Effect of serum amyloid A on invasion,migration and MAPK signaling pathway in osteosarcoma cells

AIM: To investigate the effect of silencing of serum amyloid A (SAA) on the viability, apoptosis, migration and mitogen-activated protein kinase (MAPK) signaling pathway in osteosarcoma U2OS cells. METHODS: Small interfering RNA (siRNA) targeting SAA was transfected into U2OS cells to silence the expression of SAA gene. The U2OS cells were divided into blank control group, negative control group, and experimental group. The cells in negative control group and experimental group were transfected into negative control siRNA and SAA-siRNA, respectively. The cells in blank control group were without any treatment. The viability of the cells was measured by MTT assay and the apoptotic rate was analyzed by flow cytometry with Annexin V-FITC/PI double staining. The migration and invasion abilities of the cells were detected by Transwell chamber assay. The protein levels of SAA, phosphorylated p38 MAPK (p-p38 MAPK) and phosphorylated c-Jun N-terminal kinase (p-JNK) in the cells were determined by Western blot. RESULTS: The protein expression of SAA in SAA-siRNA group was significantly lower than that in blank control group (P<0.05). Compared with blank control group, the cell viability in SAA-siRNA group was significantly decreased (P<0.05), the apoptotic rate was significantly increased (P<0.05), and the invasion and migration abilities were significantly decreased (P<0.05). The protein levels of p-p38 MAPK and p-JNK in SAA-siRNA group were significantly lower than those in blank control group (P<0.05), and no significant difference of total JNK and p38 protein levels was observed. CONCLUSION: Silencing of SAA expression inhibits the viability of osteosarcoma cells, induces apoptosis and decreases the migration of osteosarcoma cells, which may be related to the activation of MAPK signaling pathway.     

海南岛外来入侵生物分析

据调查,海南岛外来入侵生物已达近200种,对当地生物多样性和农林牧渔业造成了严重的影响。随着旅游、商贸和工农业等的迅速发展,外来入侵生物将会越来越多,对生态系统的影响将会更加严重。     

Persistent Acacia savannas replace Mediterranean sclerophyllous forests in South America

Mediterranean ecosystems are global hotspots of biodiversity threaten by human disturbances. Growing evidence indicates that regeneration of Mediterranean forests can be halted under certain circumstances and that successional stages can become notoriously persistent. The Mediterranean sclerophyllous forest in central Chile is been largely transformed into savannas dominated by the invasive legume tree Acacia caven as result of interacting management and ecological factors. We used multi-temporal satellite imagery to study the transition dynamics of these major vegetation types over the last four decades (1975-2008). Vegetation changes were related to indicators of resource availability (topography, water availability, solar radiance), potential propagule availability (distance to forest remnant patches) and disturbance regimes (grazing, fire occurrence and distance to roads and cities). During this study period, forests were mostly converted into Acacia savannas (46.1%). Acacia savanna was the most persistent natural vegetation type. The probability of sclerophyllous forest degradation into Acacia savanna increased on drier northern-exposed slopes, close to roads and further away from forest remnants. In contrast, forest regeneration from Acacia savanna was higher on moister southern-exposed slopes and closer to forest remnants. Acacia savannas are increasingly being converted into cultivated land on the moister locations or switching into a bare soil state in locations close to cities and further away from forest remnants. These results highlight the vulnerability of diverse sclerophyllous forests and its increasing conversion into persistent Acacia savannas in the Mediterranean region of central Chile and identify the ecological conditions for successful conservation and restoration of the native sclerophyllous forest vegetation that can be used for sensible land use planning.     

Influence of temperature on the motility of Pseudomonas oryzihabitans and control of Globodera rostochiensis

The motility and efficacy of Pseudomonas oryzihabitans as a biocontrol agent against the potato cyst nematode Globodera rostochiensis were studied with respect to temperature. The influence of soil moisture on bacterial movement was also tested. In a closed container trial, P. oryzihabitans significantly reduced invasion of second stage juveniles (J2) of G. rostochiensis in potato roots, its effect being more marked at 25 and 21 °C than at 17 °C. P. oryzihabitans motility in vitro was optimal at 26 °C and inhibited at temperatures below 18 °C. In soil, both temperature and matric potential affected bacterial movement. At 16 °C its movement and survival were suppressed, but they were unaffected at 25 °C. At both temperatures the biocontrol agent moved faster in the wetter (−0.03 MPa) than in the drier soil (−0.1 MPa). These results suggest that temperature is a key factor in determining the potential of P. oryzihabitans as a biocontrol agent.     

