Sexual stage-induced long noncoding RNAs in the filamentous fungus Fusarium graminearum [I]
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ABSTRACT: Long noncoding RNA (lncRNA) plays important roles in morphological differentiation and development in eukaryotes. In filamentous fungi, however, little is known about lncRNAs and their roles in sexual development. Here we describe sexual stage-induced lncRNAs during the formation of perithecium, the sexual fruiting body of Fusarium graminearum. We identified 547 lncRNAs whose expression were developmental stage-specific; about 40% of them peaked during ascus development, when meiosis occurs. A large fraction of the lncRNAs were found to be antisense to mRNAs, forming 300 sense–antisense pairs. Although small RNAs were produced from these overlapped loci, most of the antisense lncRNAs appeared not to be involved in gene silencing pathways. Rather, the expression of antisense lncRNA and sense mRNA pairs tended to be induced in parallel as the perithecium matured. To identify regulatory components for lncRNA expression, we analyzed mutants defective in the nonsense-mediated decay (NMD) pathway. A subset of lncRNAs was specifically targeted by NMD, suggesting a suppressive role of NMD in lncRNA expression during vegetative growth. This study provides comprehensive resources for studying developmental lncRNA that may be important for laying out the multicellular fruiting body plan.
Project description:Long noncoding RNA (lncRNA) plays important roles in morphological differentiation and development in eukaryotes. In filamentous fungi, however, little is known about lncRNAs and their roles in sexual development. Here we describe sexual stage-induced lncRNAs during the formation of perithecium, the sexual fruiting body of Fusarium graminearum. We identified 547 lncRNAs whose expression were developmental stage-specific; about 40% of them peaked during ascus development, when meiosis occurs. A large fraction of the lncRNAs were found to be antisense to mRNAs, forming 300 sense–antisense pairs. Although small RNAs were produced from these overlapped loci, most of the antisense lncRNAs appeared not to be involved in gene silencing pathways. Rather, the expression of antisense lncRNA and sense mRNA pairs tended to be induced in parallel as the perithecium matured. To identify regulatory components for lncRNA expression, we analyzed mutants defective in the nonsense-mediated decay (NMD) pathway. A subset of lncRNAs was specifically targeted by NMD, suggesting a suppressive role of NMD in lncRNA expression during vegetative growth. This study provides comprehensive resources for studying developmental lncRNA that may be important for laying out the multicellular fruiting body plan.
Project description:LncRNAs represent a major transcriptional output of the human genome, but the function of many of these elements is unknown. For chromatin-localized lncRNAs, identification of genomic binding sites of these lncRNAs provides one opportunity to characterize their function. In this experiment, we have used capture hybridization analysis of RNA targets with high-throughput sequencing (CHART-seq) to identify the binding sites of the lncRNA LINC00899 in HeLa cells. LINC00899 is of interest as its depletion results in mitotic delay, suggesting a role in mitotic progression. This experiment contains 5 replicate batches where each batch contains a sample with antisense capture oligonucleotides (COs) to hybridize to and pull down the lncRNA transcript; an input control for the antisense pulldown; a control sample with sense COs, which should not hybridize to and pull down the lncRNA transcript; and an input control for the sense pulldown. All samples in the same batch were generated at the same time, and each pulldown (antisense or sense) was performed on chromatin obtained from independent cell cultures. All samples were subjected to high-throughput paired-end sequencing across two lanes.
Project description:We systematically identified long noncoding natural antisense transcripts (lncNATs), defined as lncRNAs transcribed from the opposite DNA strand of coding or noncoding genes. We identified in total 37,238 sense-antisense transcript pairs and found 70% mRNAs are associated with antisense transcripts in Arabidopsis. To detect the expression levels of these NAT pairs, we designed an Agilent custom array, ATH NAT array, and analyzed RNA samples from Arabidopsis inflorescences, leaves and roots, with 3 biological replicates each. Expression levels of cis-NAT pairs were investigated in WT inflorescences, leaves and roots with 3 biological replicates.
Project description:We systematically identified long noncoding natural antisense transcripts (lncNATs), defined as lncRNAs transcribed from the opposite DNA strand of coding or noncoding genes. We identified in total 37,238 sense-antisense transcript pairs and found 70% mRNAs are associated with antisense transcripts in Arabidopsis. To detect the expression levels of these NAT pairs, we designed an Agilent custom array, ATH NAT array, and analyzed RNA samples from Arabidopsis inflorescences, leaves and roots, with 3 biological replicates each.
