scholarly journals ALTERNATIVELY POLYADENYLATED CALPASTATIN TRANSCRIPTS IN BOVINE MUSCLES

2020 ◽  
Vol 31 (1) ◽  
pp. 45-51
Author(s):  
M.F. Casale ◽  
C. Silvestro ◽  
P.M. Corva ◽  
L.A. Soria
Keyword(s):  
Alternative Splicing ◽  
Beef Cattle ◽  
Relative Abundance ◽  
Alternative Polyadenylation ◽  
Triceps Brachii ◽  
Beef Tenderness ◽  
Alternatively Spliced ◽  
Polyadenylation Sites ◽  
Race Pcr ◽  
Definition Of

Calpastatin activity has a key role in the tenderization process that occurs during postmortem storage of meat under refrigerated conditioning. The regulation of calpastatin (CAST) expression is highly complex, the gene has four putative promoters and at least three different polyadenylation sites, and it is also alternatively spliced. We investigated the presence of alternative polyadenylation (APA) isoforms of CAST transcripts in three muscles (infraspinatus, triceps brachii and semitendinosus) of two bovine breeds (Angus and Brahman). The 3´ RACE-PCR was used to specifically amplify the different APA sites. The amplified fragments were cloned and sequenced. Sequencing confirmed the existence of three expected polyadenylation sites corresponding to short, medium and long polyadenylated transcripts. Also, transcripts with a novel APA site were found in the three muscles of both breeds. Because the same APAs isoforms were found between muscles and breeds, we could hypothesize a possible contribution to the relative abundance of different isoforms, probably in coordination with promoter preference and alternative splicing. This knowledge would be useful in the design of future experiments to analyze differential expression of CAST isoforms and their contribution to the definition of beef tenderness. Key words: Beef cattle; Alternative polyadenylation; 3´ RACE-PCR.

scholarly journals Differential contribution of transcriptomic regulatory layers in the definition of neuronal identity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kevin C. H. Ha ◽  
Timothy Sterne-Weiler ◽  
Quaid Morris ◽  
Robert J. Weatheritt ◽  
Benjamin J. Blencowe
Keyword(s):  
Alternative Splicing ◽  
Expression Patterns ◽  
Alternative Polyadenylation ◽  
Neuronal Identity ◽  
Relative Contribution ◽  
Stage Of Development ◽  
Neuronal Subtype ◽  
Definition Of ◽  
And Function ◽  
Type Specification

AbstractPrevious transcriptomic profiling studies have typically focused on separately analyzing mRNA expression, alternative splicing and alternative polyadenylation differences between cell and tissue types. However, the relative contribution of these three transcriptomic regulatory layers to cell type specification is poorly understood. This question is particularly relevant to neurons, given their extensive heterogeneity associated with brain location, morphology and function. In the present study, we generated profiles for the three regulatory layers from developmentally and regionally distinct subpopulations of neurons from the mouse hippocampus and broader nervous system. Multi-omics factor analyses revealed differing contributions of each transcriptomic layer in the discrimination of neurons based on their stage of development, region, and function. Importantly, profiles of differential alternative splicing and polyadenylation better discriminated specific neuronal subtype populations than gene expression patterns. These results provide evidence for differential relative contributions of coordinated gene regulatory layers in the specification of neuronal subtypes.

scholarly journals Interactions between RNA m6A modification, alternative splicing, and poly(A) tail revealed by MePAIso-seq2

2021 ◽  
Author(s):  
Yusheng Liu ◽  
Yiwei Zhang ◽  
Falong Lu ◽  
Jiaqiang Wang
Keyword(s):  
Alternative Splicing ◽  
Embryonic Stem ◽  
Alternative Polyadenylation ◽  
Tail Length ◽  
Mouse Cell ◽  
Full Length ◽  
New Method ◽  
Rna Immunoprecipitation ◽  
Polyadenylation Sites ◽  
End Capping

