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1.
Methods Mol Biol ; 2224: 153-182, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33606214

RESUMO

Hematopoiesis in the mouse and other mammals occurs in several waves and arises from distinct anatomic sites. Transgenic mice expressing fluorescent reporter proteins at various points in the hematopoietic hierarchy, from hematopoietic stem cell to more restricted progenitors to each of the final differentiated cell types, have provided valuable tools for tagging, tracking, and isolating these cells. In this chapter, we discuss general considerations in designing a transgene, survey available fluorescent probes, and describe methods for confirming and analyzing transgene expression in the hematopoietic tissues of the embryo, fetus, and postnatal/adult animal.


Assuntos
Genes Reporter/genética , Hematopoese/genética , Proteínas Luminescentes/genética , Animais , Diferenciação Celular/genética , Embrião de Mamíferos/fisiologia , Feminino , Feto/fisiologia , Células-Tronco Hematopoéticas/fisiologia , Masculino , Camundongos , Camundongos Transgênicos , Células-Tronco/fisiologia , Transgenes/genética
2.
Methods Mol Biol ; 2224: 203-214, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33606217

RESUMO

Duchenne muscular dystrophy (DMD) is a devastating X-linked muscle disorder affecting many children. The disease is caused by the lack of dystrophin production and characterized by muscle wasting. The most common causes of death are respiratory failure and heart failure. Antisense oligonucleotide-mediated exon skipping using a phosphorodiamidate morpholino oligomer (PMO) is a promising therapeutic approach for the treatment of DMD. In preclinical studies, dystrophic mouse models are commonly used for the development of therapeutic oligos. We employ a humanized model carrying the full-length human DMD transgene along with the complete knockout of the mouse Dmd gene. In this model, the effects of human-targeting AOs can be tested without cross-reaction between mouse sequences and human sequences (note that mdx, a conventional dystrophic mouse model, carries a nonsense point mutation in exon 23 and express the full-length mouse Dmd mRNA, which is a significant complicating factor). To determine if dystrophin expression is restored, the Western blotting analysis is commonly performed; however, due to the extremely large protein size of dystrophin (427 kDa), detection and accurate quantification of full-length dystrophin can be a challenge. Here, we present methodologies to systemically inject PMOs into humanized DMD model mice and determine levels of dystrophin restoration via Western blotting. Using a tris-acetate gradient SDS gel and semi-dry transfer with three buffers, including the Concentrated Anode Buffer, Anode Buffer, and Cathode Buffer, less than 1% normal levels of dystrophin expression are easily detectable. This method is fast, easy, and sensitive enough for the detection of dystrophin from both cultured muscle cells and muscle biopsy samples.


Assuntos
Distrofina/genética , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/terapia , Oligonucleotídeos Antissenso/genética , Animais , Western Blotting/métodos , Modelos Animais de Doenças , Éxons/genética , Terapia Genética/métodos , Humanos , Camundongos , Camundongos Endogâmicos mdx , Músculo Esquelético/metabolismo , RNA Mensageiro/genética , Transgenes/genética
3.
J Immunol ; 206(2): 432-445, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33310871

RESUMO

Although neutrophils play important roles in immunity and inflammation, their analysis is strongly hindered by their short-lived and terminally differentiated nature. Prior studies reported conditional immortalization of myeloid progenitors using retroviral expression of an estrogen-dependent fusion protein of the HoxB8 transcription factor. This approach allowed the long-term culture of mouse myeloid progenitors (HoxB8 progenitors) in estrogen-containing media, followed by differentiation toward neutrophils upon estrogen withdrawal. Although several reports confirmed the in vitro functional responsiveness of the resulting differentiated cells (HoxB8 neutrophils), little is known about their capacity to perform in vivo neutrophil functions. We have addressed this issue by an in vivo transplantation approach. In vitro-generated HoxB8 neutrophils showed a neutrophil-like phenotype and were able to perform conventional neutrophil functions, like respiratory burst, chemotaxis, and phagocytosis. The i.v. injection of HoxB8 progenitors into lethally irradiated recipients resulted in the appearance of circulating donor-derived HoxB8 neutrophils. In vivo-differentiated HoxB8 neutrophils were able to migrate to the inflamed peritoneum and to phagocytose heat-killed Candida particles. The reverse passive Arthus reaction could be induced in HoxB8 chimeras but not in irradiated, nontransplanted control animals. Repeated injection of HoxB8 progenitors also allowed us to maintain stable circulating HoxB8 neutrophil counts for several days. Injection of arthritogenic K/B×N serum triggered robust arthritis in HoxB8 chimeras, but not in irradiated, nontransplanted control mice. Taken together, our results indicate that HoxB8 progenitor-derived neutrophils are capable of performing various in vivo neutrophil functions, providing a framework for using the HoxB8 system for the in vivo analysis of neutrophil function.


