scholarly journals Transcriptome Reveals Allele Contribution to Heterosis in Maize

2021 ◽  
Vol 12 ◽  
Author(s):  
Jianzhong Wu ◽  
Dequan Sun ◽  
Qian Zhao ◽  
Hongjun Yong ◽  
Degui Zhang ◽  
...  

Heterosis, which has greatly increased maize yields, is associated with gene expression patterns during key developmental stages that enhance hybrid phenotypes relative to parental phenotypes. Before heterosis can be more effectively used for crop improvement, hybrid maize developmental gene expression patterns must be better understood. Here, six maize hybrids, including the popular hybrid Zhengdan958 (ZC) from China, were studied. Maize hybrids created in-house were generated using an incomplete diallel cross (NCII)-based strategy from four elite inbred parental lines. Differential gene expression (DEG) profiles corresponding to three developmental stages revealed that hybrid partial expression patterns exhibited complementarity of expression of certain parental genes, with parental allelic expression patterns varying both qualitatively and quantitatively in hybrids. Single-parent expression (SPE) and parent-specific expression (PSE) types of qualitative variation were most prevalent, 43.73 and 41.07% of variation, respectively. Meanwhile, negative super-dominance (NSD) and positive super-dominance (PSD) types of quantitative variation were most prevalent, 31.06 and 24.30% of variation, respectively. During the early reproductive growth stage, the gene expression pattern differed markedly from other developmental stage patterns, with allelic expression patterns during seed development skewed toward low-value parental alleles in hybrid seeds exhibiting significant quantitative variation-associated superiority. Comparisons of qualitative gene expression variation rates between ZC and other hybrids revealed proportions of SPE-DEGs (41.36%) in ZC seed DEGs that significantly exceeded the average proportion of SPE-DEGs found in seeds of other hybrids (28.36%). Importantly, quantitative gene expression variation rate comparisons between ZC and hybrids, except for transgressive expression, revealed that the ZC rate exceeded the average rate for other hybrids, highlighting the importance of partial gene expression in heterosis. Moreover, enriched ZC DEGs exhibiting distinct tissue-specific expression patterns belonged to four biological pathways, including photosynthesis, plant hormone signal transduction, biology metabolism and biosynthesis. These results provide valuable technical insights for creating hybrids exhibiting strong heterosis.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2897-2897
Author(s):  
Torsten Haferlach ◽  
Helmut Loeffler ◽  
Alexander Kohlmann ◽  
Martin Dugas ◽  
Wolfgang Hiddemann ◽  
...  