RNA post-transcriptional regulation involves 5-end capping, 3-poly(A) tailing (including polyadenylation sites, tail length, and non-A residues), alternative splicing, and chemical modifications including N6-methyladenosine (m6A). Studying the interplay of m6A, alternative splicing, alternative polyadenylation sites, poly(A) tail length, and non-A residues in poly(A) tails requires monitoring them simultaneously on one transcript, however strategies to achieve this are lacking. Therefore, we developed a new method, combining m6A-specific methylated RNA immunoprecipitation and the PacBio-based, tail-included, full-length RNA sequencing approach PAIso-seq2, which we have named m6A and poly(A) inclusive RNA isoform sequencing 2 (MePAIso-seq2). Using MePAIso-seq2, we revealed that m6A promotes and inhibits a similar number of alternative splicing events in mouse cell lines, showing that m6A does affect alternative splicing. In contrast, no correlation was detected between m6A and alternative polyadenylation sites choice. Surprisingly, we found that m6A-modified RNAs possess longer poly(A) tails and a lower proportion of poly(A) tails containing non-A residues, especially in mouse embryonic stem cells. Together, we developed a new method to detect full-length m6A-modified RNAs to comprehensively study the relationships between m6A, alternative splicing, and poly(A) tailing, laying a foundation for further exploration of the functional coordination of different RNA post-transcriptional modifications.

scholarly journals SRSF3 and SRSF7 modulate 3′UTR length through suppression or activation of proximal polyadenylation sites and regulation of CFIm levels

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Oliver Daniel Schwich ◽  
Nicole Blümel ◽  
Mario Keller ◽  
Marius Wegener ◽  
Samarth Thonta Setty ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Mrna Export ◽  
Domain Architecture ◽  
Alternative Polyadenylation ◽  
Sr Proteins ◽  
Untranslated Regions ◽  
Dual Function ◽  
Independent Manner ◽  
Polyadenylation Sites ◽  
Selection Of

Abstract Background Alternative polyadenylation (APA) refers to the regulated selection of polyadenylation sites (PASs) in transcripts, which determines the length of their 3′ untranslated regions (3′UTRs). We have recently shown that SRSF3 and SRSF7, two closely related SR proteins, connect APA with mRNA export. The mechanism underlying APA regulation by SRSF3 and SRSF7 remained unknown. Results Here we combine iCLIP and 3′-end sequencing and find that SRSF3 and SRSF7 bind upstream of proximal PASs (pPASs), but they exert opposite effects on 3′UTR length. SRSF7 enhances pPAS usage in a concentration-dependent but splicing-independent manner by recruiting the cleavage factor FIP1, generating short 3′UTRs. Protein domains unique to SRSF7, which are absent from SRSF3, contribute to FIP1 recruitment. In contrast, SRSF3 promotes distal PAS (dPAS) usage and hence long 3′UTRs directly by counteracting SRSF7, but also indirectly by maintaining high levels of cleavage factor Im (CFIm) via alternative splicing. Upon SRSF3 depletion, CFIm levels decrease and 3′UTRs are shortened. The indirect SRSF3 targets are particularly sensitive to low CFIm levels, because here CFIm serves a dual function; it enhances dPAS and inhibits pPAS usage by binding immediately downstream and assembling unproductive cleavage complexes, which together promotes long 3′UTRs. Conclusions We demonstrate that SRSF3 and SRSF7 are direct modulators of pPAS usage and show how small differences in the domain architecture of SR proteins can confer opposite effects on pPAS regulation.

scholarly journals Splicing-associated chromatin signatures: a combinatorial and position-dependent role for histone marks in splicing definition

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
E. Agirre ◽  
A. J. Oldfield ◽  
N. Bellora ◽  
A. Segelle ◽  
R. F. Luco
Keyword(s):  
Alternative Splicing ◽  
Rna Binding ◽  
Embryonic Stem ◽  
Chromatin Modifications ◽  
Histone Marks ◽  
Splicing Regulators ◽  
Machine Learning Approach ◽  
Alternatively Spliced ◽  
Rna Motif ◽  
Regulation Changes

