scholarly journals Full-length transcriptome reconstruction reveals a large diversity of RNA and protein isoforms in rat hippocampus

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Xi Wang ◽  
Xintian You ◽  
Julian D. Langer ◽  
Jingyi Hou ◽  
Fiona Rupprecht ◽  
...  

Abstract Gene annotation is a critical resource in genomics research. Many computational approaches have been developed to assemble transcriptomes based on high-throughput short-read sequencing, however, only with limited accuracy. Here, we combine next-generation and third-generation sequencing to reconstruct a full-length transcriptome in the rat hippocampus, which is further validated using independent 5´ and 3´-end profiling approaches. In total, we detect 28,268 full-length transcripts (FLTs), covering 6,380 RefSeq genes and 849 unannotated loci. Based on these FLTs, we discover co-occurring alternative RNA processing events. Integrating with polysome profiling and ribosome footprinting data, we predict isoform-specific translational status and reconstruct an open reading frame (ORF)-eome. Notably, a high proportion of the predicted ORFs are validated by mass spectrometry-based proteomics. Moreover, we identify isoforms with subcellular localization pattern in neurons. Collectively, our data advance our knowledge of RNA and protein isoform diversity in the rat brain and provide a rich resource for functional studies.

2021 ◽  
Vol 7 (15) ◽  
pp. eabe0317
Author(s):  
Yusuke Oguchi ◽  
Yuka Ozaki ◽  
Mahmoud N. Abdelmoez ◽  
Hirofumi Shintaku

Alternative mRNA isoforms play a key role in generating diverse protein isoforms. To dissect isoform usage in the subcellular compartments of single cells, we introduced an novel approach, nanopore sequencing coupled with single-cell integrated nuclear and cytoplasmic RNA sequencing, that couples microfluidic fractionation, which separates cytoplasmic RNA from nuclear RNA, with full-length complementary DNA (cDNA) sequencing using a nanopore sequencer. Leveraging full-length cDNA reads, we found that the nuclear transcripts are notably more diverse than cytoplasmic transcripts. Our findings also indicated that transcriptional noise emanating from the nucleus is regulated across the nuclear membrane and then either attenuated or amplified in the cytoplasm depending on the function involved. Overall, our results provide the landscape that shows how the transcriptional noise arising from the nucleus propagates to the cytoplasm.


2007 ◽  
Vol 88 (2) ◽  
pp. 621-630 ◽  
Author(s):  
S. Maan ◽  
N. S. Maan ◽  
A. R. Samuel ◽  
S. Rao ◽  
H. Attoui ◽  
...  

The outer capsid protein VP2 of Bluetongue virus (BTV) is a target for the protective immune response generated by the mammalian host. VP2 contains the majority of epitopes that are recognized by neutralizing antibodies and is therefore also the primary determinant of BTV serotype. Full-length cDNA copies of genome segment 2 (Seg-2, which encodes VP2) from the reference strains of each of the 24 BTV serotypes were synthesized, cloned and sequenced. This represents the first complete set of full-length BTV VP2 genes (from the 24 serotypes) that has been analysed. Each Seg-2 has a single open reading frame, with short inverted repeats adjacent to conserved terminal hexanucleotide sequences. These data demonstrated overall inter-serotype variations in Seg-2 of 29 % (BTV-8 and BTV-18) to 59 % (BTV-16 and BTV-22), while the deduced amino acid sequence of VP2 varied from 22.4 % (BTV-4 and BTV-20) to 73 % (BTV-6 and BTV-22). Ten distinct Seg-2 lineages (nucleotypes) were detected, with greatest sequence similarities between those serotypes that had previously been reported as serologically ‘related’. Fewer similarities were observed between different serotypes in regions of VP2 that have been reported as antigenically important, suggesting that they may play a role in the neutralizing antibody response. The data presented form an initial basis for BTV serotype identification by sequence analyses and comparison of Seg-2, and for development of molecular diagnostic assays for individual BTV serotypes (by RT-PCR).


Blood ◽  
1998 ◽  
Vol 91 (7) ◽  
pp. 2369-2380 ◽  
Author(s):  
Diana Metes ◽  
Linda K. Ernst ◽  
William H. Chambers ◽  
Andrei Sulica ◽  
Ronald B. Herberman ◽  
...  

Human natural killer (NK) cells were thought to express only FcγRIIIA (CD16), but recent reports have indicated that NK cells also express a second type of FcγR, ie, FcγRII (CD32). We have isolated, cloned, and sequenced full-length cDNAs of FcγRII from NK cells derived from several normal individuals that may represent four different products of the FcγRIIC gene. One transcript (IIc1) is identical with the already described FcγRIIc form. The other three (IIc2-IIc4) appear to represent unique, alternatively spliced products of the same gene, and include a possible soluble form. Analyses of the full-length clones have revealed an allelic polymorphism in the first extracellular exon, resulting in either a functional open reading frame isoform or a null allele. Stable transfection experiments enabled us to determine a unique binding pattern of anti-CD32 monoclonal antibodies to FcγRIIc. Further analyses of NK-cell preparations revealed heterogeneity in CD32 expression, ranging from donors lacking CD32 expression to donors expressing high levels of CD32 that were capable of triggering cytotoxicity. Differences in expression were correlated with the presence or absence of null alleles. These data show that certain individuals express high levels of functional FcγRIIc isoforms on their NK cells.


