides competing with native species, an alien species might also affect the native herbivores by introducing a new source of different quality food. Here, we describe the case of northern red oak (Quercus rubra) invasion in Europe. We collected data on insect (moth Cydia spp. and weevil Curculio spp.) seed predation of northern red oak in its native (USA, North America) and invasive (Poland, Europe) range, as well as for sessile oaks (Quercus petrea) in Europe. We also evaluated the quality of acorns as hosts for weevil larvae by collecting infested acorns and measuring weevil developmental success, and quantifying acorn traits such as seed mass, tannins, lipids and protein concentration. We used DNA barcoding to identify insects to the species level. The predation by moths was similar and very low in both species and in both ranges. However, red oaks escape pre-dispersal seed predation by weevils in Europe. Weevil infestation rates of northern red oak acorns in their invasive range were 10 times lower than that of sessile oaks, and also 10 times lower than that of red oaks in North America. Furthermore, even when weevils oviposited into northern red oaks, the larvae failed to develop, suggesting that the exotic host created a trap for the insect. This phenomenon might gradually decrease the local abundance of the seed predator, and further aid the invasion.

摘要: Phrynocephalus guinanensis has sexual dimorphism in abdominal coloration, but its ontogenetic development of sexual size dimorphism (SSD) is unknown. Using mark-recapture data during four days each year from August from 2014 to 2016, we investigated the development of sex ratios, SSD, sex-specific survivorship and growth rates in a population of P. guinanensis. Our results indicated that the sex ratio of males to females was 1:2.8. Males had a lower survival rate (6%) than females (14%) across the age range from hatchling to adult, which supported the discovered female-biased sex ratio potentially associated with the low survival rate of males between hatchlings and juveniles. Male-biased SSD in tail length and head width existed in adults rather than in hatchling or juvenile lizards. The growth rates in body dimensions were undistinguishable between the sexes during the age from hatchling to juvenile, but the growth rate in head length from juvenile to adult was significantly larger in males than females. Average growth rate of all morphological measurements from hatchling to juvenile were larger compared with corresponding measurements from juvenile to adult, but only being significant in tail length, head width, abdomen length in females and snout-vent length in males. We provided a case study to strengthen our understanding of the important life history traits on how a viviparous lizard population can survive and develop their morphology in cold climates.

摘要: ObjectivesThymidine kinase 1 (TK1) is one of the salvage enzymes engaged in the synthesis of DNA. Although a pro-carcinogenetic role of TK1 has been reported in various types of cancers, its role in pancreatic ductal adenocarcinoma (PDAC) is still unknown. The study is aimed to elaborate the function of TK1 in PDAC and the potential mechanisms in the following study. Materials and methodsTK1 expression was analysed by immunohistochemistry, real-time PCR and Western blot, and its relationship with clinicopathological characteristics of PDAC patients was further investigated. To verify the function of TK1 and potential mechanism, TK1 siRNA was used to transfect PDAC cells and performed a series of assays in cell and animal models. ResultsThe level of TK1 expression was higher in cancerous tissues compared with matched adjacent tissues. TK1 overexpression was associated with progression of PDAC and poor prognosis. Knockdown of TK1 could suppress cell proliferation via inducing S phase arrest mediated by upregulation of P21. Further mechanism investigation suggested that transcription factor E2F-1 could directly regulate the TK1 and promote tumour proliferation. ConclusionsThe results suggested that TK1 might be involved in the development and progression of PDAC by regulating cell proliferation and show that TK1 may work as a promising therapeutic target in patients with PDAC.

摘要: ObjectivesIn our previous reports, we have demonstrated that extremely low-frequency electromagnetic fields (ELF-EMF) exposure enhances the proliferation of keratinocyte. The present study aimed to clarify effects of ELF-EMF on wound healing and molecular mechanisms involved, using a scratch in vitro model. Materials and methodsThe wounded monolayer cultures of human immortalized keratinocytes (HaCaT), at different ELF-EMF and Sham exposure times were monitored under an inverted microscope. The production and expression of IL-1, TNF-, IL-18 and IL-18BP were measured by enzyme-linked immunosorbent assay and quantitative real-time PCR. The activity and the expression of matrix metalloproteinases (MMP)-2/9 was evaluated by zymography and Western blot analysis, respectively. Signal transduction proteins expression (Akt and ERK) was measured by Western blot. ResultsThe results of wound healing in vitro assay revealed a significant reduction of cell-free area time-dependent in ELF-EMF-exposed cells compared to Sham condition. Gene expression and release of cytokines analysed were significantly increased in ELF-EMF-exposed cells. Our results further showed that ELF-EMF exposure induced the activity and expressions of MMP-9. Molecular data showed that effects of ELF-EMF might be mediated via Akt and ERK signal pathway, as demonstrated using their specific inhibitors. ConclusionsOur results highlight ability of ELF-EMF to modulate inflammation mediators and keratinocyte proliferation/migration, playing an important role in wound repair. The ELF-EMF accelerates wound healing modulating expression of the MMP-9 via Akt/ERK pathway.

摘要: ObjectivesThe role of vitamin D (VD) in innate and adaptive immune responses to tuberculosis is still unclear. Our research was aimed to uncover the effect of VD on Th17 cells and elucidate potential molecular mechanism. Materials and methodsVDR-deficient and wild-type mice were used to obtain CD4 T cells. Th17 cells were induced and activated by Bacillus Calmette Guerin. Flow cytometry was used to analyse the apoptosis rate and degree of differentiation of Th17 cells in the treatment of 1,25(OH)(2)D-3. The interaction between P65 and Rorc was determined by immunofluorescence assay, luciferase reporter assay, EMSA-Super-shelf assay and ChIP assay. Co-IP assay was carried out to test the interaction between VDR and NF-B family proteins. qRT-PCR and Western blot were also performed to detect the levels of P65, RORt and IL-17. ResultsThe Th17 cells differentiation was suppressed by 1,25(OH)(2)D-3 in vitro. We confirmed that Rorc was a downstream gene of the transcription factor P65. VDR interacts with P105/P50, P100/P52 and P65 NF-B family proteins. 1,25(OH)(2)D-3 inhibited the expression of RORt/IL-17 by suppressing p65 transcription factor translocating to nucleus. In vivo experiments, the expression of IL-17 and RANKL was suppressed by 1,25(OH)(2)D-3 by VD receptor. Moreover, 1,25(OH)(2)D-3 suppressed the inflammatory infiltrates and inhibited the expression of P65, RORt and IL-17 in the spleen tissues of model mice. ConclusionsTogether, 1,25(OH)(2)D-3 suppressed the differentiation of Th17 cells via regulating the NF-B activity.