AbstractAlternative splicing relies on the combinatorial recruitment of splicing regulators to specific RNA binding sites. Chromatin has been shown to impact this recruitment. However, a limited number of histone marks have been studied at a global level. In this work, a machine learning approach, applied to extensive epigenomics datasets in human H1 embryonic stem cells and IMR90 foetal fibroblasts, has identified eleven chromatin modifications that differentially mark alternatively spliced exons depending on the level of exon inclusion. These marks act in a combinatorial and position-dependent way, creating characteristic splicing-associated chromatin signatures (SACS). In support of a functional role for SACS in coordinating splicing regulation, changes in the alternative splicing of SACS-marked exons between ten different cell lines correlate with changes in SACS enrichment levels and recruitment of the splicing regulators predicted by RNA motif search analysis. We propose the dynamic nature of chromatin modifications as a mechanism to rapidly fine-tune alternative splicing when necessary.

scholarly journals Aptardi predicts polyadenylation sites in sample-specific transcriptomes using high-throughput RNA sequencing and DNA sequence

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ryan Lusk ◽  
Evan Stene ◽  
Farnoush Banaei-Kashani ◽  
Boris Tabakoff ◽  
Katerina Kechris ◽  
...  
Keyword(s):  
Rna Sequencing ◽  
Dna Sequence ◽  
Mammalian Species ◽  
Alternative Polyadenylation ◽  
Sequence Information ◽  
Rna Seq ◽  
Average Precision ◽  
Polyadenylation Sites ◽  
Dna Nucleotide Sequence

AbstractAnnotation of polyadenylation sites from short-read RNA sequencing alone is a challenging computational task. Other algorithms rooted in DNA sequence predict potential polyadenylation sites; however, in vivo expression of a particular site varies based on a myriad of conditions. Here, we introduce aptardi (alternative polyadenylation transcriptome analysis from RNA-Seq data and DNA sequence information), which leverages both DNA sequence and RNA sequencing in a machine learning paradigm to predict expressed polyadenylation sites. Specifically, as input aptardi takes DNA nucleotide sequence, genome-aligned RNA-Seq data, and an initial transcriptome. The program evaluates these initial transcripts to identify expressed polyadenylation sites in the biological sample and refines transcript 3′-ends accordingly. The average precision of the aptardi model is twice that of a standard transcriptome assembler. In particular, the recall of the aptardi model (the proportion of true polyadenylation sites detected by the algorithm) is improved by over three-fold. Also, the model—trained using the Human Brain Reference RNA commercial standard—performs well when applied to RNA-sequencing samples from different tissues and different mammalian species. Finally, aptardi’s input is simple to compile and its output is easily amenable to downstream analyses such as quantitation and differential expression.

scholarly journals Trans-acting Factors Required for Inclusion of Regulated Exons in the Ultrabithorax mRNAs of Drosophila melanogaster

Genetics ◽  
1999 ◽  
Vol 151 (4) ◽  
pp. 1517-1529 ◽  
Author(s):  
James M Burnette ◽  
Allyson R Hatton ◽  
A Javier Lopez
Keyword(s):  
Drosophila Melanogaster ◽  
Alternative Splicing ◽  
P Element ◽  
Splicing Factors ◽  
Loss Of Function ◽  
Large Collection ◽  
Splicing Pattern ◽  
Alternatively Spliced ◽  
Hypomorphic Alleles

Abstract Alternatively spliced Ultrabithorax mRNAs differ by the presence of internal exons mI and mII. Two approaches were used to identify trans-acting factors required for inclusion of these cassette exons. First, mutations in a set of genes implicated in the control of other alternative splicing decisions were tested for dominant effects on the Ubx alternative splicing pattern. To identify additional genes involved in regulation of Ubx splicing, a large collection of deficiencies was tested first for dominant enhancement of the haploinsufficient Ubx haltere phenotype and second for effects on the splicing pattern. Inclusion of the cassette exons in Ubx mRNAs was reduced strongly in heterozygotes for hypomorphic alleles of hrp48, which encodes a member of the hnRNP A/B family and is implicated in control of P-element splicing. Significant reductions of mI and mII inclusion were also observed in heterozygotes for loss-of-function alleles of virilizer, fl(2)d, and crooked neck. The products of virilizer and fl(2)d are also required for Sxl autoregulation at the level of splicing; crooked neck encodes a protein with structural similarities to yeast-splicing factors Prp39p and Prp42p. Deletion of at least five other loci caused significant reductions in the inclusion of mI and/or mII. Possible roles of identified factors are discussed in the context of the resplicing strategy for generation of alternative Ubx mRNAs.

