scholarly journals Krüppel-like factor gene function in the ctenophore Mnemiopsis leidyi assessed by CRISPR/Cas9-mediated genome editing

2019 ◽  
Author(s):  
Jason S Presnell ◽  
William E Browne

AbstractThe Krüppel-like factor (Klf) gene family encodes for transcription factors that play an important role in the regulation of stem cell proliferation, cell differentiation, and development in bilaterians. While Klf genes have been shown to be expressed in various cell types in non-bilaterian animals, their functional role in early diverging animal lineages has not been assessed. Thus, the ancestral activity of these transcription factors in animal development is not well understood. The ctenophore Mnemiopsis leidyi has emerged as an important non-bilaterian model system for understanding early animal evolution. Here we characterize the expression and functional role of Klf genes during M. leidyi embryogenesis. Zygotic Klf gene function was assessed with both CRISPR/Cas9-mediated genome editing knockout and splice-blocking morpholino oligonucleotide knockdown approaches. Abrogation of zygotic Klf expression during M. leidyi embryogenesis results in the irregular development of several organs including the pharynx, tentacle bulbs, and apical organ. Our data suggest an ancient role for Klf genes in regulating endodermal patterning.Summary StatementUsing morpholino oligonucleotide knockdown and CRISPR/Cas9 genome editing, this study shows that in the ctenophore Mnemiopsis leidyi, tissues derived from the endoderm are dependent upon Klf5 ortholog expression for proper development and patterning.

Development ◽  
2021 ◽  
Author(s):  
Jason S. Presnell ◽  
William E. Browne

The Krüppel-like factor (Klf) gene family encodes for transcription factors that play an important role in the regulation of stem cell proliferation, cell differentiation, and development in bilaterians. While Klf genes have been shown to functionally specify various cell types in non-bilaterian animals, their role in early diverging animal lineages has not been assessed. Thus, the ancestral activity of these transcription factors in animal development is not well understood. The ctenophore Mnemiopsis leidyi has emerged as an important non-bilaterian model system for understanding early animal evolution. Here we characterize the expression and functional role of Klf genes during M. leidyi embryogenesis. Zygotic Klf gene function was assessed with both CRISPR/Cas9-mediated genome editing and splice-blocking morpholino oligonucleotide knockdown approaches. Abrogation of zygotic Klf expression during M. leidyi embryogenesis results in abnormal development of several organs including the pharynx, tentacle bulbs, and apical organ. Our data suggest an ancient role for Klf genes in regulating endodermal patterning, possibly through regulation of cell proliferation.


2017 ◽  
Vol 114 (23) ◽  
pp. 5878-5885 ◽  
Author(s):  
Hernando Martínez Vergara ◽  
Paola Yanina Bertucci ◽  
Peter Hantz ◽  
Maria Antonietta Tosches ◽  
Kaia Achim ◽  
...  

The comparative study of cell types is a powerful approach toward deciphering animal evolution. To avoid selection biases, however, comparisons ideally involve all cell types present in a multicellular organism. Here, we use image registration and a newly developed “Profiling by Signal Probability Mapping” algorithm to generate a cellular resolution 3D expression atlas for an entire animal. We investigate three-segmented young worms of the marine annelid Platynereis dumerilii, with a rich diversity of differentiated cells present in relatively low number. Starting from whole-mount expression images for close to 100 neural specification and differentiation genes, our atlas identifies and molecularly characterizes 605 bilateral pairs of neurons at specific locations in the ventral nerve cord. Among these pairs, we identify sets of neurons expressing similar combinations of transcription factors, located at spatially coherent anterior-posterior, dorsal-ventral, and medial-lateral coordinates that we interpret as cell types. Comparison with motor and interneuron types in the vertebrate neural tube indicates conserved combinations, for example, of cell types cospecified by Gata1/2/3 and Tal transcription factors. These include V2b interneurons and the central spinal fluid-contacting Kolmer-Agduhr cells in the vertebrates, and several neuron types in the intermediate ventral ganglionic mass in the annelid. We propose that Kolmer-Agduhr cell-like mechanosensory neurons formed part of the mucociliary sole in protostome-deuterostome ancestors and diversified independently into several neuron types in annelid and vertebrate descendants.


