Conditional Expression Synthesis with Face Parsing Transformation

Key Points B-cell–specific expression of Myd88p.L252P leads to the development of DLBCL in mice. The Myd88p.L252P mutation cooperates with BCL2 amplifications in ABC-DLBCL lymphomagenesis in vivo.

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Drosophila Notch receptor activity suppresses Hairless function during adult external sensory organ development.

Genetics ◽

10.1093/genetics/141.4.1491 ◽

1995 ◽

Vol 141 (4) ◽

pp. 1491-1505

Author(s):

D F Lyman ◽

B Yedvobnick

Keyword(s):

Cell Fate ◽

Daughter Cell ◽

Notch Receptor ◽

Sensory Organ ◽

Cell Fates ◽

Gain Of Function ◽

Over Expression ◽

Cell Fate Decisions ◽

Synergistic Enhancement ◽

Conditional Expression

Abstract The neurogenic Notch locus of Drosophila encodes a receptor necessary for cell fate decisions within equivalence groups, such as proneural clusters. Specification of alternate fates within clusters results from inhibitory communication among cells having comparable neural fate potential. Genetically, Hairless (H) acts as an antagonist of most neurogenic genes and may insulate neural precursor cells from inhibition. H function is required for commitment to the bristle sensory organ precursor (SOP) cell fate and for daughter cell fates. Using Notch gain-of-function alleles and conditional expression of an activated Notch transgene, we show that enhanced signaling produces H-like loss-of-function phenotypes by suppressing bristle SOP cell specification or by causing an H-like transformation of sensillum daughter cell fates. Furthermore, adults carrying Notch gain of function and H alleles exhibit synergistic enhancement of mutant phenotypes. Over-expression of an H+ transgene product suppressed virtually all phenotypes generated by Notch gain-of-function genotypes. Phenotypes resulting from over-expression of the H+ transgene were blocked by the Notch gain-of-function products, indicating a balance between Notch and H activity. The results suggest that H insulates SOP cells from inhibition and indicate that H activity is suppressed by Notch signaling.

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The CRISPR/Cas9 Minipig—A Transgenic Minipig to Produce Specific Mutations in Designated Tissues

Cancers ◽

10.3390/cancers13123024 ◽

2021 ◽

Vol 13 (12) ◽

pp. 3024

Author(s):

Martin Fogtmann Berthelsen ◽

Maria Riedel ◽

Huiqiang Cai ◽

Søren H. Skaarup ◽

Aage K. O. Alstrup ◽

...

Keyword(s):

Fluorescent Protein ◽

Yellow Fluorescent Protein ◽

Somatic Cells ◽

Genetic Alterations ◽

Lung Epithelial Cells ◽

Target Cells ◽

Multiple Gene ◽

Conditional Expression ◽

Gene Alterations

The generation of large transgenic animals is impeded by complex cloning, long maturation and gastrulation times. An introduction of multiple gene alterations increases the complexity. We have cloned a transgenic Cas9 minipig to introduce multiple mutations by CRISPR in somatic cells. Transgenic Cas9 pigs were generated by somatic cell nuclear transfer and were backcrossed to Göttingen Minipigs for two generations. Cas9 expression was controlled by FlpO-mediated recombination and was visualized by translation from red to yellow fluorescent protein. In vitro analyses in primary fibroblasts, keratinocytes and lung epithelial cells confirmed the genetic alterations executed by the viral delivery of single guide RNAs (sgRNA) to the target cells. Moreover, multiple gene alterations could be introduced simultaneously in a cell by viral delivery of sgRNAs. Cells with loss of TP53, PTEN and gain-of-function mutation in KRASG12D showed increased proliferation, confirming a transformation of the primary cells. An in vivo activation of Cas9 expression could be induced by viral delivery to the skin. Overall, we have generated a minipig with conditional expression of Cas9, where multiple gene alterations can be introduced to somatic cells by viral delivery of sgRNA. The development of a transgenic Cas9 minipig facilitates the creation of complex pre-clinical models for cancer research.

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Sustained Inhibition of HIV-1 Replication by Conditional Expression of theE. coli-Derived Endoribonuclease MazF in CD4+T cells

Human Gene Therapy Methods ◽

10.1089/hgtb.2012.131 ◽

2013 ◽

Vol 24 (2) ◽

pp. 94-103 ◽

Cited By ~ 11

Author(s):

Mika Okamoto ◽

Hideto Chono ◽

Yasuhiro Kawano ◽

Naoki Saito ◽

Hiroshi Tsuda ◽

...

Keyword(s):

T Cells ◽

Cd4 T Cells ◽

Conditional Expression ◽

Hiv 1 ◽

Sustained Inhibition

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Conditional expression of the FTO gene product in rat INS-1 cells reveals its rapid turnover and a role in the profile of glucose-induced insulin secretion

Clinical Science ◽

10.1042/cs20100416 ◽

2011 ◽

Vol 120 (9) ◽

pp. 403-413 ◽

Cited By ~ 15

Author(s):

Mark A. Russell ◽

Noel G. Morgan

Keyword(s):