Abstract Balanced chromosomal rearrangements leading to fusion genes on the molecular level define distinct biological subsets in AML. The four balanced rearrangements (t(15;17), t(8;21), inv(16), and 11q23/MLL) show a close correlation to cytomorphology and gene expression patterns. We here focused on seven AML with t(8;16)(p11;p13). This translocation is rare (7/3515 cases in own cohort). It is more frequently found in therapy-related AML than in de novo AML (3/258 t-AML, and 4/3287 de novo, p=0.0003). Cytomorphologically, AML with t(8;16) is characterized by striking features: In all 7 cases the positivity for myeloperoxidase on bone marrow smears was >70% and intriguingly, in parallel >80% of blast cells stained strongly positive for non-specific esterase (NSE) in all cases. Thus, these cases can not be classified according to FAB categories. These data suggest that AML-t(8;16) arise from a very early stem cell with both myeloid and monoblastic potential. Furthermore, we detected erythrophagocytosis in 6/7 cases that was described as specific feature in AML with t(8;16). Four pts. had chromosomal aberrations in addition to t(8;16), 3 of these were t-AML all showing aberrations of 7q. Survival was poor with 0, 1, 1, 2, 20 and 18+ (after alloBMT) mo., one lost to follow-up, respectively. We then analyzed gene expression patterns in 4 cases (Affymetrix U133A+B). First we compared t(8;16) AML with 46 AML FAB M1, 41 M4, 9 M5a, and 16 M5b, all with normal karyotype. Hierachical clustering and principal component analyses (PCA) revealed that t(8;16) AML were intercalating with FAB M4 and M5b and did not cluster near to M1. Thus, monocytic characteristics influence the gene expression pattern stronger than myeloid. Next we compared the t(8;16) AML with the 4 other balanced subtypes according to the WHO classification (t(15;17): 43; t(8;21): 40; inv(16): 49; 11q23/MLL-rearrangements: 50). Using support vector machines the overall accuracy for correct subgroup assignment was 97.3% (10-fold CV), and 96.8% (2/3 training and 1/3 test set, 100 runs). In PCA and hierarchical cluster analysis the t(8;16) were grouped in the vicinity of the 11q23 cases. However, in a pairwise comparison these two subgroups could be discriminated with an accuracy of 94.4% (10-fold CV). Genes with a specific expression in AML-t(8;16) were further investigated in pathway analyses (Ingenuity). 15 of the top 100 genes associated with AML-t(8;16) were involved in the CMYC-pathway with up regulation of BCOR, COXB5, CDK10, FLI1, HNRPA2B1, NSEP1, PDIP38, RAD50, SUPT5H, TLR2 and USP33, and down regulation of ERG, GATA2, NCOR2 and RPS20. CEBP beta, known to play a role in myelomonocytic differentiation, was also up-regulated in t(8;16)-AML. Ten additional genes out of the 100 top differentially expressed genes were also involved in this pathway with up-regulation of DDB2, HIST1H3D, NSAP1, PTPNS1, RAN, USP4, TRIM8, ZNF278 and down regulation of KIT and MBD2. In conclusion, AML with t(8;16) is a specific subtype of AML with unique characteristics in morphology and gene expression patterns. It is more frequently found in t-AML, outcome is inferior in comparison to other AML with balanced translocations. Due to its unique features, it is a candidate for inclusion into the WHO classification as a specific entity.


Genome ◽  
2015 ◽  
Vol 58 (6) ◽  
pp. 305-313 ◽  
Author(s):  
Jagesh Kumar Tiwari ◽  
Sapna Devi ◽  
S. Sundaresha ◽  
Poonam Chandel ◽  
Nilofer Ali ◽  
...  

Genes involved in photoassimilate partitioning and changes in hormonal balance are important for potato tuberization. In the present study, we investigated gene expression patterns in the tuber-bearing potato somatic hybrid (E1-3) and control non-tuberous wild species Solanum etuberosum (Etb) by microarray. Plants were grown under controlled conditions and leaves were collected at eight tuber developmental stages for microarray analysis. A t-test analysis identified a total of 468 genes (94 up-regulated and 374 down-regulated) that were statistically significant (p ≤ 0.05) and differentially expressed in E1-3 and Etb. Gene Ontology (GO) characterization of the 468 genes revealed that 145 were annotated and 323 were of unknown function. Further, these 145 genes were grouped based on GO biological processes followed by molecular function and (or) PGSC description into 15 gene sets, namely (1) transport, (2) metabolic process, (3) biological process, (4) photosynthesis, (5) oxidation-reduction, (6) transcription, (7) translation, (8) binding, (9) protein phosphorylation, (10) protein folding, (11) ubiquitin-dependent protein catabolic process, (12) RNA processing, (13) negative regulation of protein, (14) methylation, and (15) mitosis. RT-PCR analysis of 10 selected highly significant genes (p ≤ 0.01) confirmed the microarray results. Overall, we show that candidate genes induced in leaves of E1-3 were implicated in tuberization processes such as transport, carbohydrate metabolism, phytohormones, and transcription/translation/binding functions. Hence, our results provide an insight into the candidate genes induced in leaf tissues during tuberization in E1-3.