Development ◽  
2020 ◽  
Vol 147 (19) ◽  
pp. dev161430
Author(s):  
Albert Tsai ◽  
Rafael Galupa ◽  
Justin Crocker

ABSTRACTDevelopmental enhancers drive gene expression in specific cell types during animal development. They integrate signals from many different sources mediated through the binding of transcription factors, producing specific responses in gene expression. Transcription factors often bind low-affinity sequences for only short durations. How brief, low-affinity interactions drive efficient transcription and robust gene expression is a central question in developmental biology. Localized high concentrations of transcription factors have been suggested as a possible mechanism by which to use these enhancer sites effectively. Here, we discuss the evidence for such transcriptional microenvironments, mechanisms for their formation and the biological consequences of such sub-nuclear compartmentalization for developmental decisions and evolution.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Stephan Hailfinger ◽  
Klaus Schulze-Osthoff

Abstract Psoriasis is a frequent autoimmune-related skin disease, which involves various cell types such as T cells, keratinocytes and dendritic cells. Genetic variations, such as mutations of CARD14, can promote the development of the disease. CARD14 mutations as well as the stimulation of immune and cytokine receptors activate the paracaspase MALT1, a potent activator of the transcription factors NF-κB and AP-1. The disease-promoting role of MALT1 for psoriasis is mediated by both its protease activity as well as its molecular scaffold function. Here, we review the importance of MALT1-mediated signaling and its therapeutic implications in psoriasis.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Gilor Kelly ◽  
Danja Brandsma ◽  
Aiman Egbaria ◽  
Ofer Stein ◽  
Adi Doron-Faigenboim ◽  
...  

AbstractThe hypocotyls of germinating seedlings elongate in a search for light to enable autotrophic sugar production. Upon exposure to light, photoreceptors that are activated by blue and red light halt elongation by preventing the degradation of the hypocotyl-elongation inhibitor HY5 and by inhibiting the activity of the elongation-promoting transcription factors PIFs. The question of how sugar affects hypocotyl elongation and which cell types stimulate and stop that elongation remains unresolved. We found that overexpression of a sugar sensor, Arabidopsis hexokinase 1 (HXK1), in guard cells promotes hypocotyl elongation under white and blue light through PIF4. Furthermore, expression of PIF4 in guard cells is sufficient to promote hypocotyl elongation in the light, while expression of HY5 in guard cells is sufficient to inhibit the elongation of the hy5 mutant and the elongation stimulated by HXK1. HY5 exits the guard cells and inhibits hypocotyl elongation, but is degraded in the dark. We also show that the inhibition of hypocotyl elongation by guard cells’ HY5 involves auto-activation of HY5 expression in other tissues. It appears that guard cells are capable of coordinating hypocotyl elongation and that sugar and HXK1 have the opposite effect of light on hypocotyl elongation, converging at PIF4.


Blood ◽  
1999 ◽  
Vol 94 (12) ◽  
pp. 4060-4066 ◽  
Author(s):  
Maria Fiammetta Romano ◽  
Annalisa Lamberti ◽  
Rita Bisogni ◽  
Corrado Garbi ◽  
Antonio M. Pagnano ◽  
...  

Abstract We investigated the involvement of NF-κB/Rel transcription factors that reportedly can inhibit apoptosis in various cell types in the antiapoptotic mechanism of the cytoprotectant amifostine. In the nontumorigenic murine myeloid progenitor 32D cells incubated with amifostine, we detected a reduction of the IκB cytoplasmic levels by Western blotting and a raising of nuclear NF-κB/Rel complexes by electrophoretic mobility shift assay. Amifostine inhibited by more than 30% the growth factor deprivation-induced apoptosis, whereas its effect failed when we blocked the NF-κB/Rel activity with an NF-κB/Rel-binding phosphorothioate decoy oligodeoxynucleotide. In human cord blood CD34+ cells, the NF-κB/Rel p65 subunit was detectable (using immunofluorescence analysis) mainly in the cytoplasm in the absence of amifostine, whereas its presence was appreciable in the nuclei of cells incubated with the cytoprotectant. In 4 CD34+ samples incubated for 3 days in cytokine-deficient conditions, cell apoptosis was reduced by more than 30% in the presence of amifostine (or amifostine plus a control oligo); the effect of amifostine was abolished in cultures with the decoy oligo. These findings indicate that the inhibition of hematopoietic progenitor cell apoptosis by amifostine requires the induction of NF-κB/Rel factors and that the latter can therefore exert an antiapoptotic activity in the hematopoietic progenitor cell compartment. Furthermore, the identification of this specific mechanism underlying the survival-promoting activity of amifostine lends support to the possible use of this agent in apoptosis-related pathologies, such as myelodysplasias.


