Project description:High mitochondrial DNA (mtDNA) copy numbers are essential for oogenesis and embryogenesis and correlate with fertility of oocytes and viability of embryos. To understand the pathology and mechanisms associated with low mtDNA copy numbers, we knocked down mitochondrial transcription factor A (Tfam), a regulator of mtDNA replication, during early zebrafish development. Reduction of Tfam using a splice-modifying morpholino (MO) resulted in a 42%±4% decrease in mtDNA copy number in embryos at 4 days post fertilization (4 dpf). Morphant embryos displayed abnormal development of the eye, brain, heart and muscle, as well as a 50%±11% decrease in ATP production. Transcriptome analysis revealed a decrease in protein-encoding transcripts from the heavy strand of the mtDNA. In addition, various RNA translation pathways were increased, indicating an upregulation of nuclear and mitochondria-related translation. The developmental defects observed were supported by a decreased expression of pathways related to eye development and haematopoiesis. The increase in mRNA translation might serve as a compensation mechanism, but appears insufficient during prolonged periods of mtDNA depletion, highlighting the importance of high mtDNA copy numbers for early development in zebrafish.
Project description:Most proteogenomic approaches for mapping single amino acid polymorphisms (SAPs) require construction of a sample-specific database containing protein variants predicted from the next-generation sequencing (NGS) data. We present a new strategy for direct SAP detection without relying on NGS data. Among the 348 putative SAP peptides identified in an industrial yeast strain, 85.6% of SAP sites were validated by genomic sequencing.
Project description:The mucosa is an ideal route for vaccination against pathogen infection, but the effective adjuvant capable of overcoming the tolerogenic dendritic cell (DC) environment is unavailable. We characterized type 2 conventional DCs and lysozyme-expressing monocyte-derived DCs (LysoDCs) of Peyer’s patches to identify the vaccination target cells through single-cell RNA sequencing. Based on functional analysis of the data, we suggest that C5aR+ LysoDCs and Co1 peptide, a C5aR ligand, as a target cell and an adjuvant, respectively, for mucosal vaccination. Co1-mediated stimulation of C5aR+ LysoDCs increased the level of reactive oxygen species, leading to CCL3-mediated chemotaxis and exogenous antigen cross-presentation, which elicited an antigen-specific CD8+ T cell response. In a SARS-CoV-2 vaccine model, Co1 peptide increased the frequency of antigen-specific polyfunctional CD8+ T cells in systemic as well as mucosal compartments. Collectively, LysoDC activation by Co1 peptide potentiates vaccination efficiency by constructing an immunostimulatory environment in the mucosal immune inductive site.
Project description:This study sought to evaluate the effects of dietary MeHg exposure on adult female yellow perch (Perca flavescens) and zebrafish (Danio rerio) reproduction by relating controlled exposures with subsequent reproductive effects. Yellow perch were used in the study for their socioeconomic and ecological importance within the Great Lakes basin, and the use of zebrafish allowed for a detailed analysis of the molecular effects of MeHg. MeHg exposures at environmentally relevant levels were done in zebrafish for a full life cycle, mimicking a realistic exposure scenario, and in adult yellow perch for twenty weeks, capturing early seasonal ovarian development. In zebrafish, several genes involved in reproductive processes were shown to be dysregulated by RNA-seq and QPCR, but no significant phenotypic or physiological changes were observed with ovarian staging, fecundity, or embryo mortality. Yellow perch did not appear to be affected by MeHg, either at a molecular level, as assessed by QPCR of eight genes in the pituitary, liver, and ovary tissue, or a physiological level, as seen with ovarian somatic index, circulating estradiol, and ovarian staging. Lack of impact in yellow perch limits the usefulness of zebrafish as a model and suggests that the reproductive sensitivity to environmentally relevant levels of MeHg differs between yellow perch and zebrafish.
