Project description:The Babaco Mosaic Virus (BabMV) is a Potexvirus that affects babaco (Vasconcellea heilbornii) and papaya (Carica papaya) plants. To understand the impact of the virus on the plant, we performed a genome-wide transcriptome analysis of the response of young leaves of 3-4 months old papaya plants at 2, 10, 15- and 30-days post infection (dpi) in comparison to uninfected controls. Results showed that in mock-infected plants and virus-infected plants at 2 and 10dpi more than 90% of the reads mapped to the papaya genome. In contrast, at 15 and 30 dpi only 31% mapped to the papaya genome in BabMV infected leaves, while the remaining 69% of the reads aligned to the virus genome, demonstrating a high viral load. A total of 1585 papaya genes were differentially expressed between mock and BabMV inoculated leaves, among which cell wall biogenesis, redox signaling, and ribosome Gene Ontology terms were overrepresented, interestingly, the virus induced specific responses at different time points. Sugar metabolism and cell wall modification including lignin accumulation genes were affected at 15 dpi. At 30 days post-infection, the virus primarily induced ROS production, possibly through the activation of cytochrome P450 enzymes. This led to the upregulation of genes associated with ROS scavenging and of transcription factors (TFs) belonging to the WRKY and AP2/ERF families, which play crucial roles in activating the plant's defense mechanisms against viral pathogens. This research enhances our understanding of BabMV infections, facilitating the development of effective disease control measures.
Project description:Small RNAs (21-24 nt) are pivotal regulators of gene expression that guide both transcriptional and post-transcriptional silencing mechanisms in diverse eukaryotes, including most if not all plants. MicroRNAs (miRNAs) and short interfering RNAs (siRNAs) are the two major types, both of which have a demonstrated and important role in plant development, stress responses and pathogen resistance. In this work, we used a deep sequencing approach (Sequencing-By-Synthesis, or SBS) to develop sequence resources of small RNAs from different Carica papaya tissues (including leaves and flowers). The high depth of the resulting datasets enabled us to examine in detail critical small RNA features, such as size distribution, tissue-specific regulation and sequence conservation between different organs in this species. We also developed database resources and a dedicated website (http://smallrna.udel.edu/) with computational tools for allowing other users to identify new miRNAs or siRNAs involved in specific regulatory pathways, verify the degree of conservation of these sequences in other plant species and map small RNAs on genes or larger regions of the maize genome under study. Small RNA libraries were derived from leaves, virus-infected leaves and female flowers of Carica papaya. Total RNA was isolated using the TriReagent (Molecular Research Center) and submitted to Illumina (Hayward, CA, http://www.illumina.com) for small RNA library construction using approaches described in (Lu et al., 2007) with minor modifications. The small RNA libraries were sequenced with the Sequencing-By-Synthesis (SBS) technology by Illumina. PERL scripts were designed to remove the adapter sequences and determine the abundance of each distinct small RNA. We thank Ray Ming and Qingyi Yu for providing the plant material, as well as Kan Nobuta and Gayathri Mahalingam for assistance with the computational methods.
Project description:Triple negative breast cancer is an aggressive phenotypic breast cancer characterized by ER negative, PR negative and Her2 negative immunohistochemistry status. We embarked on a study to explore the transcriptome of Kenyan TNBC patients and identify potential biomarkers specific to Kenyan population. The transcriptome sequencing of tumors from Kenyan TNBC patients and comparisons with African American and Caucasian TNBC transcriptomes revealed several interesting targets and dysregulated pathways.
Project description:Background: Papaya (Carica papaya L.) is a commercially important crop that produces climacteric fruits with a soft and sweet pulp that contain a wide range of health promoting phytochemicals. Despite its importance, little is known about transcriptional modifications during fruit ripening and its control. In this study we report the analysis of ripe papaya transcriptome by using a cross-species (XSpecies) microarray technique based on the phylogenetic proximity between papaya and Arabidopsis thaliana. Results: Papaya transcriptome analyses resulted in the identification of 414 ripening-related genes and some of them had their expression validated by qPCR. The transcription profile was then compared with that from ripening tomato and grape. Overall, the transcriptomics analysis revealed many similarities between ripening in papaya and tomato especially with respect to primary metabolism, regulation of transcription, biotic and abiotic stress and cell wall metabolism. XSpecies microarray data indicate that transcription factors (TFs) of the MADS-box, NAC and AP2/ERF gene families are involved in the control of papaya ripening and reveal that cell wall-related gene expression in papaya showed similarities to the expression profiles seen in A. thaliana during hypocotyl development. Conclusion: The cross-species array experiment was successful in identifying ripening-related genes in papaya. The data indicated common and diverse elements of transcription control between fruit bearing taxa and has also indicated a possible distinct co-evolutionary mechanism for papaya cell wall disassembling system. The present study represents new topics for future researches that would help complement the structural genomic data provided by the papaya genome, since there is no gene-chip available for this plant organism. Papaya ripe transcriptome was analysed using mRNA extracted from unripe and ripe fruit from 2 replicates. After microarray hybridization in ATH1-121501 chip, data were normalized against data generated by papaya DNA hybridization in another ATH1-121501 chip and analysed using perl algorithms (masks).
Project description:Next-Generation-Sequencing (NGS) technologies have led to important improvement in the detection of new or unrecognized infective agents, related to infectious diseases. In this context, NGS high-throughput technology can be used to achieve a comprehensive and unbiased sequencing of the nucleic acids present in a clinical sample (i.e. tissues). Metagenomic shotgun sequencing has emerged as powerful high-throughput approaches to analyze and survey microbial composition in the field of infectious diseases. By directly sequencing millions of nucleic acid molecules in a sample and matching the sequences to those available in databases, pathogens of an infectious disease can be inferred. Despite the large amount of metagenomic shotgun data produced, there is a lack of a comprehensive and easy-use pipeline for data analysis that avoid annoying and complicated bioinformatics steps. Here we present HOME-BIO, a modular and exhaustive pipeline for analysis of biological entity estimation, specific designed for shotgun sequenced clinical samples. HOME-BIO analysis provides comprehensive taxonomy classification by querying different source database and carry out main steps in metagenomic investigation. HOME-BIO is a powerful tool in the hand of biologist without computational experience, which are focused on metagenomic analysis. Its easy-to-use intrinsic characteristic allows users to simply import raw sequenced reads file and obtain taxonomy profile of their samples.
Project description:Human mucosal surfaces contain a wide range of microorganisms. The biological effects of these organisms are largely unknown. Large-scale metagenomic sequencing is emerging as a method to identify novel microbes. Unexpectedly, we identified DNA sequences homologous to virus ATCV-1, an algal virus not previously known to infect humans, in oropharyngeal samples obtained from healthy adults. The presence of ATCV-1 was associated with a modest but measurable decrease in cognitive functioning. A relationship between ATCV-1 and cognitive functioning was confirmed in a mouse model, which also indicated that exposure to ATCV-1 resulted in changes in gene expression within the brain. Our study indicates that viruses in the environment not thought to infect humans can have biological effects.