Digital Gene Expression Analysis Based on Integrated De Novo Transcriptome Assembly of Sweet Potato [Ipomoea batatas (L.) Lam.]
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ABSTRACT: More than 3.5 million raw DGE tags were obtained in each library. The clean tags in each sample ranged from 3.35 to 3.63 million, and the distinct clean tags ranged from 93,593 to 139,389. The 21 bp DGE clean tags were mapped to sweet potato transcripts. Then, we compared 7 libraries pair-wisely so that 21 pairs of comparisons were implemented. Among these comparisons, we found that 4,721 to 12,151 transcripts had significant changes in expression, and the average number was 9,657. We also observed a large number of specifically expressed transcripts between each two libraries. The expression profiles of those genes involved in root development and carbohydrates accumulation were characterized. Moreover, other genes of interest, such as potentially abiotic stress tolerance and insect resistance, were also characterized.
Project description:More than 3.5 million raw DGE tags were obtained in each library. The clean tags in each sample ranged from 3.35 to 3.63 million, and the distinct clean tags ranged from 93,593 to 139,389. The 21 bp DGE clean tags were mapped to sweet potato transcripts. Then, we compared 7 libraries pair-wisely so that 21 pairs of comparisons were implemented. Among these comparisons, we found that 4,721 to 12,151 transcripts had significant changes in expression, and the average number was 9,657. We also observed a large number of specifically expressed transcripts between each two libraries. The expression profiles of those genes involved in root development and carbohydrates accumulation were characterized. Moreover, other genes of interest, such as potentially abiotic stress tolerance and insect resistance, were also characterized. 7 samples are examined: young leaves, mature leaves, stems, fibrous roots, initial tuberous roots, expanding tuberous roots and harvest tuberous roots.
Project description:Analysis of the different gene expression profiles of natural and resynthesized Brassica polyploids with Illumina deep sequencing technology could help to improve our knowledge of polyploid genome evolution. We obtained approximately 6 million sequence tags per sample,and 6018254, 5930726, 6022170, 5950123, 5991210, 5798939, 5823113, 5772449,5858527 and 5657697 clean tags were obtained in libraries of B. rapa, B. oleracea, B. napus-F1, B. napus-F2, B. napus-F3, B. napus-F4, natural B. napus, B. nigra, B. juncea and B. carinata, respectively.16574, 15970, 22059, 18155, 16479, 18196, 17448, 13867, 19424 and 16645 genes of B. rapa genome were unambigously mapped by sequence tags of these ten DGE libraries, respectively. Differentially expressed genes during polyploidization were broadly discovered by comparing the tetraploids with their progenitors.
Project description:This experiment contains Phytophthora sojae samples and RNA-seq data from experiment E-GEOD-29561 (https://www.ebi.ac.uk/arrayexpress/experiments/E-GEOD-29651/) to understand gene expression during the P. sojae life cycle. The transcriptome of the oomycete plant pathogen Phytophthora sojae was profiled at 5 different developmental stages: mycelia (MY), zoosporangia (SP), zoospores (ZO), cysts (CY) and germinating cysts (GC); based on a 3'-tag digital gene expression (DGE) protocol. More than 90 million clean sequence tags were generated and compared to the P. sojae genome and its 19,027 predicted genes. A total of 14,969 genes were detected, of which 10,044 were deemed reliable because they mapped to unambiguous tags. A web-based server named the Phytophthora Transcriptional Database (PTD) has been established.
Project description:Analysis of the different gene expression profiles of natural and resynthesized Brassica polyploids with Illumina deep sequencing technology could help to improve our knowledge of polyploid genome evolution. We obtained approximately 6 million sequence tags per sample,and 6018254, 5930726, 6022170, 5950123, 5991210, 5798939, 5823113, 5772449,5858527 and 5657697 clean tags were obtained in libraries of B. rapa, B. oleracea, B. napus-F1, B. napus-F2, B. napus-F3, B. napus-F4, natural B. napus, B. nigra, B. juncea and B. carinata, respectively.16574, 15970, 22059, 18155, 16479, 18196, 17448, 13867, 19424 and 16645 genes of B. rapa genome were unambigously mapped by sequence tags of these ten DGE libraries, respectively. Differentially expressed genes during polyploidization were broadly discovered by comparing the tetraploids with their progenitors. mRNA obtained from young leaves of 28-days-old seedlings were compared during polyploidization.
