scholarly journals The Hox Gene egl-5 Acts as a Terminal Selector for VD13 Development via Wnt Signaling

2020 ◽  
Vol 8 (1) ◽  
pp. 5
Author(s):  
Meagan Kurland ◽  
Bryn O’Meara ◽  
Dana K. Tucker ◽  
Brian D. Ackley
Keyword(s):  
Transcription Factors ◽  
Wnt Signaling ◽  
Ectopic Expression ◽  
Cell Types ◽  
Loss Of Function ◽  
Cell Specification ◽  
Fluorescent Reporter ◽  
Hox Gene ◽  
Amino Butyric Acid ◽  
Number Of Cells

Nervous systems are comprised of diverse cell types that differ functionally and morphologically. During development, extrinsic signals, e.g., growth factors, can activate intrinsic programs, usually orchestrated by networks of transcription factors. Within that network, transcription factors that drive the specification of features specific to a limited number of cells are often referred to as terminal selectors. While we still have an incomplete view of how individual neurons within organisms become specified, reporters limited to a subset of neurons in a nervous system can facilitate the discovery of cell specification programs. We have identified a fluorescent reporter that labels VD13, the most posterior of the 19 inhibitory GABA (γ-amino butyric acid)-ergic motorneurons, and two additional neurons, LUAL and LUAR. Loss of function in multiple Wnt signaling genes resulted in an incompletely penetrant loss of the marker, selectively in VD13, but not the LUAs, even though other aspects of GABAergic specification in VD13 were normal. The posterior Hox gene, egl-5, was necessary for expression of our marker in VD13, and ectopic expression of egl-5 in more anterior GABAergic neurons induced expression of the marker. These results suggest egl-5 is a terminal selector of VD13, subsequent to GABAergic specification.

scholarly journals A mini review on production of pluripotency factors (Oct4, Sox2, Klf4 and c-Myc) through recombinant protein technology

2020 ◽  
Vol 5 (1) ◽  
pp. 1-4 ◽  
Author(s):  
David Septian Sumanto Marpaung ◽  
Ayu Oshin Yap Sinaga
Keyword(s):  
Stem Cells ◽  
Transcription Factors ◽  
Embryonic Stem Cells ◽  
Pluripotent Stem Cells ◽  
Ectopic Expression ◽  
Embryonic Stem ◽  
Cell Types ◽  
Induced Pluripotency ◽  
Pluripotency Factors ◽  
Induced Pluripotent

The four transcription factors OCT4, SOX2, KLF4 and c-MYC are highly expressed in embryonic stem cells (ESC) and their overexpression can induce pluripotency, the ability to differentiate into all cell types of an organism. The ectopic expression such transcription factors could reprogram somatic stem cells become induced pluripotency stem cells (iPSC), an embryonic stem cells-like. Production of recombinant pluripotency factors gain interests due to high demand from generation of induced pluripotent stem cells in regenerative medical therapy recently. This review will focus on demonstrate the recent advances in recombinant pluripotency factor production using various host.

scholarly journals The Drosophila genes disconnected and disco-related together specify development of adult legs

2016 ◽  
Author(s):  
Juan B. Rosario ◽  
James W. Mahaffey
Keyword(s):  
Transcription Factors ◽  
Gene Network ◽  
Molecular Level ◽  
Ectopic Expression ◽  
Fruit Fly ◽  
Loss Of Function ◽  
Leg Development ◽  
Body Patterning ◽  
Development Trajectory ◽  
Wing Discs

