scholarly journals Androgenesis-Based Doubled Haploidy: Past, Present, and Future Perspectives

2022 ◽  
Vol 12 ◽  
Author(s):  
Brett Hale ◽  
Alison M. R. Ferrie ◽  
Sreekala Chellamma ◽  
J. Pon Samuel ◽  
Gregory C. Phillips
Keyword(s):  
Cell Fate ◽  
Trichostatin A ◽  
Crop Improvement ◽  
Past Research ◽  
Culture Optimization ◽  
Protocol Development ◽  
Doubled Haploidy ◽  
Deacetylase Inhibitor ◽  
Cycle Regulation ◽  
External Stimuli

Androgenesis, which entails cell fate redirection within the microgametophyte, is employed widely for genetic gain in plant breeding programs. Moreover, androgenesis-responsive species provide tractable systems for studying cell cycle regulation, meiotic recombination, and apozygotic embryogenesis within plant cells. Past research on androgenesis has focused on protocol development with emphasis on temperature pretreatments of donor plants or floral buds, and tissue culture optimization because androgenesis has different nutritional requirements than somatic embryogenesis. Protocol development for new species and genotypes within responsive species continues to the present day, but slowly. There is more focus presently on understanding how protocols work in order to extend them to additional genotypes and species. Transcriptomic and epigenetic analyses of induced microspores have revealed some of the cellular and molecular responses required for or associated with androgenesis. For example, microRNAs appear to regulate early microspore responses to external stimuli; trichostatin-A, a histone deacetylase inhibitor, acts as an epigenetic additive; ά-phytosulfokine, a five amino acid sulfated peptide, promotes androgenesis in some species. Additionally, present work on gene transfer and genome editing in microspores suggest that future endeavors will likely incorporate greater precision with the genetic composition of microspores used in doubled haploid breeding, thus likely to realize a greater impact on crop improvement. In this review, we evaluate basic breeding applications of androgenesis, explore the utility of genomics and gene editing technologies for protocol development, and provide considerations to overcome genotype specificity and morphogenic recalcitrance in non-model plant systems.

scholarly journals Epigenetic Induction of Definitive and Pancreatic Endoderm Cell Fate in Human Fibroblasts

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Rangarajan Sambathkumar ◽  
Eric Kalo ◽  
Rob Van Rossom ◽  
Marijke M. Faas ◽  
Paul de Vos ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Fate ◽  
Chromatin Remodeling ◽  
Dna Methyltransferase ◽  
Epigenetic Modification ◽  
Trichostatin A ◽  
Human Fibroblasts ◽  
Marker Genes ◽  
Deacetylase Inhibitor ◽  
Affect Gene Expression

Reprogramming can occur by the introduction of key transcription factors (TFs) as well as by epigenetic changes. We demonstrated that histone deacetylase inhibitor (HDACi) Trichostatin A (TSA) combined with a chromatin remodeling medium (CRM) induced expression of a number of definitive endoderm and early and late pancreatic marker genes. When CRM was omitted, endoderm/pancreatic marker genes were not induced. Furthermore, treatment with DNA methyltransferase inhibitor (DNMTi) 5-azacytidine (5AZA) CRM did not affect gene expression changes, and when 5AZA was combined with TSA, no further increase in gene expression of endoderm, pancreatic endoderm, and endocrine markers was seen over levels induced with TSA alone. Interestingly, TSA-CRM did not affect expression of pluripotency and hepatocyte genes but induced some mesoderm transcripts. Upon removal of TSA-CRM, the endoderm/pancreatic gene expression profile returned to baseline. Our findings underscore the role epigenetic modification in transdifferentiation of one somatic cell into another. However, full reprogramming of fibroblasts to β-cells will require combination of this approach with TF overexpression and/or culture of the partially reprogrammed cells under β-cell specific conditions.