Assuntos
Adenoviridae/genética , Vetores Genéticos/genética , Proteínas de Homeodomínio/metabolismo , Inflamação/imunologia , Células Progenitoras Mieloides/imunologia , Neutrófilos/imunologia , Animais , Diferenciação Celular , Linhagem Celular Transformada , Quimiotaxia , Regulação da Expressão Gênica , Proteínas de Homeodomínio/genética , Camundongos , Camundongos Endogâmicos C57BL , Transdução de Sinais , Transgenes/genética
4.
Nat Commun ; 11(1): 4903, 2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-32994412

RESUMO

The CRISPR-Cas9 system has increased the speed and precision of genetic editing in cells and animals. However, model generation for drug development is still expensive and time-consuming, demanding more target flexibility and faster turnaround times with high reproducibility. The generation of a tightly controlled ObLiGaRe doxycycline inducible SpCas9 (ODInCas9) transgene and its use in targeted ObLiGaRe results in functional integration into both human and mouse cells culminating in the generation of the ODInCas9 mouse. Genomic editing can be performed in cells of various tissue origins without any detectable gene editing in the absence of doxycycline. Somatic in vivo editing can model non-small cell lung cancer (NSCLC) adenocarcinomas, enabling treatment studies to validate the efficacy of candidate drugs. The ODInCas9 mouse allows robust and tunable genome editing granting flexibility, speed and uniformity at less cost, leading to high throughput and practical preclinical in vivo therapeutic testing.


Assuntos
Sistemas CRISPR-Cas/genética , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Descoberta de Drogas/métodos , Edição de Genes/métodos , Neoplasias Pulmonares/tratamento farmacológico , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Proteína 9 Associada à CRISPR/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Linhagem Celular Tumoral , Doxiciclina/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Feminino , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Vetores Genéticos/genética , Células HEK293 , Ensaios de Triagem em Larga Escala/métodos , Humanos , Neoplasias Pulmonares/genética , Masculino , Camundongos , Camundongos Transgênicos , RNA Guia/genética , Recombinação Genética/efeitos dos fármacos , Reprodutibilidade dos Testes , Ativação Transcricional/efeitos dos fármacos , Transfecção/métodos , Transgenes/genética
5.
PLoS One ; 15(9): e0239435, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32946490

RESUMO

The genotyping of genetically-modified cells is a crucial step in studies of transgenics and genomic editing with systems such as CRISPR/Cas. The detection of genome editing events can be directly related to the genotyping methodology used, which is influenced by its costs, since many experiments require the analysis of a large number of samples. The aim of this study was to compare the performance of direct lysis methods of genomic DNA (gDNA) extraction for the detection of knockins and knockouts in primary goat cells. Initially, three gDNA extraction protocols (protocol A, heat denaturation/freeze-thaw in water; protocol B, heat denaturation/proteinase K; and protocol C, CellsDirect Kit) were tested using different quantities (1,000, 5,000 and 10,000 cells) and types of goat primary cells (fibroblasts and goat mammary epithelial cells-GMECs) for subsequent validation by PCR amplification of small (GAPDH) and large amplicons (hLF transgene). All protocols were successful in the detection of the small amplicon; however, in GMECs, only protocol B resulted efficient amplification (protocol A-0%, protocol B-93%, protocol C-13.33%, P <0.05). In a proof-of-principle experiment, the TP53 gene was knocked out in GMECs by CRISPR/Cas9-mediated deletion while constructs containing the anti-VEGF monoclonal antibody (pBC-anti-VEGF) and bacterial L-Asparaginase (pBC-ASNase) transgenes were knocked-in separately in fibroblasts. Detection of successful editing was performed using protocol B and PCR. The integration rates of the pBC-ASNase and pBC-anti-VEGF transgenes were 93.6% and 72%, respectively, as per PCR. The efficiency of biallelic editing in GMECs using CRISPR/Cas9 for the TP53 deletion was 5.4%. Our results suggest that protocol B (heat denaturation/proteinase K) can be used as an inexpensive and quick methodology for detecting genetic modifications in different types of primary goat cells, with efficiency rates consistent with values previously described in the literature when using extraction kits or more complex proteinase K formulations.