ABSTRACTIn the fruit fly, Drosophila melanogaster, specification of the legs begins during embryogenesis when Wingless signaling induces small groups of cells to form the imaginal disc primordia in the thoracic segments. This signal initiates expression of transcription factors that will later be used to pattern the legs. The paralogous genes disconnected and disco-related encode transcription factors that are expressed in the disc primordia during early embryogenesis, and their expression continues in the leg discs during larval and pupal stages. The importance of these two genes in establishing the leg development trajectory was indicated by our previous observation that ectopic expression of either gene in the wing discs cells caused legs to develop in place of wings. However, because of their redundancy and requirement for survival during embryogenesis, we were unable to define their role in development of the adult legs. Here, we report loss-of-function analyses of the disco genes during development of the legs. We discovered that loss of both genes’ functions causes both truncation of the distal leg with apparent overgrowth of proximal regions and complete loss of legs and ventral thoracic body patterning. At the molecular level we noted reduction or loss of signaling and transcription factors that pattern the proximal-distal axis of the legs. We conclude from these studies that the disco genes promote leg development through regulation of signaling processes, but also by stabilizing expression of the leg determination gene network.

Patterning of dopaminergic neurotransmitter identity among Caenorhabditis elegans ray sensory neurons by a TGFbeta family signaling pathway and a Hox gene

Development ◽  
1999 ◽  
Vol 126 (24) ◽  
pp. 5819-5831 ◽  
Author(s):  
R. Lints ◽  
S.W. Emmons
Keyword(s):  
Caenorhabditis Elegans ◽  
Heat Shock ◽  
Signaling Pathway ◽  
Cell Fate ◽  
Sensory Neurons ◽  
Ectopic Expression ◽  
Temperature Shift ◽  
Temperature Sensitive ◽  
Loss Of Function ◽  
Hox Gene

We have investigated the mechanism that patterns dopamine expression among Caenorhabditis elegans male ray sensory neurons. Dopamine is expressed by the A-type sensory neurons in three out of the nine pairs of rays. We used expression of a tyrosine hydroxylase reporter transgene as well as direct assays for dopamine to study the genetic requirements for adoption of the dopaminergic cell fate. In loss-of-function mutants affecting a TGFbeta family signaling pathway, the DBL-1 pathway, dopaminergic identity is adopted irregularly by a wider subset of the rays. Ectopic expression of the pathway ligand, DBL-1, from a heat-shock-driven transgene results in adoption of dopaminergic identity by rays 3–9; rays 1 and 2 are refractory. The rays are therefore prepatterned with respect to their competence to be induced by a DBL-1 pathway signal. Temperature-shift experiments with a temperature-sensitive type II receptor mutant, as well as heat-shock induction experiments, show that the DBL-1 pathway acts during an interval that extends from two to one cell generation before ray neurons are born and begin to differentiate. In a mutant of the AbdominalB class Hox gene egl-5, rays that normally express EGL-5 do not adopt dopaminergic fate and cannot be induced to express DA when DBL-1 is provided by a heat-shock-driven dbl-1 transgene. Therefore, egl-5 is required for making a subset of rays capable of adopting dopaminergic identity, while the function of the DBL-1 pathway signal is to pattern the realization of this capability.

scholarly journals A functional genomics screen identifying blood cell development genes in Drosophila by undergraduates participating in a course-based research experience

2021 ◽  
Vol 11 (1) ◽  
pp. 1-23
Author(s):  
Cory J Evans ◽  
John M Olson ◽  
Bama Charan Mondal ◽  
Pratyush Kandimalla ◽  
Ariano Abbasi ◽  
...  
Keyword(s):  
Blood Cell ◽  
Functional Genomics ◽  
Undergraduate Students ◽  
Undergraduate Research ◽  
Cell Types ◽  
Bioinformatic Analysis ◽  
Research Experience ◽  
Loss Of Function ◽  
Fluorescent Reporter ◽  
Stem Retention

