Insights into transcriptional characteristics and homoeolog expression bias of embryo and de-embryonated kernels in developing grain through RNA-Seq and Iso-Seq

2019 ◽  
Vol 19 (6) ◽  
pp. 919-932 ◽  
Author(s):  
Jun Wei ◽  
Hong Cao ◽  
Jing-dong Liu ◽  
Jing-hong Zuo ◽  
Yu Fang ◽  
...  
Keyword(s):  
Rna Seq ◽  
Expression Bias ◽  
Homoeolog Expression Bias

scholarly journals LCM and RNA-seq analyses revealed roles of cell cycle and translational regulation and homoeolog expression bias in cotton fiber cell initiation

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Atsumi Ando ◽  
Ryan C. Kirkbride ◽  
Don C. Jones ◽  
Jane Grimwood ◽  
Z. Jeffrey Chen
Keyword(s):  
Cell Cycle ◽  
Cotton Fiber ◽  
Epidermal Cells ◽  
Fiber Cell ◽  
Epidermal Layer ◽  
Rna Seq ◽  
Expression Bias ◽  
Homoeolog Expression Bias ◽  
Ribosome Biosynthesis ◽  
Fiber Cell Initiation

Abstract Background Cotton fibers provide a powerful model for studying cell differentiation and elongation. Each cotton fiber is a singular and elongated cell derived from epidermal-layer cells of a cotton seed. Efforts to understand this dramatic developmental shift have been impeded by the difficulty of separation between fiber and epidermal cells. Results Here we employed laser-capture microdissection (LCM) to separate these cell types. RNA-seq analysis revealed transitional differences between fiber and epidermal-layer cells at 0 or 2 days post anthesis. Specifically, down-regulation of putative cell cycle genes was coupled with upregulation of ribosome biosynthesis and translation-related genes, which may suggest their respective roles in fiber cell initiation. Indeed, the amount of fibers in cultured ovules was increased by cell cycle progression inhibitor, Roscovitine, and decreased by ribosome biosynthesis inhibitor, Rbin-1. Moreover, subfunctionalization of homoeologs was pervasive in fiber and epidermal cells, with expression bias towards 10% more D than A homoeologs of cell cycle related genes and 40–50% more D than A homoeologs of ribosomal protein subunit genes. Key cell cycle regulators were predicted to be epialleles in allotetraploid cotton. MYB-transcription factor genes displayed expression divergence between fibers and ovules. Notably, many phytohormone-related genes were upregulated in ovules and down-regulated in fibers, suggesting spatial-temporal effects on fiber cell development. Conclusions Fiber cell initiation is accompanied by cell cycle arrest coupled with active ribosome biosynthesis, spatial-temporal regulation of phytohormones and MYB transcription factors, and homoeolog expression bias of cell cycle and ribosome biosynthesis genes. These valuable genomic resources and molecular insights will help develop breeding and biotechnological tools to improve cotton fiber production.

scholarly journals Homoeolog expression bias in allopolyploid oleaginous marine diatom Fistulifera solaris

BMC Genomics ◽  
2018 ◽  
Vol 19 (1) ◽  
Author(s):  
Tatsuhiro Nomaguchi ◽  
Yoshiaki Maeda ◽  
Tomoko Yoshino ◽  
Toru Asahi ◽  
Leila Tirichine ◽  
...  
Keyword(s):  
Marine Diatom ◽  
Expression Bias ◽  
Homoeolog Expression Bias

scholarly journals Homoeolog expression bias and expression level dominance (ELD) in four tissues of natural allotetraploid Brassica napus

2020 ◽  
Author(s):  
Mengdi Li ◽  
Ruihua Wang ◽  
Xiaoming Wu ◽  
Jianbo Wang
Keyword(s):  
Gene Expression ◽  
Brassica Napus ◽  
Expression Patterns ◽  
Expression Level ◽  
Gene Expression Patterns ◽  
Homologous Gene ◽  
Gene Pairs ◽  
Expression Bias ◽  
Homoeolog Expression Bias ◽  
Expression Level Dominance