2021 ◽  
Vol 12 ◽  
Author(s):  
Fiza Liaquat ◽  
Muhammad Farooq Hussain Munis ◽  
Samiah Arif ◽  
Urooj Haroon ◽  
Jianxin Shi ◽  
...  

Schima superba (Theaceae) is a subtropical evergreen tree and is used widely for forest firebreaks and gardening. It is a plant that tolerates salt and typically accumulates elevated amounts of manganese in the leaves. With large ecological amplitude, this tree species grows quickly. Due to its substantial biomass, it has a great potential for soil remediation. To evaluate the thorough framework of the mRNA, we employed PacBio sequencing technology for the first time to generate S. Superba transcriptome. In this analysis, overall, 511,759 full length non-chimeric reads were acquired, and 163,834 high-quality full-length reads were obtained. Overall, 93,362 open reading frames were obtained, of which 78,255 were complete. In gene annotation analyses, the Kyoto Encyclopedia of Genes and Genomes (KEGG), Clusters of Orthologous Genes (COG), Gene Ontology (GO), and Non-Redundant (Nr) databases were allocated 91,082, 71,839, 38,914, and 38,376 transcripts, respectively. To identify long non-coding RNAs (lncRNAs), we utilized four computational methods associated with protein families (Pfam), Cooperative Data Classification (CPC), Coding Assessing Potential Tool (CPAT), and Coding Non-Coding Index (CNCI) databases and observed 8,551, 9,174, 20,720, and 18,669 lncRNAs, respectively. Moreover, nine genes were randomly selected for the expression analysis, which showed the highest expression of Gene 6 (Na_Ca_ex gene), and CAX (CAX-interacting protein 4) was higher in manganese (Mn)-treated group. This work provided significant number of full-length transcripts and refined the annotation of the reference genome, which will ease advanced genetic analyses of S. superba.


2019 ◽  
Author(s):  
Cornelia Fritsch ◽  
F. Javier Bernardo-Garcia ◽  
Tim-Henning Humberg ◽  
Sara Miellet ◽  
Silvia Almeida ◽  
...  

ABSTRACTDevelopment of eye tissue is initiated by a conserved set of transcripton factors termed retinal determination network (RDN). In the fruit fly Drosophila melanogaster, the zinc-finger transcription factor Glass acts directly downstream of the RDN to control idendity of photoreceptor as well as non-photoreceptors cells. Tight control of spatial and temporal gene expression is a critical feature during development, cell-fate determination as well as maintainance of differentiated tissues. The molecular mechanisms that control expression of glass, however remain largely unknown. We here identify complex regulatory mechanisms controlling expression of the glass locus. All information to recapitulate glass expression are contained in a compact 5.2 kb cis-acting genomic element by combining different cell-type specific and general enhancers with repressor elements. Moreover, the immature RNA of the locus contains an alterantive small open reading frame (smORF) upstream of the actual glass translation start, resulting in a small peptide instead of the three possible glass protein isoforms. CRISPR/Cas9-based mutagenesis shows that the smORF is not required for the formation of functioning photoreceptors, but to attenuate effects of glass misexpression. Furthermore, editing the genome to generate glass loci eliminating either one or two isoforms shows that only one of the three proteins is critical for formation of functioning photoreceptors, while removing the two other isoforms did not cause defects in developmental or photoreceptor function. Our results show that eye development and function is surprisingly robust and appears buffered to targeted manipulations of critical features of the glass transcript, suggesting a strong selection pressure to allow the formation of a functioning eye.


2019 ◽  
Author(s):  
Anne Deslattes Mays ◽  
Marcel O. Schmidt ◽  
Garrett T. Graham ◽  
Elizabeth Tseng ◽  
Primo Baybayan ◽  
...  

AbstractHematopoietic cells are continuously replenished from progenitor cells that reside in the bone marrow. To evaluate molecular changes during this process, we analyzed the transcriptomes of freshly harvested human bone marrow progenitor (lineage-negative) and differentiated (lineage-positive) cells by single molecule, real time (SMRT) full length RNA sequencing. This analysis revealed a ∼5-fold higher number of transcript isoforms than previously detected and showed a distinct composition of individual transcript isoforms characteristic for bone marrow subpopulations. A detailed analysis of mRNA isoforms transcribed from the ANXA1 and EEF1A1 loci confirmed their distinct composition. The expression of proteins predicted from the transcriptome analysis was validated by mass spectrometry and validated previously unknown protein isoforms predicted e.g. for EEF1A1. These protein isoforms distinguished the lineage negative cell population from the lineage positive cell population. Finally, transcript isoforms expressed from paralogous gene loci (e.g. CFD, GATA2, HLA-A, B & C) also distinguished cell subpopulations but were only detectable by full length RNA sequencing. Thus, qualitatively distinct transcript isoforms from individual genomic loci separate bone marrow cell subpopulations indicating complex transcriptional regulation and protein isoform generation during hematopoiesis.


