Illumina Next Generation Sequencing for the Analysis of Populations in Commercial Broilers and Indigenous Chickens

Eimeria species parasites can cause the enteric disease coccidiosis, most notably in chickens where the economic and welfare implications are significant. Seven Eimeria species are recognized to infect chickens, although understanding of their regional occurrence, abundance and population structure remains limited. Reports of Eimeria circulating in chickens across much of the southern hemisphere with cryptic genotypes and the capacity to escape current anticoccidial vaccines have revealed unexpected levels of complexity. Consequently, it is important to supplement validated species-specific molecular diagnostics with new genus-level tools. Here, we report the application of Illumina MiSeq deep sequencing to partial 18S rDNA amplicons generated using Eimeria genus-specific primers from chicken caecal contents collected in India. Commercial Cobb400 broiler and indigenous Kadaknath type chickens were sampled under field conditions after co-rearing (mixed type farms, n=150 chickens for each) or separate rearing (single type farms, n=150 each). Comparison of MiSeq results with established Internal Transcribed Spacer (ITS) and Sequence Characterised Amplified Region (SCAR) quantitative PCR assays suggest greater sensitivity for the MiSeq approach. The caecal-dwelling Eimeria tenella and E. necatrix dominated each sample set, although all seven species which infect chickens were detected. Two of the three cryptic Eimeria genotypes were detected including OTU-X and OTU-Y, the most northern report for the latter to date. Low levels of DNA representing other Eimeria species were detected, possibly representing farm-level contamination with non-replicating oocysts or Eimeria DNA, or false positives, indicating a requirement for additional validation. Next generation deep amplicon sequencing offers a valuable resource for future Eimeria studies

Gamma secretase inhibition promotes hypoxic necrosis in mouse pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDA) is a highly lethal disease that is refractory to medical intervention. Notch pathway antagonism has been shown to prevent pancreatic preneoplasia progression in mouse models, but potential benefits in the setting of an established PDA tumor have not been established. We demonstrate that the gamma secretase inhibitor MRK003 effectively inhibits intratumoral Notch signaling in the KPC mouse model of advanced PDA. Although MRK003 monotherapy fails to extend the lifespan of KPC mice, the combination of MRK003 with the chemotherapeutic gemcitabine prolongs survival. Combination treatment kills tumor endothelial cells and synergistically promotes widespread hypoxic necrosis. These results indicate that the paucivascular nature of PDA can be exploited as a therapeutic vulnerability, and the dual targeting of the tumor endothelium and neoplastic cells by gamma secretase inhibition constitutes a rationale for clinical translation

Timing of Initiation of Antiretroviral Drugs during Tuberculosis Therapy

The rates of death are high among patients with coinfection with tuberculosis and the human immunodeficiency virus (HIV). The optimal timing for the initiation of antiretroviral therapy in relation to tuberculosis therapy remains controversial

Common variants in CLDN2 and MORC4 genes confer disease susceptibility in patients with chronic pancreatitis

A recent Genome-wide Association Study (GWAS) identified association with variants in X-linked CLDN2 and MORC4 and PRSS1-PRSS2 loci with Chronic Pancreatitis (CP) in North American patients of European ancestry. We selected 9 variants from the reported GWAS and replicated the association with CP in Indian patients by genotyping 1807 unrelated Indians of Indo-European ethnicity, including 519 patients with CP and 1288 controls. The etiology of CP was idiopathic in 83.62% and alcoholic in 16.38% of 519 patients. Our study confirmed a significant association of 2 variants in CLDN2 gene (rs4409525—OR 1.71, P = 1.38 x 10-09; rs12008279—OR 1.56, P = 1.53 x 10-04) and 2 variants in MORC4 gene (rs12688220—OR 1.72, P = 9.20 x 10-09; rs6622126—OR 1.75, P = 4.04x10-05) in Indian patients with CP. We also found significant association at PRSS1-PRSS2 locus (OR 0.60; P = 9.92 x 10-06) and SAMD12-TNFRSF11B (OR 0.49, 95% CI [0.31–0.78], P = 0.0027). A variant in the gene MORC4 (rs12688220) showed significant interaction with alcohol (OR for homozygous and heterozygous risk allele -14.62 and 1.51 respectively, P = 0.0068) suggesting gene-environment interaction. A combined analysis of the genes CLDN2 and MORC4 based on an effective risk allele score revealed a higher percentage of individuals homozygous for the risk allele in CP cases with 5.09 fold enhanced risk in individuals with 7 or more effective risk alleles compared with individuals with 3 or less risk alleles (P = 1.88 x 10-14). Genetic variants in CLDN2 and MORC4 genes were associated with CP in Indian patients