Abstract Background: Allopolyploidy is widespread in angiosperms, and they can coordinate two or more different genomes through genetic and epigenetic modifications to exhibit stronger vigor and adaptability. To explore the changes in homologous gene expression patterns in the natural allotetraploid Brassica napus (AnAnCnCn) relative to its two diploid progenitors, B. rapa (ArAr) and B. oleracea (CoCo), after approximately 7,500 years of domestication, the global gene pair expression patterns in four major tissues (stems, leaves, flowers and siliques) of these three species were analyzed using an RNA sequencing approach. Results: The results showed that the ‘transcriptomic shock’ phenomenon was alleviated in natural B. napus after approximately 7,500 years of natural domestication, and most differentially expressed genes (DEGs) in B. napus were downregulated relative to those in its two diploid progenitors. The KEGG analysis indicated that three pathways related to photosynthesis were enriched in both comparison groups (AnAnCnCn vs ArAr and AnAnCnCn vs CoCo), and these pathways were all downregulated in four tissues of B. napus. In addition, homoeolog expression bias and expression level dominance (ELD) in B. napus were thoroughly studied through analysis of expression levels of 27609 B. rapa-B. oleracea orthologous gene pairs. The overwhelming majority of gene pairs (an average of 86.7%) in B. napus maintained their expression pattern in two diploid progenitors, and approximately 78.1% of the gene pairs showed expression bias with a preference toward the A subgenome. Overall, an average of 48%, 29.7% and 22.3% homologous gene pairs exhibited additive expression, ELD and transgressive expression in B. napus, respectively. The ELD bias varies from tissue to tissue; specifically, more gene pairs in stems and siliques showed ELD-A, whereas the opposite was observed in leaves and flowers. More transgressive upregulation, rather than downregulation, was observed in gene pairs of B. napus. Conclusions: In general, these results may provide a comprehensive understanding of the changes in homologous gene expression patterns in natural B. napus after approximately 7,500 years of evolution and domestication and may enhance our understanding of allopolyploidy.

scholarly journals Unperturbed Expression Bias of Imprinted Genes in Schizophrenia

2018 ◽  
Author(s):  
Attila Gulyás-Kovács ◽  
Ifat Keydar ◽  
Eva Xia ◽  
Menachem Fromer ◽  
Gabriel Hoffman ◽  
...  
Keyword(s):  
Joint Analysis ◽  
Imprinted Genes ◽  
Rna Seq ◽  
Specific Expression ◽  
Human Genes ◽  
Expression Bias ◽  
Dorsolateral Prefrontal ◽  
Allele Specific ◽  
And Control ◽  
Allelic Bias

AbstractHow gene expression correlates with schizophrenia across individuals is beginning to be examined through analyses of RNA-seq from post-mortem brains of individuals with disease and control brains. Here we focus on variation in allele-specific expression, following up on the Common Mind Consortium (CMC) RNA-seq experiments of nearly 600 human dorsolateral prefrontal cortex (DLPFC) samples. Analyzing the extent of allelic expression bias—a hallmark of imprinting—we find that the number of imprinted human genes is consistent with lower estimates (≈0.5% of all genes) and thus contradicts much higher estimates. Moreover, the handful of putatively imprinted genes are all in close genomic proximity to known imprinted genes. Joint analysis of the imprinted genes across hundreds of individuals allowed us to establish how allelic bias depends on various factors. We find that age and genetic ancestry have gene-specific, differential effect on allelic bias. In contrast, allelic bias appears to be independent of schizophrenia.

scholarly journals Trajectories of Homoeolog-Specific Expression in Allotetraploid Tragopogon castellanus Populations of Independent Origins

2021 ◽  
Vol 12 ◽  
Author(s):  
J. Lucas Boatwright ◽  
Cheng-Ting Yeh ◽  
Heng-Cheng Hu ◽  
Alfonso Susanna ◽  
Douglas E. Soltis ◽  
...  
Keyword(s):  
Gene Dosage ◽  
Expression Patterns ◽  
Genetic Material ◽  
Flowering Plant ◽  
Evolutionary Time ◽  
Specific Expression ◽  
Naturally Occurring ◽  
Expression Bias ◽  
Homoeolog Expression Bias ◽  
Compare And Contrast