Recovery of native plant communities after the control of a dominant invasive plant species, Foeniculum vulgare: Implications for management

The control and/or removal of a dominant invasive species is expected to lead to increases in native species richness and diversity. Small pilot studies were performed on Santa Cruz Island (SCI), California, in the early 1990s to test the efficacy of different methods on the control of Foeniculum vulgare (fennel) and management’s effects on native species recovery. We chose a treatment that showed significant native species recovery, applied it at the landscape scale, and followed its effects on fennel infested plant communities. We tested the hypothesis that results from small-scale studies translate to the landscape level. We found that although the control of fennel translated from the small to landscape scale, decreasing from an average of 60% to less than 3% cover, native species recovery did not occur in the landscape study as it did in the pilot studies. Invasive fennel cover was replaced by non-native grass cover over time. Unexpectedly, fennel cover in untreated fennel plots decreased significantly (though not as drastically) from over 60% cover to just under 40% cover while native species richness in untreated areas increased significantly. The correlation between precipitation and changes in native and non-native species richness and abundance in this study imply that changes in species abundances were highly correlated with environmental fluctuations. The lack of a native seedbank and the accumulation of non-native grass litter likely prevented the recovery of native species in treated areas. Greater vertical complexity found in fennel communities, which increased visitation by frugivorous birds and likely increased native seed dispersal, may have been responsible for the increase in native species richness in the untreated areas. These results suggest that successful invasive species control and native species recovery experiments conducted at small scales may not translate to the landscape level, and active restoration should be an organic component of such large-scale projects.     

Identification of 12 EST-derived SSR markers in Lumbricus rubellus

While many species of earthworms are globally distributed, very little is known about the genetic population dynamics of this diverse group. We present the characterization of novel simple sequence repeat (SSR) markers, including primer information, number of alleles, repeat motif, and approximate size ranges, to be used in population genetic analyses of the earthworm Lumbricus rubellus Hoffmeister 1843. Specifically, we designed and characterized 12 novel, polymorphic markers derived from published expressed sequence tags (EST) for amplification in L. rubellus. The mean number of alleles per locus was 6.25 ± 1.91, indicating these markers will be sufficiently polymorphic for population genetic studies of this species.     

Effects of urbanization on California’s fish diversity: Differentiation, homogenization and the influence of spatial scale

Human development of freshwater ecosystems has lead to drastic changes in freshwater fish faunas, including the loss of many native species and the gain of non-natives. Typically conservation ecologists view these two opposing forces as contributing to biological homogenization, and consider homogenization as one of the principle negative consequences of urbanization. However, homogenization is only one outcome out of many that can result from the loss and gain of species. In particular, it is possible for invasions and extinctions to lead to differentiation; a process whereby two (or more) regions become less similar to one another through time. Using the freshwater fishes of California, we show that urbanization is highly positively correlated to both the endangerment of native fish and the invasion of non-native fish within watersheds. Despite this, the fish faunas of California’s watersheds have differentiated from one another through time. Furthermore, the degree of differentiation is positively correlated with measures of urbanization, which is contrary to expectation. We suggest that this result reflects: (1) the haphazard manner in which non-native fishes have been introduced into California watersheds, (2) the difficulty that both native and non-native fishes have in expanding their geographical ranges, and (3) the continued presence of vestiges of formerly distinct regional faunas. This pattern of differentiation among watersheds is likely a matter of scale, as previous work on freshwater fishes has demonstrated homogenization at both larger and smaller spatial scales. In addition the observed pattern is probably a short-term (temporal) phenomena and will disappear with continued invasion and extinction. We suggest that similar patterns may occur for other taxa that have limited natural dispersal abilities and that are idiosyncratically released as non-natives via human activities (e.g. herptiles).     

Progress of ELMO family on malignant tumor invasion and metastasis

It is one of the main characters of malignant tumors that malignant tumor cells invade surrounding tissues and metastasize to distant tissues. Multiple factors are involved in this complicated dynamic process. Metastasis is the major factor influencing recurrence and prognosis. Therefore, it is important to explore the mechanism of invasion and metastasis for reducing recurrence rate and mortality of malignant tumors. Engulfment and cell mobility (ELMO) family is one kind of conserved protein in evolutional process. It includes 3 members, ELMO1, ELMO2 and ELMO3. The members of ELMO family play an important role in cell phagocytosis and cell migration, and they also have close correlation with malignant tumor cell invasion and metastasis. In this paper, we review the progress of the relationship between ELMO family and malignant tumor invasion and metastasis.     

寡糖对向日葵锈菌侵染的影响

为了明确寡糖对向日葵锈菌侵染的影响,在向日葵苗期用寡糖处理并接菌后对锈菌夏孢子的萌发率和侵入率以及气孔开闭进行了观察,并用甲苯胺蓝染色法对入侵位点酚类化合物的积累进行了检测。试验结果表明,与对照相比寡糖处理后锈菌夏孢子的萌发率和侵入率均显著降低,而气孔关闭率显著升高。同时,在接种后12 h时,大量的侵入位点产生了酚类化合物的积累,说明寡糖处理可以有效抑制向日葵锈菌的侵染。     

危害棉花的入侵生物扶桑绵粉蚧研究

综述了一种危害棉花的入侵生物扶桑绵粉蚧的形态、生物学特性、危害情况、入侵与扩散、在我国的潜在危害以及防控方法,展望了扶桑绵粉蚧未来的研究方向,