Development ◽  
1994 ◽  
Vol 120 (4) ◽  
pp. 957-971 ◽  
Author(s):  
M. Goulding ◽  
A. Lumsden ◽  
A.J. Paquette

The segmented mesoderm in vertebrates gives rise to a variety of cell types in the embryo including the axial skeleton and muscle. A number of transcription factors containing a paired domain (Pax proteins) are expressed in the segmented mesoderm during embryogenesis. These include Pax-3 and a closely related gene, Pax-7, both of which are expressed in the segmental plate and in the dermomyotome. In this paper, we show that signals from the notochord pattern the expression of Pax-3, Pax-7 and Pax-9 in somites and the subsequent differentiation of cell types that arise from the somitic mesoderm. We directly assess the role of the Pax-3 gene in the differentiation of cell types derived from the dermomyotome by analyzing the development of muscle in splotch mouse embryos which lack a functional Pax-3 gene. A population of Pax-3-expressing cells derived from the dermomyotome that normally migrate into the limb are absent in homozygous splotch embryos and, as a result, limb muscles are lost. No abnormalities were detected in the trunk musculature of splotch embryos indicating that Pax-3 is necessary for the development of the limb but not trunk muscle.


2015 ◽  
Vol 1 (7) ◽  
pp. e1500454 ◽  
Author(s):  
Xin Han ◽  
Zongbin Liu ◽  
Myeong chan Jo ◽  
Kai Zhang ◽  
Ying Li ◽  
...  

The CRISPR (clustered regularly interspaced short palindromic repeats)–Cas (CRISPR-associated) nuclease system represents an efficient tool for genome editing and gene function analysis. It consists of two components: single-guide RNA (sgRNA) and the enzyme Cas9. Typical sgRNA and Cas9 intracellular delivery techniques are limited by their reliance on cell type and exogenous materials as well as their toxic effects on cells (for example, electroporation). We introduce and optimize a microfluidic membrane deformation method to deliver sgRNA and Cas9 into different cell types and achieve successful genome editing. This approach uses rapid cell mechanical deformation to generate transient membrane holes to enable delivery of biomaterials in the medium. We achieved high delivery efficiency of different macromolecules into different cell types, including hard-to-transfect lymphoma cells and embryonic stem cells, while maintaining high cell viability. With the advantages of broad applicability across different cell types, particularly hard-to-transfect cells, and flexibility of application, this method could potentially enable new avenues of biomedical research and gene targeting therapy such as mutation correction of disease genes through combination of the CRISPR-Cas9–mediated knockin system.


2020 ◽  
Author(s):  
Feng Tian ◽  
Fan Zhou ◽  
Xiang Li ◽  
Wenping Ma ◽  
Honggui Wu ◽  
...  

SummaryBy circumventing cellular heterogeneity, single cell omics have now been widely utilized for cell typing in human tissues, culminating with the undertaking of human cell atlas aimed at characterizing all human cell types. However, more important are the probing of gene regulatory networks, underlying chromatin architecture and critical transcription factors for each cell type. Here we report the Genomic Architecture of Cells in Tissues (GeACT), a comprehensive genomic data base that collectively address the above needs with the goal of understanding the functional genome in action. GeACT was made possible by our novel single-cell RNA-seq (MALBAC-DT) and ATAC-seq (METATAC) methods of high detectability and precision. We exemplified GeACT by first studying representative organs in human mid-gestation fetus. In particular, correlated gene modules (CGMs) are observed and found to be cell-type-dependent. We linked gene expression profiles to the underlying chromatin states, and found the key transcription factors for representative CGMs.HighlightsGenomic Architecture of Cells in Tissues (GeACT) data for human mid-gestation fetusDetermining correlated gene modules (CGMs) in different cell types by MALBAC-DTMeasuring chromatin open regions in single cells with high detectability by METATACIntegrating transcriptomics and chromatin accessibility to reveal key TFs for a CGM


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Alexander J Tarashansky ◽  
Jacob M Musser ◽  
Margarita Khariton ◽  
Pengyang Li ◽  
Detlev Arendt ◽  
...  

Comparing single-cell transcriptomic atlases from diverse organisms can elucidate the origins of cellular diversity and assist the annotation of new cell atlases. Yet, comparison between distant relatives is hindered by complex gene histories and diversifications in expression programs. Previously, we introduced the self-assembling manifold (SAM) algorithm to robustly reconstruct manifolds from single-cell data (Tarashansky et al., 2019). Here, we build on SAM to map cell atlas manifolds across species. This new method, SAMap, identifies homologous cell types with shared expression programs across distant species within phyla, even in complex examples where homologous tissues emerge from distinct germ layers. SAMap also finds many genes with more similar expression to their paralogs than their orthologs, suggesting paralog substitution may be more common in evolution than previously appreciated. Lastly, comparing species across animal phyla, spanning mouse to sponge, reveals ancient contractile and stem cell families, which may have arisen early in animal evolution.


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