Project description:Background and aimsThe tuberization mechanism of sweet potato (Ipomoea batatas) has long been studied using various approaches. Morphological data have revealed that the tuberizing events result from the activation of the cambium, followed by cell proliferation. However, uncertainties still remain regarding the regulators participating in this signal-transduction pathway. An attempt was made to characterize the role of one MADS-box transcription factor, which was preferentially expressed in sweet potato roots at the early tuberization stage.MethodsA differential expression level of IbMADS1 (Ipomoea batatas MADS-box 1) was detected temporally and spatially in sweet potato tissues. IbMADS1 responses to tuberization-related hormones were assessed. In order to identify the evolutionary significance, the expression pattern of IbMADS1 was surveyed in two tuber-deficient Ipomoea relatives, I. leucantha and I. trifida, and compared with sweet potato. In functional analyses, potato (Solanum tuberosum) was employed as a heterologous model. The resulting tuber morphogenesis was examined anatomically in order to address the physiological function of IbMADS1, which should act similarly in sweet potato.Key resultsIbMADS1 was preferentially expressed as tuberous root development proceeded. Its expression was inducible by tuberization-related hormones, such as jasmonic acid and cytokinins. In situ hybridization data showed that IbMADS1 transcripts were specifically distributed around immature meristematic cells within the stele and lateral root primordia. Inter-species examination indicated that IbMADS1 expression was relatively active in sweet potato roots, but undetectable in tuber-deficient Ipomoea species. IbMADS1-transformed potatoes exhibited tuber morphogenesis in the fibrous roots. The partial swellings along fibrous roots were mainly due to anomalous proliferation and differentiation in the xylem.ConclusionsBased on this study, it is proposed that IbMADS1 is an important integrator at the initiation of tuberization. As a result, the initiation and development of tuberous roots seems to be well regulated by a network involving a MADS-box gene in which such hormones as jasmonic acid and cytokinins may act as trigger factors.
Project description:Purpose: the technology of Solexa/Illumina (RNA-seq) is an attractive alternative to the transcriptome sequencing. The goals of this study are to investigate transcriptional changes in replanted R. glutinosa leaves and identify genes responding to the disease. Methods:Totally 6.01and 6.15 million raw tags were measured from leaves of the first year planted (L1) and the second year replanted R. glutinosa (L2) at the tuberous root expansion stage, respectively. mRNA profiles of leaves of the first year planted (L1) and the second year replanted R. glutinosa (L2) at the tuberous root expansion stage, were generated by deep sequencing (Illumina HiSeq™ 2000 system). qRT–PCR validation was performed using SYBR Green assays. Results: we obtained a total of 6.01 and 6.15 million total tags including 377,200 and 361,659 distinct tags from the L1 and L2 samples, respectively. Removal of low quality tags, 161,298 and 149,290 distinct clean tags were remained.With reference to the 94,544 non-redundant consensus sequences defined by the RNA-seq transcriptomic procedure, 60,574 genes had the diagnostic CATG site, which were taken as reference distinct sequences for DGE analysis. 47,458 of the L1 tag library and 42,247 of the L2 tag library were perfectly matched the reference sequences. we screened differentially expressed genes in the L1 and L2 libraries by digital gene expression (DGE) technique. Finally, a set of 1,954 genes may be in differential expression of L2. By bioinformatics and qRT-PCR, the 117 most strongly differentially expressed ones were considered to be prime candidates for responsible for replanting disease. Conclusions: The study provides an important resource for further investigating the cause of replanting disease and developing the methods to control or subtract its injury.
Project description:Using Illumina’s digital gene expression (DGE) system, we investigated the transcriptional response to TLX overexpression in beta cells. Finally, an average of 13,791,918 and 12,476,623 reads of high quality clean tags were obtained from control and TLX-overexpressing beta cells, respectively. Results reveals that overexpression of TLX resulted in suppression of 176 genes by ≥50%, and also results in ≥2-fold upregulation of 49 genes.
Project description:The Solexa/Illumina’s digital gene expression (DGE) system was used to gain insight into the broad range of transcriptional responses during the vegetative growth, sclerotial development, myceliogenic germination, carpogenic germination, apothecium formation (stipe) and infection of Sclerotinia sclerotiorum. We obtained a sequencing depth of approximately 3.3 million clean tags per cDNA library. Tag mapping indicated that these six cDNA libraries in total represented more than 66.7% of all of the genes presented in the predicted transcript databases of the Broad Institute. Thouthands of differentially expressed genes were indentified during the various developmental stages compared to the vegetative growth stage. Our results could increase and deepen the understanding of the vegetative and reproductive development as well as the infection of S. sclerotiorum
Project description:In the present study, RNA-seq technique was used to compare the expression profiles of lncRNAs from goat endometrium samples at gestational day 5 (pre-receptive endometrium, PE) and day 15 (receptive endometrium, RE). This yielded 18 gigabases (Gb) of sequence, representing approximately seven times the size of the genome (2.66 Gb). A total of 120 million raw reads were produced from the Illumina HiSeq 2500 platform. After discarding adaptor sequences and low-quality sequences, 90 to 97 million clear reads per sample were obtained, and the percentage of clean reads among raw tags in each library ranged from 75.79–81.03 %. A total of 668 lncRNAs were found to differ significantly in terms of expressional levels (P< 0.05) between the PE and RE libraries,98.35% of the DELs were mapped to “u” (Unknown, intergenic transcript).Our results included 76,844 lncRNAs that corresponded to 42,933 protein-coding genes within a range of 1-100 kb. It deserved to note that 783 target genes of the 200 DELs that were annotated to 153 GO terms meeting our designated criteria of P-values< 0.05, KEGG pathway annotation showed 242 target genes of the DELs were annotated for 146 KEGG pathways.