1997 ◽  
Vol 24 (4) ◽  
pp. 423 ◽  
Author(s):  
James O. Berry ◽  
Dennis J. McCormac ◽  
John J. Long ◽  
Joseph Boinski ◽  
Amy C. Corey

Post-transcriptional regulation determines initial C4 gene expression patterns in developing leaves of Amaranthus hypochondriacus, an NAD-ME type C4 dicot. RuBPCase, PEPCase, and PPdK mRNAs are abundant in meristems and in leaf primordia, but are utilised only during specific developmental stages. While each enzyme shows independent patterns of initial mRNA and polypeptide accumulation, cell-specific localisation of the polypeptides occurs prior to cell-specific localisation of the mRNAs. In mature three-coloured leaves of A. tricolor, loss of photosynthetic activity correlates with reductions in the transcription rates of some plastid-encoded genes, reduction and loss of coordination in the translation of RuBPCase polypeptides, and loss of cell-specific accumulation of RuBPCase mRNAs (but not the polypeptides). The mitochondrial NAD-dependent malic enzyme (NAD-ME) provides an example of a basic metabolic enzyme that has acquired specialised gene expression patterns allowing it to function in the C4 pathway. NAD-ME occurs preferentially in photosynthetic tissues, and is specific to bundle sheath cells throughout development. NAD-ME synthesis is regulated by light and development at transcriptional and post-transcriptional levels. The findings summarised here indicate that C4 genes are independently regulated by multiple control mechanisms in response to developmental, environmental, and metabolic signals.


2021 ◽  
Author(s):  
Jiong Wan ◽  
Qiyue Wang ◽  
Jiawen Zhao ◽  
Kuntai Dang ◽  
Zhanyong Guo ◽  
...  

Abstract BackgroundHeterosis has been extensively utilization in plant breeding, however, the underlying molecular mechanism remain largely elusive. Maize (Zea mays), which exhibits strong heterosis, is an ideal material for studying heterosis.ResultsIn this study, there is a faster imbibition and development in reciprocal crossing Zhengdan958 hybrids than in their parent lines during seed germination. To investigate the mechanism of heterosis of maize germination, comparative transcriptomic analyses was conducted between reciprocal crossing hybrids and their parental lines. The gene expression patterns showed that 1324 (47.27%) and 1592 (66.44%) of the different expression genes between hybrids and either parental line display parental dominance up or higher levels in Zhengdan958 and Zhengdan958 reciprocal-cross, respectively. Notably, these genes were mainly enriched in metabolic pathways, including carbon metabolism, glycolysis/gluconeogenesis, protein processing in endoplasmic reticulum, etc.ConclusionOur results provide evidence for the higher expression level genes in hybrid involved in metabolic pathways acting as main contributors to maize seed germinating heterosis. These findings provide new insights into the gene expression variation of maize embryo and improve the understanding of maize seed germination heterosis.


2021 ◽  
Author(s):  
Catriona Munro ◽  
Felipe Zapata ◽  
Mark Howison ◽  
Stefan Siebert ◽  
Casey W Dunn

Background: Siphonophores are complex colonial animals, consisting of asexually-produced bodies (called zooids) that are functionally specialized for specific tasks, including feeding, swimming, and sexual reproduction. Though this extreme functional specialization has captivated biologists for generations, its genomic underpinnings remain unknown. We use RNA-seq to investigate gene expression patterns in five zooids and one specialized tissue (pneumatophore) across seven siphonophore species. Analyses of gene expression across species present several challenges, including identification of comparable expression changes on gene trees with complex histories of speciation, duplication, and loss. Here, we conduct three analyses of expression. First, we examine gene expression within species. Then, we conduct classical analyses examining expression patterns between species. Lastly, we introduce Speciation Branch Filtering, which allows us to examine the evolution of expression in a phylogenetic framework. Results: Within and across species, we identified hundreds of zooid-specific and species-specific genes, as well as a number of putative transcription factors showing differential expression in particular zooids and developmental stages. We found that gene expression patterns tended to be largely consistent in zooids with the same function across species, but also some large lineage-specific shifts in gene expression. Conclusions: Our findings show that patterns of gene expression have the potential to define zooids in colonial organisms. We also show that traditional analyses of the evolution of gene expression focus on the tips of gene phylogenies, identifying large-scale expression patterns that are zooid or species variable. The new explicit phylogenetic approach we propose here focuses on branches (not tips) offering a deeper evolutionary perspective into specific changes in gene expression within zooids along all branches of the gene (and species) trees.