Abstract Undergraduate students participating in the UCLA Undergraduate Research Consortium for Functional Genomics (URCFG) have conducted a two-phased screen using RNA interference (RNAi) in combination with fluorescent reporter proteins to identify genes important for hematopoiesis in Drosophila. This screen disrupted the function of approximately 3500 genes and identified 137 candidate genes for which loss of function leads to observable changes in the hematopoietic development. Targeting RNAi to maturing, progenitor, and regulatory cell types identified key subsets that either limit or promote blood cell maturation. Bioinformatic analysis reveals gene enrichment in several previously uncharacterized areas, including RNA processing and export and vesicular trafficking. Lastly, the participation of students in this course-based undergraduate research experience (CURE) correlated with increased learning gains across several areas, as well as increased STEM retention, indicating that authentic, student-driven research in the form of a CURE represents an impactful and enriching pedagogical approach.

scholarly journals Identification ofkit-ligand aas the Gene Responsible for the Medaka Pigment Cell Mutantfew melanophore

2019 ◽  
Author(s):  
Yuji Otsuki ◽  
Yuki Okuda ◽  
Kiyoshi Naruse ◽  
Hideyuki Saya
Keyword(s):  
Transcription Factors ◽  
Pigment Cell ◽  
Cell Types ◽  
The Body ◽  
Pigment Cells ◽  
Cell Specification ◽  
Kit Ligand ◽  
Body Coloration ◽  
Insight Into ◽  
Pigmentation Disorders

ABSTRACTThe body coloration of animals is due to pigment cells derived from neural crest cells, which are multipotent and differentiate into diverse cell types. Medaka (Oryzias latipes) possesses four distinct types of pigment cells known as melanophores, xanthophores, iridophores, and leucophores. Thefew melanophore(fm) mutant of medaka is characterized by reduced numbers of melanophores and leucophores. We here identifykit-ligand a(kitlga) as the gene whose mutation gives rise to thefmphenotype. This identification was confirmed by generation ofkitlgaknockout medaka and the findings that these fish also manifest reduced numbers of melanophores and leucophores and fail to rescue thefmmutant phenotype. We also found that expression ofsox5,pax7a,pax3a, andmitfagenes is down-regulated in bothfmandkitlgaknockout medaka, implicating c-Kit signaling in regulation of the expression of these genes as well as the encoded transcription factors in pigment cell specification. Our results may provide insight into the pathogenesis of c-Kit–related pigmentation disorders such as piebaldism in humans, and ourkitlgaknockout medaka may prove useful as a tool for drug screening.

scholarly journals Wnt Signaling Drives Ectopic Gene Expression and Larval Arrest in the Absence of the Caenorhabditis elegans DREAM Repressor Complex

2019 ◽  
Vol 10 (2) ◽  
pp. 863-874
Author(s):  
Jerrin R. Cherian ◽  
Katherine V. Adams ◽  
Lisa N. Petrella
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Caenorhabditis Elegans ◽  
Wnt Signaling ◽  
Somatic Cells ◽  
Ectopic Expression ◽  
Complete Suppression ◽  
Knock Down ◽  
Link Type ◽  
Germline Genes

Establishment and maintenance of proper gene expression is a requirement for normal growth and development. The DREAM complex in Caenorhabditis elegans functions as a transcriptional repressor of germline genes in somatic cells. At 26°, DREAM complex mutants show increased misexpression of germline genes in somatic cells and High Temperature Arrest (HTA) of worms at the first larval stage. To identify transcription factors required for the ectopic expression of germline genes in DREAM complex mutants, we conducted an RNA interference screen against 123 transcription factors capable of binding DREAM target promoter loci for suppression of the HTA phenotype in lin-54 mutants. We found that knock-down of 15 embryonically expressed transcription factors suppress the HTA phenotype in lin-54 mutants. Five of the transcription factors found in the initial screen have associations with Wnt signaling pathways. In a subsequent RNAi suppression screen of Wnt signaling factors we found that knock-down of the non-canonical Wnt/PCP pathway factors vang-1, prkl-1 and fmi-1 in a lin-54 mutant background resulted in strong suppression of the HTA phenotype. Animals mutant for both lin-54 and vang-1 showed almost complete suppression of the HTA phenotype, pgl-1 misexpression, and fertility defects associated with lin-54 single mutants at 26°. We propose a model whereby a set of embryonically expressed transcription factors, and the Wnt/PCP pathway, act opportunistically to activate DREAM complex target genes in somatic cells of DREAM complex mutants at 26°.

