Chinese decry dishonesty in scientific research

Chinese journals are reporting instances of misconduct by researchers similar to those that have been troubling the American scientific community. Several articles are cited which report cases of fabrication of data, plagiarism, or unfair claims to authorship. A Chinese scientific journal has begun a regular column on ethics in science, and researchers have drafted a code of ethics for the Peking scientific community.     

Characterizing the Saltol Quantitative Trait Locus for Salinity Tolerance in Rice

This study characterized Pokkali-derived quantitative trait loci (QTLs) for seedling stage salinity tolerance in preparation for use in marker-assisted breeding. An analysis of 100 SSR markers on 140 IR29/Pokkali recombinant inbred lines (RILs) confirmed the location of the Saltol QTL on chromosome 1 and identified additional QTLs associated with tolerance. Analysis of a series of backcross lines and near-isogenic lines (NILs) developed to better characterize the effect of the Saltol locus revealed that Saltol mainly acted to control shoot Na⁺/K⁺ homeostasis. Multiple QTLs were required to acquire a high level of tolerance. Unexpectedly, multiple Pokkali alleles at Saltol were detected within the RIL population and between backcross lines, and representative lines were compared with seven Pokkali accessions to better characterize this allelic variation. Thus, while the Saltol locus presents a complex scenario, it provides an opportunity for marker-assisted backcrossing to improve salt tolerance of popular varieties followed by targeting multiple loci through QTL pyramiding for areas with higher salt stress.     

Initial adherence of EPEC,EHEC and VTEC to host cells

Initial adherence to host cells is the first step of the infection of enteropathogenic Escherichia coli (EPEC), enterohaemorrhagic Escherichia coli (EHEC) and verotoxigenic Escherichia coli (VTEC) strains. The importance of this step in the infection resides in the fact that (1) adherence is the first contact between bacteria and intestinal cells without which the other steps cannot occur and (2) adherence is the basis of host specificity for a lot of pathogens. This review describes the initial adhesins of the EPEC, EHEC and VTEC strains. During the last few years, several new adhesins and putative colonisation factors have been described, especially in EHEC strains. Only a few adhesins (BfpA, AF/R1, AF/R2, Ral, F18 adhesins) appear to be host and pathotype specific. The others are found in more than one species and/or pathotype (EPEC, EHEC, VTEC). Initial adherence of EPEC, EHEC and VTEC strains to host cells is probably mediated by multiple mechanisms.     

Population‐level consequences for wild fish exposed to sublethal concentrations of chemicals – a critical review

Concentrated chemical spills have been shown to impact adversely on fish populations and even cause localized population extinctions. Evaluating population‐level impacts of sublethal exposure concentrations is, however, complex and confounded by other environmental pressures. Applying effect measures derived from laboratory‐based chemical exposures to impacts in wild fish populations is constrained by uncertainty on how biochemical response measures (biomarkers) translate into health outcomes, lack of available data for chronic exposures and the many uncertainties in available fish population models. Furthermore, wild fish show phenotypic plasticity and local adaptations can occur that adds geographic and temporal variance on responses. Such population‐level factors are rarely considered in the chemical risk assessment process and can probably be derived only from studies on wild fish. Molecular technologies, including microsatellite and SNP genotyping, and RNASeq for gene expression studies, are advancing our understanding of mechanisms of eco‐toxicological response, tolerance, adaptation and selection in wild populations. We examine critically the application of such approaches with examples including using microsatellites that has identified roach (Rutilus rutilus) populations living in rivers contaminated with sewage effluents that are self‐sustaining, and studies of stickleback (Gasterosteus aculeatus) and killifish (Fundulus heteroclitus) that have identified genomic regions under selection putatively related to pollution tolerance. Integrating data on biological effects between laboratory‐based studies and wild populations, and building understanding on adaptive responses to sublethal exposure are some of the priority research areas for more effective evaluation of population risks and resilience to contaminant exposure.     

In vitro infection of aortic endothelial cells by caprine arthritis encephalitis virus enhances in vitro transmigration of peripheral blood leukocytes and modulates their phenotypic expression

Infection of goats by caprine arthritis-encephalitis virus (CAEV) provides a convenient example of the infiltration of various tissues by leukocytes following a natural lentiviral infection. This event is important in determining organ susceptibility and local immunity. Caprine vascular endothelial cells are susceptible to infection by CAEV in vitro, so we have investigated the consequences of this infection on the transmigration of uninfected leukocytes in an in vitro model. After in vitro infection by CAEV or stimulation by TNFalpha, the endothelial cells allowed the passage of tenfold more leukocytes from uninfected donors than did the uninfected endothelial cells. The transmigrating leukocytes were enriched in CD8+ lymphocytes, and the leukocytes appeared to have been activated during transmigration, as demonstrated by their expression of IL2R, MHC class II antigens and gamma-delta T-lymphocyte markers. CD4+, CD8+ and B-lymphocytes all proliferated in culture after transmigration. These results suggest that any possible infection or specific stimulation of endothelia in an infected animal could profoundly influence the choice of target organs and could activate the cells involved in local mucosal immune responses.     

Immunological differences between layer- and broiler-type chickens

In commercial poultry husbandry, alternatives for the use of antibiotics and vaccines are under investigation, which preferably have to be applicable for both layer- and broiler-type chickens. There are indications that the defense mechanisms vary between layer- and broiler-type chickens. Therefore, the difference in immune response between layer- and broiler-type chickens of the same age was investigated, using TNP-KLH (trinitrophenyl-conjugated keyhole limpet hemocyanin) as antigen without adjuvant. First different routes of immunization (intravenously, intramuscular, subcutaneous and ocular) were examined to find out which immunization route gives the highest antibody titers. The intravenous immunization route resulted in higher TNP-specific antibody responses than the other immunization routes tested and therefore this immunization route was used in both following experiments. In order to investigate the optimal dose of antigen needed for immunization, a dose-response curve in broiler- and layer-type chickens was completed. The humoral immune response was measured in serum by a TNP-specific ELISA and the in vitro cellular immune response by an antigen-specific lymphocyte proliferation assay.The antibody response of layer- and broiler-type chickens appeared to differ, not only in optimal dose and response, but also in kinetics of the response itself. Broiler chickens generated higher IgM anti-TNP titers whereas layer-type chickens generated higher IgG anti-TNP titers. This specific antibody response in broiler-type chickens did not last as long as in layer-type chickens. The TNP-specific cellular immune response was detectable in layer-type chickens, but not in broilers. Both types generate a non-specific cellular immune response, although this response in broilers is lower than in layer-type chickens.From these results, we conclude that broilers primarily respond to TNP-KLH with a high IgM antibody response whereas layer-type chickens respond with a high IgG response. In addition, the cellular response of layer-type chickens is much higher than the response of broilers. The results suggest that broilers are specialized in the production of a strong short-term humoral response and layer-type chickens in a long-term humoral response in combination with a strong cellular response, which is in conformity with their life expectancy.