Selective Processing and Metabolism of Disease-Causing Mutant Prion Proteins

Prion diseases are fatal neurodegenerative disorders caused by aberrant metabolism of the cellular prion protein (PrPC). In genetic forms of these diseases, mutations in the globular C-terminal domain are hypothesized to favor the spontaneous generation of misfolded PrP conformers (including the transmissible PrPSc form) that trigger downstream pathways leading to neuronal death. A mechanistic understanding of these diseases therefore requires knowledge of the quality control pathways that recognize and degrade aberrant PrPs. Here, we present comparative analyses of the biosynthesis, trafficking, and metabolism of a panel of genetic disease-causing prion protein mutants in the C-terminal domain. Using quantitative imaging and biochemistry, we identify a misfolded subpopulation of each mutant PrP characterized by relative detergent insolubility, inaccessibility to the cell surface, and incomplete glycan modifications. The misfolded populations of mutant PrPs were neither recognized by ER quality control pathways nor routed to ER-associated degradation despite demonstrable misfolding in the ER. Instead, mutant PrPs trafficked to the Golgi, from where the misfolded subpopulation was selectively trafficked for degradation in acidic compartments. Surprisingly, selective re-routing was dependent not only on a mutant globular domain, but on an additional lysine-based motif in the highly conserved unstructured N-terminus. These results define a specific trafficking and degradation pathway shared by many disease-causing PrP mutants. As the acidic lysosomal environment has been implicated in facilitating the conversion of PrPC to PrPSc, our identification of a mutant-selective trafficking pathway to this compartment may provide a cell biological basis for spontaneous generation of PrPSc in familial prion disease

Small RNA profiling of virus-infected grapevines: evidences for virus infection-associated and variety-specific miRNAs

Grapevine is one of the economically and culturally important perennial fruit crops. More than 60 viruses infect grapevines and adversely affect their growth and development. Latent infection of most viruses in grapevines leads to chronic modulation of gene expression at transcriptional and post-transcriptional levels. Plant small RNAs (sRNAs) consist of microRNA (miRNA) and small interfering RNA (siRNA). miRNAs are expressed from the plant genome while most siRNAs are derived from double-stranded RNA molecules which are intermediates during virus replication. In a previous study, we constructed four cDNA libraries of sRNAs that were enriched from three virus-infected grapevines and one virus-free grapevine. Majority of siRNAs align most closely with the genomes of DNA viruses in the genus Badnavirus, family Caulimoviridae that led to the discovery of a new Grapevine vein clearing virus in grapevines. In this study, we conducted a comprehensive analysis of miRNAs in the four cDNA libraries and identified novel and stress-related miRNAs. The results indicated that miRNA abundance was influenced by virus infection. A total of 54 new miRNAs were identified and characterized, six of which, VITIS-MIR17, 18, 19, 20, 21, and 22, were detected only in virus-infected samples. One target of VITIS-MIR18 is the gene coding a non-apical meristem protein (GSVIVT00035370001), a transcription factor in the regulation of plant development and stress responses. Among the virus infection-induced known miRNAs, miRNA168 and miRNA3623 likely regulate grapevine\u27s defense response, miRNA319 and miRNA395 modulate the expression of genes that are involved in nutrient metabolisms while miRNA396 plays a role in the regulation of cell division and cell cycle. The abiotic stress-induced miR169 and mi398 were negatively regulated by virus infection in grapevines. In addition, variety-specific miRNAs were discovered and compiled. The newly discovered miRNAs expand the miRNA profiles in the Vitis species. The characteristics of variety-specific and virus infection-associated miRNAs help understand the biology underlying the development and defense response of grapevines

Microfluidic assays for biofuels research

We are developing next-generation assays for biofuels research using microfluidic technologies to provide significant improvement over conventional platforms in throughput, sensitivity, multiplexing and speed of analysis. To develop these microscale assays we utilize technologies covering a wide spectrum of complexity based on the requirements of the assays. For example, using off-the-shelf components we have developed a microtiter plate-based assay for screening cellulases against heterogeneous substrates. This approach relies on in-situ biomass regeneration in micro-volumes to volumetrically meter biomass (sub-mg loading) and also precisely control the amount of residual IL for screening activities of novel IL-tolerant cellulases. We have also developed more sophisticated platforms for screening of lignocellulolytic enzymes using microfluidic chip for electrophoretic analysis of glycans. These chips are being used to screen genetically-engineered enzymes, assess performance of pretreatment processes, and for discovering cellulase activities in microbial communities. We are also developing high throughput microchips to perform combinatorial DNA assembly for optimization of biofuel synthesis pathways