scholarly journals Wnt signaling activates gene expression in the absence of the C. elegans DREAM repressor complex in somatic cells

2019 ◽  
Author(s):  
Jerrin R. Cherian ◽  
Lisa N. Petrella
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Wnt Signaling ◽  
Target Genes ◽  
Somatic Cells ◽  
Ectopic Expression ◽  
Normal Growth ◽  
Complete Suppression ◽  
Strong Suppression ◽  
Germline Genes

ABSTRACTEstablishment and maintenance of proper gene expression is a requirement for normal growth and development. The DREAM complex in Caenorhabditis elegans functions as a transcriptional repressor of germline genes in somatic cells. At 26°C, DREAM complex mutants show temperature associated increase in misexpression of germline genes in somatic cells and High Temperature Arrest (HTA) of worms at the first larval stage. To identify transcription factors required for the ectopic expression of germline genes in DREAM complex mutants, we conducted an RNA interference screen against 123 transcription factors capable of binding DREAM target promoter loci for suppression of the HTA phenotype in lin-54 mutants. We found 15 embryonically expressed transcription factors that suppress the HTA phenotype in lin-54 mutants. Five of the transcription factors found in the initial screen interact with the Wnt signaling pathways. In a subsequent RNAi suppression screen of Wnt signaling factors we found that knock-down of the non-canonical Wnt/PCP pathway factors vang-1, prkl-1 and fmi-1 in lin-54 mutant background resulted in strong suppression of the HTA phenotype. Animals mutant for both lin-54 and vang-1 showed almost complete suppression of the HTA phenotype, pgl-1 misexpression, and fertility defects associated with lin-54 single mutants at 26°C. We propose a model whereby a set of embryonically expressed transcription factors, and the Wnt/PCP pathway, act opportunistically to activate DREAM complex target genes in somatic cells of DREAM complex mutants at 26°C.

scholarly journals Two transcription factors, Pou4f2 and Isl1, are sufficient to specify the retinal ganglion cell fate

2015 ◽  
Vol 112 (13) ◽  
pp. E1559-E1568 ◽  
Author(s):  
Fuguo Wu ◽  
Tadeusz J. Kaczynski ◽  
Santhosh Sethuramanujam ◽  
Renzhong Li ◽  
Varsha Jain ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Cell Fate ◽  
Ganglion Cells ◽  
Ectopic Expression ◽  
Cell Types ◽  
Retinal Cell ◽  
Retinal Ganglion ◽  
Pou Domain ◽  
Gene Enhancer ◽  
Gene Regulatory

As with other retinal cell types, retinal ganglion cells (RGCs) arise from multipotent retinal progenitor cells (RPCs), and their formation is regulated by a hierarchical gene-regulatory network (GRN). Within this GRN, three transcription factors—atonal homolog 7 (Atoh7), POU domain, class 4, transcription factor 2 (Pou4f2), and insulin gene enhancer protein 1 (Isl1)—occupy key node positions at two different stages of RGC development. Atoh7 is upstream and is required for RPCs to gain competence for an RGC fate, whereas Pou4f2 and Isl1 are downstream and regulate RGC differentiation. However, the genetic and molecular basis for the specification of the RGC fate, a key step in RGC development, remains unclear. Here we report that ectopic expression of Pou4f2 and Isl1 in the Atoh7-null retina using a binary knockin-transgenic system is sufficient for the specification of the RGC fate. The RGCs thus formed are largely normal in gene expression, survive to postnatal stages, and are physiologically functional. Our results indicate that Pou4f2 and Isl1 compose a minimally sufficient regulatory core for the RGC fate. We further conclude that during development a core group of limited transcription factors, including Pou4f2 and Isl1, function downstream of Atoh7 to determine the RGC fate and initiate RGC differentiation.