1999 ◽  
Vol 19 (1) ◽  
pp. 873-881 ◽  
Author(s):  
O. N. Danilevskaya ◽  
K. L. Traverse ◽  
N. C. Hogan ◽  
P. G. DeBaryshe ◽  
M. L. Pardue

ABSTRACT The transposable elements HeT-A and TARTconstitute the telomeres of Drosophila chromosomes. Both are non-long terminal repeat (LTR) retrotransposons, sharing the remarkable property of transposing only to chromosome ends. In addition, strong sequence similarity of their gag proteins indicates that these coding regions share a common ancestor. These findings led to the assumption that HeT-A andTART are closely related. However, we now find that these elements produce quite different sets of transcripts. HeT-Aproduces only sense-strand transcripts of the full-length element, whereas TART produces both sense and antisense full-length RNAs, with antisense transcripts in more than 10-fold excess over sense RNA. In addition, features of TART sequence organization resemble those of a subclass of non-LTR elements characterized by unequal terminal repeats. Thus, the ancestral gag sequence appears to have become incorporated in two different types of elements, possibly with different functions in the telomere. HeT-Atranscripts are found in both nuclear and cytoplasmic cell fractions, consistent with roles as both mRNA and transposition template. In contrast, both sense and antisense TART transcripts are almost entirely concentrated in nuclear fractions. Also,TART open reading frame 2 probes detect a cytoplasmic mRNA for reverse transcriptase (RT), with no similarity to TARTsequence 5′ or 3′ of the RT coding region. This RNA could be a processed TART transcript or the product of a “free-standing” RT gene. Either origin would be novel. The distinctive transcription patterns of both HeT-A andTART are conserved in Drosophila yakuba, despite significant sequence divergence. The conservation argues that these sets of transcripts are important to the function(s) ofHeT-A and TART.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Tao Xue ◽  
Han Zhang ◽  
Yuanyuan Zhang ◽  
Shuqin Wei ◽  
Qiujie Chao ◽  
...  

Abstract Background Pinellia ternata is native to China and has been used as a traditional herb due to its antiemetic, antitussive, analgesic, and anxiolytic effects. When exposed to strong light intensity and high temperature during the reproductive growth process, P. ternata withers in a phenomenon known as “sprout tumble”, which largely limits tuber production. Shade was previously found to delay sprout tumble formation (STF); however, no information exists regarding this process at the molecular level. Hence, we determined the genes involved in tuber development and STF in P. ternata. Results Compared to that with natural sun-light (control), shade significantly induced chlorophyll accumulation, increased chlorophyll fluorescence parameters including initial fluorescence, maximal fluorescence, and qP, and dramatically repressed chlorophyll a:b and NPQ. Catalase (CAT) activity was largely induced by shade, and tuber products were largely increased in this environment. Transcriptome profiles of P. ternata grown in natural sun-light and shaded environments were analyzed by a combination of next generation sequencing (NGS) and third generation single-molecule real-time (SMRT) sequencing. Corrections of SMRT long reads based on NGS short reads yielded 136,163 non-redundant transcripts, with an average N50 length of 2578 bp. In total, 6738 deferentially-expressed genes (DEGs) were obtained from the comparisons, specifically D5S vs D5CK, D20S vs D20CK, D20S vs D5S, and D20CK vs D5CK, of which, 6384 DEGs (94.8%) were generated from the D20S vs D20CK comparison. Gene annotation and functional analyses revealed that these genes were related to auxin signal transduction, polysaccharide and sugar metabolism, phenylpropanoid biosynthesis, and photosynthesis. Moreover, the expression of genes enriched in photosynthesis appeared to be significantly altered by shade. The expression patterns of 16 candidate genes were consistent with changes in their transcript abundance as identified by RNA-Seq, and these might contribute to STF and tuber production. Conclusion The full-length transcripts identified in this study have provided a more accurate depiction of P. ternata gene transcription. Further, we identified potential genes involved in STF and tuber growth. Such data could serve as a genetic resource and a foundation for further research on this important traditional herb.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Md. Tofazzal Hossain ◽  
Yin Peng ◽  
Shengzhong Feng ◽  
Yanjie Wei

Circular RNAs (circRNAs) are formed by joining the 3′ and 5′ ends of RNA molecules. Identification of circRNAs is an important part of circRNA research. The circRNA prediction methods can predict the circRNAs with start and end positions in the chromosome but cannot identify the full-length circRNA sequences. We present an R package FcircSEC (Full Length circRNA Sequence Extraction and Classification) to extract the full-length circRNA sequences based on gene annotation and the output of any circRNA prediction tools whose output has a chromosome, start and end positions, and a strand for each circRNA. To validate FcircSEC, we have used three databases, circbase, circRNAdb, and plantcircbase. With information such as the chromosome and strand of each circRNA as the input, the identified sequences by FcircSEC are consistent with the databases. The novelty of FcircSEC is that it can take the output of state-of-the-art circRNA prediction tools as input and is applicable for human and other species. We also classify the circRNAs as exonic, intronic, and others. The R package FcircSEC is freely available.


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