Assuntos
Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Análise Custo-Benefício , DNA/genética , DNA/isolamento & purificação , Edição de Genes , Transgenes/genética , Animais , Sequência de Bases , Fibroblastos/citologia , Fibroblastos/metabolismo , Cabras
6.
J Biosci Bioeng ; 130(5): 533-538, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32773266

RESUMO

Like endogenous proteins, recombinant foreign proteins produced in human cell lines also need post-translational modifications. However, high and long-term expression of a gene of interest (GOI) presents significant challenges for recombinant protein production in human cells. In this work, the effect of human matrix attachment region elements (MARs), including the ß-globin MAR (gMAR), chicken lysozyme MAR (cMAR), and a combination of these two, on the stable expression of GOI was assessed in human HT-1080 cells. After transfection with vectors containing the MAR elements and eGFP, stably HT-1080 cell pools were obtained under selective pressure. eGFP protein expression was analyzed by flow cytometry, while transgene copy number and eGFP mRNA expression levels were determined with qPCR and qRT-PCR technology. We found that MARs could not enhance transfection efficiency, but gMAR could significantly increase eGFP expression in stable HT-1080 cell pools by approximately 2.69-fold. Moreover, gMAR could also increase eGFP expression stability during long-term culture. Lastly, we showed that the effect of the MARs on transgenes was related to the gene copy number. In summary, this study found that MARs could both enhance the transgene expression and stability in HT-1080 cells.


Assuntos
Engenharia Genética/métodos , Regiões de Interação com a Matriz/genética , Proteínas Recombinantes de Fusão/genética , Linhagem Celular , Dosagem de Genes , Expressão Gênica , Proteínas de Fluorescência Verde/genética , Humanos , Transfecção , Transgenes/genética
7.
Proc Natl Acad Sci U S A ; 117(37): 22805-22814, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32839345

RESUMO

A Cas9/guide RNA-based gene drive strain, AgNosCd-1, was developed to deliver antiparasite effector molecules to the malaria vector mosquito, Anopheles gambiae The drive system targets the cardinal gene ortholog producing a red-eye phenotype. Drive can achieve 98 to 100% in both sexes and full introduction was observed in small cage trials within 6 to 10 generations following a single release of gene-drive males. No genetic load resulting from the integrated transgenes impaired drive performance in the trials. Potential drive-resistant target-site alleles arise at a frequency <0.1, and five of the most prevalent polymorphisms in the guide RNA target site in collections of colonized and wild-derived African mosquitoes do not prevent cleavage in vitro by the Cas9/guide RNA complex. Only one predicted off-target site is cleavable in vitro, with negligible deletions observed in vivo. AgNosCd-1 meets key performance criteria of a target product profile and can be a valuable component of a field-ready strain for mosquito population modification to control malaria transmission.