Abstract 3380: Acetylation-dependent Regulation Of Notch1 Signaling In Endothelial Cells

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Virginia Guarani ◽  
Franck Dequiedt ◽  
Andreas M Zeiher ◽  
Stefanie Dimmeler ◽  
Michael Potente
Keyword(s):  
Endothelial Cells ◽  
Notch Signaling ◽  
Cell Fate ◽  
Molecular Mechanisms ◽  
Trichostatin A ◽  
Notch Pathway ◽  
Dependent Manner ◽  
Class Iii ◽  
Cell Fate Decisions ◽  
Knock Down

The Notch signaling pathway is a versatile regulator of cell fate decisions and plays an essential role for embryonic and postnatal vascular development. As only modest differences in Notch pathway activity suffice to determine dramatic differences in blood vessel development, this pathway is tightly regulated by a variety of molecular mechanisms. Reversible acetylation has emerged as an important post-translational modification of several non-histone proteins, which are targeted by histone deacetylases (HDACs). Here, we report that specifically the Notch1 intracellular domain (NICD) is itself an acetylated protein and that its acetylation level is tightly regulated by the SIRT1 deacetylase, which we have previously identified as a key regulator of endothelial angiogenic functions during vascular growth. Coexpression of NICD with histone acetyltransferases such as p300 or PCAF induced a dose- and time-dependent acetylation of NICD. Blocking HDAC activity using the class III HDAC inhibitor nicotinamid (NAM), but not the class I/II HDAC inhibior trichostatin A, resulted in a significant increase of NICD acetylation suggesting that NICD is targetd by class III HDACs for deacetylation. Among the class III HDACs with deacetylase activity (SIRT1, 2, 3, 5), knock down of specifically SIRT1 resulted in enhanced acetylation of NICD. Moreover, wild type SIRT1, but not a catalytically inactive mutant catalyzed the deacetylation of NICD in a nicotinamid-dependent manner. SIRT1, but SIRT2, SIRT3 or SIRT5, associated with NICD through its catalytic domain demonstrating that SIRT1 is a direct NICD deacetylase. Enhancing NICD acetylation by either overexpression of p300 or inhibition of SIRT1 activity using NAM or RNAi-mediated knock down resulted in enhanced NICD protein stability by blocking its ubiquitin-mediated degradation. Consistent with these results, loss of SIRT1 amplified Notch target gene expression in endothelial cells in response to NICD overexpression or treatment with the Notch ligand Dll4. In summary, our results identify reversible acetylation of NICD as a novel molecular mechanism to control Notch signaling and suggest that deacetylation of NICD by SIRT1 plays a key role in the dynamic regulation of Notch signaling in endothelial cells.

scholarly journals Smyd1 Orchestrates Early Heart Development Through Positive and Negative Gene Regulation

2021 ◽  
Vol 9 ◽  
Author(s):  
Zhen Wang ◽  
Robert J. Schwartz ◽  
Jing Liu ◽  
Fei Sun ◽  
Qi Li ◽  
...  
Keyword(s):  
Heart Development ◽  
Striated Muscle ◽  
Trichostatin A ◽  
Structural Defects ◽  
Reporter System ◽  
Cardiac Phenotype ◽  
Deacetylase Inhibitor ◽  
Heart Field ◽  
Polymerase Chain ◽  
Negative Gene

SET and MYND domain-containing protein 1 (Smyd1) is a striated muscle-specific histone methyltransferase. Our previous work demonstrated that deletion of Smyd1 in either cardiomyocytes or the outflow tract (OFT) resulted in embryonic lethality at E9.5, with cardiac structural defects such as truncation of the OFT and right ventricle and impaired expansion and proliferation of the second heart field (SHF). The cardiac phenotype was accompanied by the downregulation of ISL LIM Homeobox 1 (Isl1) and upregulation of atrial natriuretic factor (ANF). However, the mechanisms of Smyd1 regulating Isl1 and ANF during embryonic heart development remain to be elucidated. Here, we employed various biochemical and molecular biological approaches including chromatin immunoprecipitation polymerase chain reaction (ChIP-PCR), pGL3 fluorescence reporter system, and co-immunoprecipitation (CoIP) and found that Smyd1 interacted with absent small homeotic-2-like protein (ASH2L) and activated the promoter of Isl1 by trimethylating H3K4. We also found that Smyd1 associated with HDAC to repress ANF expression using trichostatin A (TSA), a deacetylase inhibitor. In conclusion, Smyd1 participates in early heart development by upregulating the expression of Isl1 and downregulating the expression of ANF.

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