2018-01-01 | GSE73615 | GEO
Project description:Humic-acid-driven escape from eye parasites
Project description:The Root-lesion nematode (RLN) Pratylenchus coffeae is a major ramie pest causing severe fiber yield loss annual in China. The response mechanism of ramie to RLN-infection is poorly understood. Two RLN-infected plants (Inf1 and Inf2) and two control plants (CO1 and CO2) were individually used to sequence by Illumina pair-end sequencing. About 56.3, 51.7, 43.4 and 45.0 million sequencing reads were generated from the libraries of CO1, CO2, Inf1 and Inf2, respectively. De novo assembly for these 196 million reads yielded 50,486 unigenes with an average length of 853.3 bp. Based on sequence similarity search with known proteins, a total of 24,820 (49.2%) genes were annotated for their function. Comparison of gene expression level between CO and Inf ramie based on the normalized value of read counts per kilobase of exon model per million reads (RPKM) revealed that there were 777 differentially expressed genes (DEGs). Further, these functional category of DEGs were classified by assigning them to gene ontology (GO) and clusters of orthologous group (COG). Pathway enrichment analysis showed that three pathways (Phenylalanine metabolism, Carotenoid biosynthesis and Phenylpropanoid biosynthesis) were severely influenced by RLN-infection. The genome-wide expression profiling of ramie responding to RLN-infection was first characterized. A series of candidate genes and pathways that may contribute to defense response against RLN in ramie will be helpful for further improving the resistance to RLN-infection. A total of four samples, two replicates of control plant (CO1 and CO2) and two replicates of RLN-infected plants (Inf1 and Inf2) were used for RNA-seq.
Project description:We conducted microarray experiments by comparing constitutive constructs with appropriate controls, followed by the identification of downstream targets of Pro35S:CO1 Four samples of mature leaf tissues were collected from four independent lines of 35S:CO1 and pBI101. RNA was extracted from tissues and hybridized on Affymetrix Genechip Poplar Genome Array.
Project description:Cadmium (Cd)-contamination in soil has been becoming a major environmental problem in China. Ramie, a fiber crop, was frequently proposed to be used as the crop for phytoremediation of Cd-contaminated farmlands. However, high level Cd accumulation can cause a great inhibition of growth in ramie. To understand the potential mechanism for this phenomenon, the ramie genes involved in the Cd stress response were identified using Illumina pair-end sequencing in two Cd-stressed plants (CdS1 and CdS2) and two control plants (CO1 and CO2) in this study. Approximately 48.7, 51.6, 41.2, and 47.1 million clean sequencing reads generated from the libraries of CO1, CO2, CdS1, and CdS2, respectively, were De novo assembled to yield 56,932 non-redundant unigenes. A total of 26,686 (46.9%) genes were annotated for their function. Comparison of gene expression levels between CO and CdS ramie revealed 155 differentially expressed genes (DEGs). Sixteen DEGs was further confirmed their expression difference by real-time quantitative PCR (qRT-PCR). Among these 16 DEGs, 2 genes encoding GA2-oxidase which is a major enzyme for deactivating bioactive gibberellins (GAs) were found with a markedly up-regulated expression, which is possibly responsible for the growth inhibition of Cd-stressed ramie. Pathway enrichment analysis revealed that a pathway (Cutin, suberine and wax biosynthesis) was markedly enriched by DEGs. The discovery of these Cd stress-responsive genes and pathways will be helpful for further understanding the mechanism of Cd-stressed response and improving the ability of Cd stress tolerance in ramie. A total of four samples, two replicates of control plants (CO1 and CO2) and two replicates of cadmium-stressed plants (CdS1 and CdS2) were used for RNA-seq.
Project description:Regulation of replication and expression of mitochondrial DNA (mtDNA) is essential for cellular energy conversion via oxidative phosphorylation. The mitochondrial transcription elongation factor (TEFM) has been proposed to regulate the switch between transcription termination for replication primer formation and processive, near-genome length transcription for mtDNA gene expression. Here, we report that Tefm is essential for mouse embryogenesis and that levels of promoter-distal mitochondrial transcripts are drastically reduced in conditional Tefm-knockout hearts. In contrast, the promoter-proximal transcripts are much increased in Tefm knockouts, but they mostly terminate before the region where the switch from transcription to replication occurs, and consequently de novo mtDNA replication is profoundly reduced. Unexpectedly, deep sequencing of RNA from Tefm knockouts revealed accumulation of unprocessed transcripts in addition to defective transcription elongation. Furthermore, a proximity labelling (BioID) assay showed that TEFM interacts with multiple RNA processing factors. Our data demonstrate that TEFM acts as a general transcription elongation factor, necessary for both gene transcription and replication primer formation, and loss of TEFM affects RNA processing in mammalian mitochondria.
Project description:Altered mitochondrial function in prostate cancer was characterized using paired malignant/non-malignant (benign) tissue samples. Mitochondrial DNA heteroplasmies (mtDNA-NGS) and mitochondria associated gene transcript levels (RNAseq-NGS) were analyzed and correlated to mitochondrial respiration (high-resolution respirometry), to each other and to the tumor stage and grade.