Assuntos
Anopheles/genética , Tecnologia de Impulso Genético/métodos , Controle de Mosquitos/métodos , Alelos , Animais , Animais Geneticamente Modificados/genética , Sistemas CRISPR-Cas/genética , Genética Populacional/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Malária/prevenção & controle , Mosquitos Vetores/genética , Fenótipo , Transgenes/genética
8.
PLoS One ; 15(7): e0232915, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32706785

RESUMO

Chimeric antigen receptor (CAR) T cell therapy is an effective treatment for B cell malignancies, with emerging potential for the treatment of other hematologic cancers and solid tumors. The strength of the promoter within the CAR cassette will alter CAR-polypeptide levels on the cell surface of the T cell-impacting on the kinetics of activation, survival and memory cell formation in T cells. In addition to the CAR, promoters can be used to drive other genes of interest to enhance CAR T cell function. Expressing multiple genes from a single RNA transcript can be effectively achieved by linking the genes via a ribosomal skip site. However, promoters may differ in their ability to transcribe longer RNAs, or could interfere with lentiviral production, or transduction frequencies. In this study we compared the ability of the strong well-characterized promoters CMV, EF-1, hPGK and RPBSA to drive functional expression of a single RNA encoding three products: GFP, CAR, plus an additional cell-survival gene, Mcl-1. Although the four promoters produced similarly high lentiviral titres, EF-1 gave the best transduction efficacy of primary T cells. Major differences were found in the ability of the promoters to drive expression of long RNA encoding GFP, CAR and Mcl-1, highlighting promoter choice as an important consideration for gene therapy applications requiring the expression of long and complex mRNA.


Assuntos
Engenharia Genética/métodos , Regiões Promotoras Genéticas/genética , Receptores de Antígenos Quiméricos/genética , Linfócitos T/metabolismo , Expressão Gênica , Células HEK293 , Humanos , Lentivirus/genética , Células MCF-7 , RNA Mensageiro/genética , Transgenes/genética
9.
Nat Commun ; 11(1): 2494, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32427850

RESUMO

Artificially improving traits of cultivated alfalfa (Medicago sativa L.), one of the most important forage crops, is challenging due to the lack of a reference genome and an efficient genome editing protocol, which mainly result from its autotetraploidy and self-incompatibility. Here, we generate an allele-aware chromosome-level genome assembly for the cultivated alfalfa consisting of 32 allelic chromosomes by integrating high-fidelity single-molecule sequencing and Hi-C data. We further establish an efficient CRISPR/Cas9-based genome editing protocol on the basis of this genome assembly and precisely introduce tetra-allelic mutations into null mutants that display obvious phenotype changes. The mutated alleles and phenotypes of null mutants can be stably inherited in generations in a transgene-free manner by cross pollination, which may help in bypassing the debate about transgenic plants. The presented genome and CRISPR/Cas9-based transgene-free genome editing protocol provide key foundations for accelerating research and molecular breeding of this important forage crop.


Assuntos
Cromossomos de Plantas/genética , Edição de Genes/métodos , Genoma de Planta/genética , Medicago sativa/genética , Tetraploidia , Transgenes/genética , Alelos , Sistemas CRISPR-Cas , Produtos Agrícolas/genética , Mutação , Fenótipo , Melhoramento Vegetal/métodos
10.
Nat Commun ; 11(1): 2214, 2020 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-32371941

RESUMO

MSH1 is a plant-specific protein. RNAi suppression of MSH1 results in phenotype variability for developmental and stress response pathways. Segregation of the RNAi transgene produces non-genetic msh1 'memory' with multi-generational inheritance. First-generation memory versus non-memory comparison, and six-generation inheritance studies, identifies gene-associated, heritable methylation repatterning. Genome-wide methylome analysis integrated with RNAseq and network-based enrichment studies identifies altered circadian clock networks, and phytohormone and stress response pathways that intersect with circadian control. A total of 373 differentially methylated loci comprising these networks are sufficient to discriminate memory from nonmemory full sibs. Methylation inhibitor 5-azacytidine diminishes the differences between memory and wild type for growth, gene expression and methylation patterning. The msh1 reprogramming is dependent on functional HISTONE DEACETYLASE 6 and methyltransferase MET1, and transition to memory requires the RNA-directed DNA methylation pathway. This system of phenotypic plasticity may serve as a potent model for defining accelerated plant adaptation during environmental change.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Metilação de DNA , Proteína MutS de Ligação de DNA com Erro de Pareamento/genética , Característica Quantitativa Herdável , Interferência de RNA , Transgenes/genética , Adaptação Fisiológica/genética , DNA (Citosina-5-)-Metiltransferases/genética , Epigênese Genética , Perfilação da Expressão Gênica/métodos , Ontologia Genética , Redes Reguladoras de Genes , Estudo de Associação Genômica Ampla/métodos , Desacetilase 6 de Histona/genética , Padrões de Herança/genética , Plantas Geneticamente Modificadas , Transdução de Sinais/genética
11.
PLoS One ; 15(4): e0232045, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32330156