Maize unstable factor for orange1 is essential for endosperm development and carbohydrate accumulation

2021 ◽  
Author(s):  
Debamalya Chatterjee ◽  
Kameron Wittmeyer ◽  
Tzuu-fen Lee ◽  
Jin Cui ◽  
Neela H Yennawar ◽  
...  
Keyword(s):  
Expression Patterns ◽  
Ectopic Expression ◽  
Cell Types ◽  
Endosperm Development ◽  
Adjacent Cell ◽  
Specific Gene ◽  
Loss Of Function ◽  
Wall Ingrowth ◽  
Wide Range ◽  
The Impact

Abstract Maize (Zea mays L.) Ufo1-1 is a spontaneous dominant mutation of the unstable factor for orange1 (ufo1). We recently cloned ufo1, which is a Poaceae specific gene expressed solely during seed development in maize. Here we have characterized Ufo1-1 and a loss-of-function Ds insertion allele (ufo1-Dsg) to decipher the role of ufo1 in maize. We found that both ufo1 mutant alleles impact sugars and hormones, and have defects in the basal endosperm transfer layer (BETL) and adjacent cell types. The Ufo1-1 BETL had reduced cell elongation and cell wall ingrowth, resulting in cuboidal shaped transfer cells. In contrast, the ufo1-Dsg BETL cells showed a reduced overall size with abnormal wall ingrowth. Expression analysis identified the impact of ufo1 on several genes essential for BETL development. The overexpression of Ufo1-1 in various tissues leads to ectopic phenotypes, including abnormal cell organization and stomata subsidiary cell defects. Interestingly, pericarp and leaf transcriptomes also showed that as compared to wild type, Ufo1-1 had ectopic expression of endosperm development-specific genes. This study shows that Ufo1-1 impacts the expression patterns of a wide range of genes involved in various developmental processes.

par-4, a gene required for cytoplasmic localization and determination of specific cell types in Caenorhabditis elegans embryogenesis.

Genetics ◽  
1992 ◽  
Vol 130 (4) ◽  
pp. 771-790 ◽  
Author(s):  
D G Morton ◽  
J M Roos ◽  
K J Kemphues
Keyword(s):  
Caenorhabditis Elegans ◽  
Cell Types ◽  
Intestinal Cells ◽  
Specific Cell ◽  
Cytoplasmic Localization ◽  
Loss Of Function ◽  
Embryo Viability ◽  
Cell Stage ◽  
Maternal Genome

Abstract Specification of some cell fates in the early Caenorhabditis elegans embryo is mediated by cytoplasmic localization under control of the maternal genome. Using nine newly isolated mutations, and two existing mutations, we have analyzed the role of the maternally expressed gene par-4 in cytoplasmic localization. We recovered seven new par-4 alleles in screens for maternal effect lethal mutations that result in failure to differentiate intestinal cells. Two additional par-4 mutations were identified in noncomplementation screens using strains with a high frequency of transposon mobility. All 11 mutations cause defects early in development of embryos produced by homozygous mutant mothers. Analysis with a deficiency in the region indicates that it33 is a strong loss-of-function mutation. par-4(it33) terminal stage embryos contain many cells, but show no morphogenesis, and are lacking intestinal cells. Temperature shifts with the it57ts allele suggest that the critical period for both intestinal differentiation and embryo viability begins during oogenesis, about 1.5 hr before fertilization, and ends before the four-cell stage. We propose that the primary function of the par-4 gene is to act as part of a maternally encoded system for cytoplasmic localization in the first cell cycle, with par-4 playing a particularly important role in the determination of intestine. Analysis of a par-4; par-2 double mutant suggests that par-4 and par-2 gene products interact in this system.

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