scholarly journals Short linear motif acquisition, exon formation and alternative splicing determine a pathway to diversity for NCoR-family co-repressors

Open Biology ◽  
2015 ◽  
Vol 5 (8) ◽  
pp. 150063 ◽  
Author(s):  
Stephen Short ◽  
Tessa Peterkin ◽  
Matthew Guille ◽  
Roger Patient ◽  
Colin Sharpe
Keyword(s):  
Alternative Splicing ◽  
Gene Sequence ◽  
Species Differences ◽  
Single Point ◽  
Stem Cell Differentiation ◽  
Single Point Mutation ◽  
Linear Motif ◽  
Cellular Context ◽  
Alternatively Spliced ◽  
Linear Motifs

Vertebrate NCoR-family co-repressors play central roles in the timing of embryo and stem cell differentiation by repressing the activity of a range of transcription factors. They interact with nuclear receptors using short linear motifs (SLiMs) termed co-repressor for nuclear receptor (CoRNR) boxes. Here, we identify the pathway leading to increasing co-repressor diversity across the deuterostomes. The final complement of CoRNR boxes arose in an ancestral cephalochordate, and was encoded in one large exon; the urochordates and vertebrates then split this region between 10 and 12 exons. In Xenopus , alternative splicing is prevalent in NCoR2, but absent in NCoR1. We show for one NCoR1 exon that alternative splicing can be recovered by a single point mutation, suggesting NCoR1 lost the capacity for alternative splicing. Analyses in Xenopus and zebrafish identify that cellular context, rather than gene sequence, predominantly determines species differences in alternative splicing. We identify a pathway to diversity for the NCoR family beginning with the addition of a SLiM, followed by gene duplication, the generation of alternatively spliced isoforms and their differential deployment.

scholarly journals Expression of Alternatively Spliced Sodium Channel α-Subunit Genes

2004 ◽  
Vol 279 (44) ◽  
pp. 46234-46241 ◽  
Author(s):  
Christopher K. Raymond ◽  
John Castle ◽  
Philip Garrett-Engele ◽  
Christopher D. Armour ◽  
Zhengyan Kan ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Sodium Channel ◽  
Dorsal Root Ganglia ◽  
Dorsal Root ◽  
Genomic Sequence ◽  
Molecular Medicine ◽  
Primate Model ◽  
Α Subunit ◽  
Alternatively Spliced ◽  
Splicing Patterns

Molecular medicine requires the precise definition of drug targets, and tools are now in place to provide genome-wide information on the expression and alternative splicing patterns of any known gene. DNA microarrays were used to monitor transcript levels of the nine well-characterized α-subunit sodium channel genes across a broad range of tissues from cynomolgus monkey, a non-human primate model. Alternative splicing of human transcripts for a subset of the genes that are expressed in dorsal root ganglia, SCN8A (Nav1.6), SCN9A (Nav1.7), and SCN11A (Nav1.9) was characterized in detail. Genomic sequence analysis among gene family paralogs and between cross-species orthologs suggested specific alternative splicing events within transcripts of these genes, all of which were experimentally confirmed in human tissues. Quantitative PCR revealed that certain alternative splice events are uniquely expressed in dorsal root ganglia. In addition to characterization of human transcripts, alternatively spliced sodium channel transcripts were monitored in a rat model for neuropathic pain. Consistent down-regulation of all transcripts was observed, as well as significant changes in the splicing patterns of SCN8A and SCN9A.

Sign in / Sign up

Export Citation Format

Share Document