Project description:<p>High throughput RNA Sequencing has revealed that the human genome is widely transcribed. However, the extent of natural antisense transcription, the molecular mechanisms by which natural antisense transcripts (NATs) might affect their cognate sense genes, and the role of NATs in cancer are less well understood. Here, we use strand-specific paired-end RNA sequencing (ssRNASeq) on a cohort of 376 cancer patients covering 9 tissue types to comprehensively characterize the landscape of antisense expression. Our results reveal that greater than 60% of annotated transcripts have measureable antisense expression and the expression of sense and antisense transcript pairs is in general positively correlated. Furthermore, by studying the expression of sense/antisense pairs across tissues we identify lineage-specific, ubiquitous and cancer-specific antisense loci. Our results raise the possibility that NATs participate in the regulation of well-known tumor suppressors and oncogenes. Finally, this study provides a catalogue of cancer related genes with significant antisense transcription (oncoNAT). This resource will allow researchers to investigate the molecular mechanisms of sense/antisense regulation and further advance our understanding of their role in cancer.</p>
Project description:The human malaria parasite Plasmodium falciparum has a complex and multi-stage life cycle that requires extensive immune escape, invasion of human liver and blood cells, and transmission through the female Anopholes mosquito. To date, the regulatory elements orchestrating these critical parasite processes remain largely unknown. However, there is mounting evidence across a broad range of species that intergenic long non-coding RNA (lncRNA) and antisense RNA can regulate chromatin state and gene expression. To pursue such functional roles for lncRNAs in P. falciparum, we performed deep, strand-specific RNA sequencing of fifteen non-polyA-selected blood stage samples, and assembled and characterized the properties of 660 intergenic lncRNAs, 474 antisense RNAs, and 1381 circular RNAs (circRNAs). We further validated the non-canonical splice junctions of seven P. falciparum circRNAs, an emerging class of non-coding RNA with regulatory potential and unexplored functional significance in P. falciparum. Our comprehensive analysis of P. falciparum lncRNAs indicates a functional role for these transcripts; P. falciparum intergenic lncRNAs and antisense RNAs are developmentally regulated in a similar periodic fashion to annotated transcripts, and sense-antisense pair expression is significantly anti-correlated. Notable outliers include intergenic lncRNAs that strongly peak in expression during parasite invasion, such as the telomere-associated lncRNA-TARE family, antisense transcripts that drop in expression during parasite invasion, and a highly correlated, multi-exonic, antisense counterpart to P. falciparum Gametocyte Developmental Protein 1 (PfGDV1). Taken together, our results present over two thousand P. falciparum intergenic lncRNA, antisense, and circRNA candidates and highlight promising P. falciparum lncRNAs for future investigation. We harvested fifteen blood stage samples from two biological replicate time-courses. The first time-course comprised of eleven samples that finely map temporal changes during P. falciparum blood stage development. We harvested samples over 56 hours, at roughly 4-hour time intervals, from a tightly synchronized P. falciparum 3D7 parasite population. As the asexual blood stage is an approximately 48-hour cycle, this time-course allowed us to profile gene expression during RBC rupture and parasite invasion. The second time-course comprised of four samples harvested in synchronous P. falciparum 3D7 parasites approximately four hours before and after the ring to trophozoite and trophozoite to schizont morphological stage transitions, which occur during the blood stage at 24 hours post invasion (hpi) and 36 hpi, respectively.