Polyploidization can have a significant ecological and evolutionary impact by providing substantially more genetic material that may result in novel phenotypes upon which selection may act. While the effects of polyploidization are broadly reviewed across the plant tree of life, the reproducibility of these effects within naturally occurring, independently formed polyploids is poorly characterized. The flowering plant genus Tragopogon (Asteraceae) offers a rare glimpse into the intricacies of repeated allopolyploid formation with both nascent (< 90 years old) and more ancient (mesopolyploids) formations. Neo- and mesopolyploids in Tragopogon have formed repeatedly and have extant diploid progenitors that facilitate the comparison of genome evolution after polyploidization across a broad span of evolutionary time. Here, we examine four independently formed lineages of the mesopolyploid Tragopogon castellanus for homoeolog expression changes and fractionation after polyploidization. We show that expression changes are remarkably similar among these independently formed polyploid populations with large convergence among expressed loci, moderate convergence among loci lost, and stochastic silencing. We further compare and contrast these results for T. castellanus with two nascent Tragopogon allopolyploids. While homoeolog expression bias was balanced in both nascent polyploids and T. castellanus, the degree of additive expression was significantly different, with the mesopolyploid populations demonstrating more non-additive expression. We suggest that gene dosage and expression noise minimization may play a prominent role in regulating gene expression patterns immediately after allopolyploidization as well as deeper into time, and these patterns are conserved across independent polyploid lineages.

scholarly journals Homoeolog expression bias and expression level dominance in allopolyploids

2012 ◽  
Vol 196 (4) ◽  
pp. 966-971 ◽  
Author(s):  
C. E. Grover ◽  
J. P. Gallagher ◽  
E. P. Szadkowski ◽  
M. J. Yoo ◽  
L. E. Flagel ◽  
...  
Keyword(s):  
Expression Level ◽  
Expression Bias ◽  
Homoeolog Expression Bias ◽  
Expression Level Dominance

scholarly journals Subgenome Bias and Temporal Postponement of Gene Expression Contributes to the Distinctions of Fiber Quality in Gossypium Species

2021 ◽  
Vol 12 ◽  
Author(s):  
Huan Mei ◽  
Bowen Qi ◽  
Zegang Han ◽  
Ting Zhao ◽  
Menglan Guo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Fiber Quality ◽  
Expression Patterns ◽  
Rna Seq ◽  
Hub Genes ◽  
Hub Gene ◽  
Expression Of Genes ◽  
Multiple Dimensions ◽  
Cotton Species ◽  
Expression Bias

As two cultivated widely allotetraploid cotton species, although Gossypium hirsutum and Gossypium barbadense evolved from the same ancestor, they differ in fiber quality; the molecular mechanism of that difference should be deeply studied. Here, we performed RNA-seq of fiber samples from four G. hirsutum and three G. barbadense cultivars to compare their gene expression patterns on multiple dimensions. We found that 15.90–37.96% of differentially expressed genes showed biased expression toward the A or D subgenome. In particular, interspecific biased expression was exhibited by a total of 330 and 486 gene pairs at 10 days post-anthesis (DPA) and 20 DPA, respectively. Moreover, 6791 genes demonstrated temporal differences in expression, including 346 genes predominantly expressed at 10 DPA in G. hirsutum (TM-1) but postponed to 20 DPA in G. barbadense (Hai7124), and 367 genes predominantly expressed at 20 DPA in TM-1 but postponed to 25 DPA in Hai7124. These postponed genes mainly participated in carbohydrate metabolism, lipid metabolism, plant hormone signal transduction, and starch and sucrose metabolism. In addition, most of the co-expression network and hub genes involved in fiber development showed asymmetric expression between TM-1 and Hai7124, like three hub genes detected at 10 DPA in TM-1 but not until 25 DPA in Hai7124. Our study provides new insights into interspecific expression bias and postponed expression of genes associated with fiber quality, which are mainly tied to asymmetric hub gene network. This work will facilitate further research aimed at understanding the mechanisms underlying cotton fiber improvement.