Genes ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 728 ◽  
Author(s):  
Marco Pellino ◽  
Diego Hojsgaard ◽  
Elvira Hörandl ◽  
Timothy F. Sharbel

Apomixis, the asexual reproduction via seeds, is associated to polyploidy and hybridization. To identify possible signatures of apomixis, and possible candidate genes underlying the shift from sex to apomixis, microarray-based gene expression patterns of live microdissected ovules at four different developmental stages were compared between apomictic and sexual individuals of the Ranunculus auricomus complex. Following predictions from previous work on mechanisms underlying apomixis penetrance and expressivity in the genus, gene expression patterns were classified into three categories based on their relative expression in apomicts compared to their sexual parental ancestors. We found evidence of misregulation and differential gene expression between apomicts and sexuals, with the highest number of differences detected during meiosis progression and emergence of aposporous initial (AI) cells, a key developmental stage in the ovule of apomicts where a decision between divergent reproductive pathways takes place. While most of the differentially expressed genes (DEGs) could not be annotated, gene expression was classified into transgressive, parent of origin and ploidy effects. Genes related to gametogenesis and meiosis demonstrated patterns reflective of transgressive and genome dosage effects, which support the hypothesis of a dominant factor controlling apomixis in Ranunculus and modulated by secondary modifiers. Three genes with probable functions in sporogenesis and gametogenesis development are identified and characterized for future studies.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lijun Zhang ◽  
Mingchuan Ma ◽  
Lin Cui ◽  
Longlong Liu

Abstract Background Male sterility (MS) has important applications in hybrid seed production, and the abortion of anthers has been observed in many plant species. While most studies have focused on the genetic factors affecting male sterility, the dynamic gene expression patterns of pollen abortion in male sterile lines have not been fully elucidated. In addition, there is still no hybrid oat that is commercially planted due to the lack of a suitable system of male sterility for hybrid breeding. Results In this study, we cultivated a male sterile oat line and a near-isogenic line by crossbreeding to elucidate the expression patterns of genes that may be involved in sterility. The first reported CA male sterile (CAMS) oat line was used for cross-testing and hybridization experiments and was confirmed to exhibit a type of nuclear sterility controlled by recessive genes. Oat stamens of two lines were sampled at four different developmental stages separately. Paired-end RNA sequencing was performed for each sample and generated 252.84 Gb sequences. There were 295,462 unigenes annotated in public databases in all samples, and we compared the histological characteristics and transcriptomes of oat stamens from the two oat lines at different developmental stages. Our results demonstrate that the sterility of the male sterile oat line occurs in the early stage of stamen development and is primarily attributable to abnormal meiosis and the excessive accumulation of superoxide. Conclusions To the best of our knowledge, this study is the first to decipher the dynamic expression profiles of pollen abortion CAMS and CA male fertile (CAMF) oat lines, which may represent a valuable resource for further studies attempting to understand pollen abortion and anther development in oats.


2021 ◽  
Author(s):  
Emma Berdan ◽  
Claire Merot ◽  
Henrik Pavia ◽  
Kerstin Johannesson ◽  
Maren Wellenreuther ◽  
...  

Inversions often underlie complex adaptive traits, but the genic targets inside them are largely unknown. Gene expression profiling provides a powerful way to link inversions with their phenotypic consequences. We examined the effects of the Cf-Inv(1) inversion in the seaweed fly Coelopa frigida on gene expression variation across sexes and life stages. Our analyses revealed that Cf-Inv(1) shapes global expression patterns but the extent of this effect is variable with much stronger effects in adults than larvae. Furthermore, within adults, both common as well as sex specific patterns were found. The vast majority of these differentially expressed genes mapped to Cf-Inv(1). However, genes that were differentially expressed in a single context (i.e. in males, females or larvae) were more likely to be located outside of Cf-Inv(1). By combining our findings with genomic scans for environmentally associated SNPs, we were able to pinpoint candidate variants in the inversion that may underlie mechanistic pathways that determine phenotypes. Together the results in this study, combined with previous findings, support the notion that the polymorphic Cf-Inv(1) inversion in this species is a major factor shaping both coding and regulatory variation resulting in highly complex adaptive effects.


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