Insulin Secretion ◽

Expression System ◽

Proteasome Inhibitors ◽

Inducible Promoter ◽

Insulin Biosynthesis ◽

Second Phase ◽

Β Cells ◽

Pancreatic Β Cells ◽

Peripheral Tissues ◽

Conditional Expression

Common polymorphisms within the FTO (fat mass and obesity-associated) gene correlate with increased BMI (body mass index) and a rising risk of Type 2 diabetes. FTO is highly expressed in the brain but has also been detected in peripheral tissues, including the endocrine pancreas, although its function there is unclear. The aim of the present study was to investigate the role of FTO protein in pancreatic β-cells using a conditional expression system developed in INS-1 cells. INS-1 cells were stably transfected with FTO–HA (haemagluttinin) incorporated under the control of a tetracycline-inducible promoter. Induction of FTO protein resulted in localization of the tagged protein to the nucleus. The level of FTO–HA protein achieved in transfected cells was tightly regulated, and experiments with selective inhibitors revealed that FTO–HA is rapidly degraded via the ubiquitin/proteasome pathway. The nuclear localization was not altered by proteasome inhibitors, although following treatment with PYR-41, an inhibitor of ubiquitination, some of the protein adopted a perinuclear localization. Unexpectedly, modestly increased expression of FTO–HA selectively enhanced the first phase of insulin secretion when INS-1 monolayers or pseudoislets were stimulated with 20 mM glucose, whereas the second phase remained unchanged. The mechanism responsible for the potentiation of glucose-induced insulin secretion is unclear; however, further experiments revealed that it did not involve an increase in insulin biosynthesis or any changes in STAT3 (signal transducer and activator of transcription 3) expression. Taken together, these results suggest that the FTO protein may play a hitherto unrecognized role in the control of first-phase insulin secretion in pancreatic β-cells.

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Downregulation of c-Jun Expression by Transcription Factor C/EBPα Is Critical for Granulocytic Lineage Commitment

Molecular and Cellular Biology ◽

10.1128/mcb.22.24.8681-8694.2002 ◽

2002 ◽

Vol 22 (24) ◽

pp. 8681-8694 ◽

Cited By ~ 40

Author(s):

Janki Rangatia ◽

Rajani Kanth Vangala ◽

Nicolai Treiber ◽

Pu Zhang ◽

Hanna Radomska ◽

...

Keyword(s):

Transcription Factor ◽

Knockout Mouse ◽

Leucine Zipper ◽

Fetal Liver ◽

Mrna Level ◽

Monocytic Differentiation ◽

Granulocytic Differentiation ◽

Conditional Expression ◽

Factor C ◽

Transcription Factor Complex

ABSTRACT The transcription factor C/EBPα is crucial for the differentiation of granulocytes. Conditional expression of C/EBPα triggers neutrophilic differentiation, and C/EBPα can block 12-O-tetradecanoylphorbol-13-acetate-induced monocytic differentiation of bipotential myeloid cells. In C/EBPα knockout mice, no mature granulocytes are present. A dramatic increase of c-Jun mRNA in C/EBPα knockout mouse fetal liver was observed. c-Jun, a component of the AP-1 transcription factor complex and a coactivator of the transcription factor PU.1, is important for monocytic differentiation. Here we report that C/EBPα downregulates c-Jun expression to drive granulocytic differentiation. An ectopic increase of C/EBPα expression decreases the c-Jun mRNA level, and the human c-Jun promoter activity is downregulated eightfold in the presence of C/EBPα. C/EBPα and c-Jun interact through their leucine zipper domains, and this interaction prevents c-Jun from binding to DNA. This results in downregulation of c-Jun's capacity to autoregulate its own promoter through the proximal AP-1 site. Overexpression of c-Jun prevents C/EBPα-induced granulocytic differentiation. Thus, we propose a model in which C/EBPα needs to downregulate c-Jun expression and transactivation capacity for promoting granulocytic differentiation.

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Activating mutations in BRAF disrupt the hypothalamo-pituitary axis leading to hypopituitarism in mice and humans

Nature Communications ◽

10.1038/s41467-021-21712-4 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Angelica Gualtieri ◽

Nikolina Kyprianou ◽

Louise C. Gregory ◽

Maria Lillina Vignola ◽

James G. Nicholson ◽

...

Keyword(s):

Mapk Pathway ◽

Critical Role ◽

Cell Lineage ◽

Activating Mutations ◽

Pathway Activation ◽

Tumour Formation ◽

Conditional Expression ◽

Cell Cycle Inhibitors ◽

Mutation Braf

AbstractGermline mutations in BRAF and other components of the MAPK pathway are associated with the congenital syndromes collectively known as RASopathies. Here, we report the association of Septo-Optic Dysplasia (SOD) including hypopituitarism and Cardio-Facio-Cutaneous (CFC) syndrome in patients harbouring mutations in BRAF. Phosphoproteomic analyses demonstrate that these genetic variants are gain-of-function mutations leading to activation of the MAPK pathway. Activation of the MAPK pathway by conditional expression of the BrafV600E/+ allele, or the knock-in BrafQ241R/+ allele (corresponding to the most frequent human CFC-causing mutation, BRAF p.Q257R), leads to abnormal cell lineage determination and terminal differentiation of hormone-producing cells, causing hypopituitarism. Expression of the BrafV600E/+ allele in embryonic pituitary progenitors leads to an increased expression of cell cycle inhibitors, cell growth arrest and apoptosis, but not tumour formation. Our findings show a critical role of BRAF in hypothalamo-pituitary-axis development both in mouse and human and implicate mutations found in RASopathies as a cause of endocrine deficiencies in humans.

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