scholarly journals Homoeolog expression bias and expression level dominance (ELD) in four tissues of natural allotetraploid Brassica napus

2020 ◽  
Author(s):  
Mengdi Li ◽  
Ruihua Wang ◽  
Xiaoming Wu ◽  
Jianbo Wang
Keyword(s):  
Gene Expression ◽  
Brassica Napus ◽  
Expression Patterns ◽  
Expression Level ◽  
Gene Expression Patterns ◽  
Homologous Gene ◽  
Gene Pairs ◽  
Expression Bias ◽  
Homoeolog Expression Bias ◽  
Expression Level Dominance

Abstract Background: Allopolyploidy is widespread in angiosperms, and they can coordinate two or more different genomes through genetic and epigenetic modifications to exhibit stronger vigor and adaptability. To explore the changes in homologous gene expression patterns in the natural allotetraploid Brassica napus (AnAnCnCn) relative to its two diploid progenitors, B. rapa (ArAr) and B. oleracea (CoCo), after approximately 7,500 years of domestication, the global gene pair expression patterns in four major tissues (stems, leaves, flowers and siliques) of these three species were analyzed using an RNA sequencing approach. Results: The results showed that the ‘transcriptomic shock’ phenomenon was alleviated in natural B. napus after approximately 7,500 years of natural domestication, and most differentially expressed genes (DEGs) in B. napus were downregulated relative to those in its two diploid progenitors. The KEGG analysis indicated that three pathways related to photosynthesis were enriched in both comparison groups (AnAnCnCn vs ArAr and AnAnCnCn vs CoCo), and these pathways were all downregulated in four tissues of B. napus. In addition, homoeolog expression bias and expression level dominance (ELD) in B. napus were thoroughly studied through analysis of expression levels of 27609 B. rapa-B. oleracea orthologous gene pairs. The overwhelming majority of gene pairs (an average of 86.7%) in B. napus maintained their expression pattern in two diploid progenitors, and approximately 78.1% of the gene pairs showed expression bias with a preference toward the A subgenome. Overall, an average of 48%, 29.7% and 22.3% homologous gene pairs exhibited additive expression, ELD and transgressive expression in B. napus, respectively. The ELD bias varies from tissue to tissue; specifically, more gene pairs in stems and siliques showed ELD-A, whereas the opposite was observed in leaves and flowers. More transgressive upregulation, rather than downregulation, was observed in gene pairs of B. napus. Conclusions: In general, these results may provide a comprehensive understanding of the changes in homologous gene expression patterns in natural B. napus after approximately 7,500 years of evolution and domestication and may enhance our understanding of allopolyploidy.

scholarly journals Co-expression analysis is biased by a mean-correlation relationship

2020 ◽  
Author(s):  
Yi Wang ◽  
Stephanie C. Hicks ◽  
Kasper D. Hansen
Keyword(s):  
Expression Analysis ◽  
Protein Interaction Data ◽  
Quantile Normalization ◽  
Rna Seq ◽  
Correlation Relationship ◽  
Biologically Relevant ◽  
Protein Protein Interaction ◽  
Expression Bias ◽  
Highly Expressed Genes ◽  
Highly Correlated

AbstractEstimates of correlation between pairs of genes in co-expression analysis are commonly used to construct networks among genes using gene expression data. Here, we show that the distribution of such correlations depend on the expression level of the involved genes, which we refer to this as a mean-correlation relationship in RNA-seq data, both bulk and single-cell. This dependence introduces a bias in co-expression analysis whereby highly expressed genes are more likely to be highly correlated. Such a relationship is not observed in protein-protein interaction data, suggesting that it is not reflecting biology. Ignoring this bias can lead to missing potentially biologically relevant pairs of genes that are lowly expressed, such as transcription factors. To address this problem, we introduce spatial quantile normalization (SpQN), a method for normalizing local distributions in a correlation matrix. We show that spatial quantile normalization removes the mean-correlation relationship and corrects the expression bias in network reconstruction.

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