Transgene × Environment Interactions in Genetically Modified Wheat

BACKGROUND: The introduction of transgenes into plants may cause unintended phenotypic effects which could have an impact on the plant itself and the environment. Little is published in the scientific literature about the interrelation of environmental factors and possible unintended effects in genetically modified (GM) plants. METHODS AND FINDINGS: We studied transgenic bread wheat Triticum aestivum lines expressing the wheat Pm3b gene against the fungus powdery mildew Blumeria graminis f.sp. tritici. Four independent offspring pairs, each consisting of a GM line and its corresponding non-GM control line, were grown under different soil nutrient conditions and with and without fungicide treatment in the glasshouse. Furthermore, we performed a field experiment with a similar design to validate our glasshouse results. The transgene increased the resistance to powdery mildew in all environments. However, GM plants reacted sensitive to fungicide spraying in the glasshouse. Without fungicide treatment, in the glasshouse GM lines had increased vegetative biomass and seed number and a twofold yield compared with control lines. In the field these results were reversed. Fertilization generally increased GM/control differences in the glasshouse but not in the field. Two of four GM lines showed up to 56% yield reduction and a 40-fold increase of infection with ergot disease Claviceps purpurea compared with their control lines in the field experiment; one GM line was very similar to its control. CONCLUSIONS: Our results demonstrate that, depending on the insertion event, a particular transgene can have large effects on the entire phenotype of a plant and that these effects can sometimes be reversed when plants are moved from the glasshouse to the field. However, it remains unclear which mechanisms underlie these effects and how they may affect concepts in molecular plant breeding and plant evolutionary ecology

The cancer genome atlas comprehensive molecular characterization of renal cell carcinoma

Renal cell carcinoma (RCC) is not a single disease, but several histologically defined cancers with different genetic drivers, clinical courses, and therapeutic responses. The current study evaluated 843 RCC from the three major histologic subtypes, including 488 clear cell RCC, 274 papillary RCC, and 81 chromophobe RCC. Comprehensive genomic and phenotypic analysis of the RCC subtypes reveals distinctive features of each subtype that provide the foundation for the development of subtype-specific therapeutic and management strategies for patients affected with these cancers. Somatic alteration of BAP1, PBRM1, and PTEN and altered metabolic pathways correlated with subtype-specific decreased survival, while CDKN2A alteration, increased DNA hypermethylation, and increases in the immune-related Th2 gene expression signature correlated with decreased survival within all major histologic subtypes. CIMP-RCC demonstrated an increased immune signature, and a uniform and distinct metabolic expression pattern identified a subset of metabolically divergent (MD) ChRCC that associated with extremely poor survival

IgG Seroconversion and Pathophysiology in Severe Acute Respiratory Syndrome Coronavirus 2 Infection.

We investigated the dynamics of seroconversion in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. During March 29–May 22, 2020, we collected serum samples and associated clinical data from 177 persons in London, UK, who had SARS-CoV-2 infection. We measured IgG against SARS-CoV-2 and compared antibody levels with patient outcomes, demographic information, and laboratory characteristics. We found that 2.0%–8.5% of persons did not seroconvert 3–6 weeks after infection. Persons who seroconverted were older, were more likely to have concurrent conditions, and had higher levels of inflammatory markers. Non-White persons had higher antibody concentrations than those who identified as White; these concentrations did not decline during follow-up. Serologic assay results correlated with disease outcome, race, and other risk factors for severe SARS-CoV-2 infection. Serologic assays can be used in surveillance to clarify the duration and protective nature of humoral responses to SARS-CoV-2 infection

Thyroid paraganglioma. Report of 3 cases and description of an immunohistochemical profile useful in the differential diagnosis with medullary thyroid carcinoma, based on complementary DNA array results.

Thyroid paraganglioma is a rare disorder that sometimes poses problems in differential diagnosis with medullary thyroid carcinoma. So far, differential diagnosis is solved with the help of some markers that are frequently expressed in medullary thyroid carcinoma (thyroid transcription factor 1, calcitonin, and carcinoembryonic antigen). However, some of these markers are not absolutely specific of medullary thyroid carcinoma and may be expressed in other tumors. Here we report 3 new cases of thyroid paraganglioma and describe our strategy to design a diagnostic immunohistochemical battery. First, we performed a comparative analysis of the expression profile of head and neck paragangliomas and medullary thyroid carcinoma, obtained after complementary DNA array analysis of 2 series of fresh-frozen samples of paragangliomas and medullary thyroid carcinoma, respectively. Seven biomarkers showing differential expression were selected (nicotinamide adenine dinucleotide dehydrogenase 1 alpha subcomplex, 4-like 2, NDUFA4L2; cytochrome c oxidase subunit IV isoform 2; vesicular monoamine transporter 2; calcitonin gene-related protein/calcitonin; carcinoembryonic antigen; and thyroid transcription factor 1) for immunohistochemical analysis. Two tissue microarrays were constructed from 2 different series of paraffin-embedded samples of paragangliomas and medullary thyroid carcinoma. We provide a classifying rule for differential diagnosis that combines negativity or low staining for calcitonin gene-related protein (histologic score, <10) or calcitonin (histologic score, <50) together with positivity of any of NADH dehydrogenase 1 alpha subcomplex, 4-like 2; cytochrome c oxidase subunit IV isoform 2; or vesicular monoamine transporter 2 to predict paragangliomas, showing a prediction error of 0%. Finally, the immunohistochemical battery was checked in paraffin-embedded blocks from 4 examples of thyroid paraganglioma (1 previously reported case and 3 new cases), showing also a prediction error of 0%. Our results suggest that the comparative expression profile, obtained by complementary DNA arrays, seems to be a good tool to design immunohistochemical batteries used in differential diagnosis

Opposing effects of HIF1\u3b1 and HIF2\u3b1 on chromaffin cell phenotypic features and tumor cell proliferation: Insights from MYC-associated factor X.

Pheochromocytomas and paragangliomas (PPGLs) are catecholamine-producing chromaffin cell tumors with diverse phenotypic features reflecting mutations in numerous genes, including MYC-associated factor X (MAX). To explore whether phenotypic differences among PPGLs reflect a MAX-mediated mechanism and opposing influences of hypoxia-inducible factor (HIF)s HIF2 alpha and HIF1 alpha, we combined observational investigations in PPGLs and gene-manipulation studies in two pheochromocytoma cell lines. Among PPGLs from 140 patients, tumors due to MAX mutations were characterized by gene expression profiles and intermediate phenotypic features that distinguished these tumors from other PPGLs, all of which fell into two expression clusters: one cluster with low expression of HIF2 alpha and mature phenotypic features and the other with high expression of HIF2 alpha and immature phenotypic features due to mutations stabilizing HIFs. Max-mutated tumors distributed to a distinct subcluster of the former group. In cell lines lacking Max, re-expression of the gene resulted in maturation of phenotypic features and decreased cell cycle progression. In cell lines lacking Hif2 alpha, overexpression of the gene led to immature phenotypic features, failure of dexamethasone to induce differentiation and increased proliferation. HIF1 alpha had opposing actions to HIF2 alpha in both cell lines, supporting evolving evidence of their differential actions on tumorigenic processes via a MYC/MAX-related pathway. Requirement of a fully functional MYC/MAX complex to facilitate differentiation explains the intermediate phenotypic features in tumors due to MAX mutations. Overexpression of HIF2 alpha in chromaffin cell tumors due to mutations affecting HIF stabilization explains their proliferative features and why the tumors fail to differentiate even when exposed locally to adrenal steroids