Project description:Only a minuscule fraction of long non-coding RNAs (lncRNAs) are well characterized. The evolutionary history of lncRNAs can provide insights into their functionality, but comparative analyses have been precluded by our ignorance of lncRNAs in non-model organisms. Here, we use RNA sequencing to identify lncRNAs in eleven tetrapod species and we present the first large-scale evolutionary study of lncRNA repertoires and expression patterns. We identify ~11,000 primate- specific lncRNA families, which show evidence for selective constraint during recent evolution, and ~2,400 highly conserved lncRNAs (including ~400 genes that likely originated more than 300 million years ago). We find that lncRNAs, in particular ancient ones, are generally actively regulated and may predominantly function in embryonic development. lncRNA X-inactivation patterns reveal an extremely female-biased monotreme-specific lncRNA, which may partially compensate X-dosage in this lineage. Most lncRNAs evolve rapidly in terms of sequence and expression levels, but global patterns like tissue specificities are often conserved. We compared expression patterns of homologous lncRNA and protein-coding families across tetrapods to reconstruct an evolutionarily conserved co-expression network. This network, which surprisingly contains many lncRNA hubs, suggests potential functions for lncRNAs in fundamental processes like spermatogenesis or synaptic transmission, but also in more specific mechanisms such as placenta growth suppression through miRNA production. [Batch 1 and 2] To broaden our understanding of lncRNA evolution, we used an extensive RNA-seq dataset to establish lncRNA repertoires and homologous gene families in 11 tetrapod species. We analyzed the poly- adenylated transcriptomes of 8 organs (cortex/whole brain without cerebellum, cerebellum, heart, kidney, liver, placenta, ovary and testis) and 11 species (human, chimpanzee, bonobo, gorilla, orangutan, macaque, mouse, opossum, platypus, chicken and the frog Xenopus tropicalis), which shared a common ancestor ~370 millions of years (MY) ago. Our dataset included 47 strand-specific samples, which allowed us to confirm the orientation of gene predictions and to address the evolution of sense-antisense transcripts. See also GSE43721 (Soumillon et al, Cell Reports, 2013) for three strand-specific samples for mouse brain, liver and testis.
Project description:The human malaria parasite Plasmodium falciparum has a complex and multi-stage life cycle that requires extensive immune escape, invasion of human liver and blood cells, and transmission through the female Anopholes mosquito. To date, the regulatory elements orchestrating these critical parasite processes remain largely unknown. However, there is mounting evidence across a broad range of species that intergenic long non-coding RNA (lncRNA) and antisense RNA can regulate chromatin state and gene expression. To pursue such functional roles for lncRNAs in P. falciparum, we performed deep, strand-specific RNA sequencing of fifteen non-polyA-selected blood stage samples, and assembled and characterized the properties of 660 intergenic lncRNAs, 474 antisense RNAs, and 1381 circular RNAs (circRNAs). We further validated the non-canonical splice junctions of seven P. falciparum circRNAs, an emerging class of non-coding RNA with regulatory potential and unexplored functional significance in P. falciparum. Our comprehensive analysis of P. falciparum lncRNAs indicates a functional role for these transcripts; P. falciparum intergenic lncRNAs and antisense RNAs are developmentally regulated in a similar periodic fashion to annotated transcripts, and sense-antisense pair expression is significantly anti-correlated. Notable outliers include intergenic lncRNAs that strongly peak in expression during parasite invasion, such as the telomere-associated lncRNA-TARE family, antisense transcripts that drop in expression during parasite invasion, and a highly correlated, multi-exonic, antisense counterpart to P. falciparum Gametocyte Developmental Protein 1 (PfGDV1). Taken together, our results present over two thousand P. falciparum intergenic lncRNA, antisense, and circRNA candidates and highlight promising P. falciparum lncRNAs for future investigation.
Project description:We characterized the expression patterns of sense-antisense transcripts, based on available cDNA sequences, in colon (colorectal) cancer tissues and in normal tissues surrounding the cancer tissues. Although expression balances (ratios) of most of sense and antisense transcript pairs did not change between patients or between normal and cancer tissues, we found 68 sense-antisense transcripts whose expression balances were altered specifically in colon cancer tissues. We conducted DNA microarray analyses by using the same set of probes designed for 2621 sense-antisense pairs to detect transcripts expressed in colon cancer tissues. These probes comprise 2358 pairs for the detection of protein-coding transcripts only, 250 pairs for the detection of protein-coding transcripts paired with non-protein-coding transcripts, and 13 pairs for the detection of non-protein-coding transcripts only.
Project description:We characterized the expression patterns of sense-antisense transcripts, based on available cDNA sequences, in colon (colorectal) cancer tissues and in normal tissues surrounding the cancer tissues. Although expression balances (ratios) of most of sense and antisense transcript pairs did not change between patients or between normal and cancer tissues, we found 68 sense-antisense transcripts whose expression balances were altered specifically in colon cancer tissues.