RESUMO

The functional efficiency of the expression cassettes integrated into a plasmid and a PCR- amplified fragment was comparatively analyzed after transient transfection in vitro or introduction into the developing embryo of Danio rerio. The cassettes contained the reporter genes, luciferase of Photinus pyralis (luc) or enhanced green fluorescent protein, under the control of the promoter of human cytomegalovirus immediate-early genes. In the in vitro system, the efficiency of the circular plasmid was 2.5 times higher than that of the PCR- amplified fragment. The effect of mutations in the expression cassette on the efficiency of the transgene expression in the PCR- amplified fragment was quantitatively evaluated. The mutations generated after 25 amplification cycles with Taq DNA polymerase decreased luciferase activity in transfected cells by 65-85%. Thus, mutations are the key factor of decreased functional efficiency of the PCR- amplified fragment relative to the circular plasmid in this experimental model, while other factors apparently have a lesser impact. At the organism level, no significant difference in the expression efficiency of the plasmid and PCR- amplified fragment has been revealed. Comparison of the vector efficiencies in in vivo and in vitro systems demonstrates that the level of luciferase in the D. rerio cell lysate, normalized to the molar concentration of the vector, is by three orders of magnitude higher than that after the cell transfection in vitro, which indicates that the quantitative data obtained for in vitro systems should not be directly extrapolated to the organism level.


Assuntos
Genes Reporter/genética , Vetores Genéticos/genética , Reação em Cadeia da Polimerase/métodos , Animais , Linhagem Celular Tumoral , Eficiência/fisiologia , Vaga-Lumes/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Luciferases/metabolismo , Plasmídeos/genética , Regiões Promotoras Genéticas/genética , Transfecção/métodos , Transgenes/genética , Peixe-Zebra/metabolismo
12.
J Neurosci ; 40(20): 3896-3914, 2020 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-32300046

RESUMO

Optic neuropathies are a group of optic nerve (ON) diseases caused by various insults including glaucoma, inflammation, ischemia, trauma, and genetic deficits, which are characterized by retinal ganglion cell (RGC) death and ON degeneration. An increasing number of genes involved in RGC intrinsic signaling have been found to be promising neural repair targets that can potentially be modulated directly by gene therapy, if we can achieve RGC specific gene targeting. To address this challenge, we first used adeno-associated virus (AAV)-mediated gene transfer to perform a low-throughput in vivo screening in both male and female mouse eyes and identified the mouse γ-synuclein (mSncg) promoter, which specifically and potently sustained transgene expression in mouse RGCs and also works in human RGCs. We further demonstrated that gene therapy that combines AAV-mSncg promoter with clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 gene editing can knock down pro-degenerative genes in RGCs and provide effective neuroprotection in optic neuropathies.SIGNIFICANCE STATEMENT Here, we present an RGC-specific promoter, mouse γ-synuclein (mSncg) promoter, and perform extensive characterization and proof-of-concept studies of mSncg promoter-mediated gene expression and clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 gene editing in RGCs in vivo To our knowledge, this is the first report demonstrating in vivo neuroprotection of injured RGCs and optic nerve (ON) by AAV-mediated CRISPR/Cas9 inhibition of genes that are critical for neurodegeneration. It represents a powerful tool to achieve RGC-specific gene modulation, and also opens up a promising gene therapy strategy for optic neuropathies, the most common form of eye diseases that cause irreversible blindness.


Assuntos
Regulação da Expressão Gênica/genética , Edição de RNA/genética , Células Ganglionares da Retina/metabolismo , gama-Sinucleína/genética , Animais , Sistemas CRISPR-Cas , Dependovirus/genética , Feminino , Deleção de Genes , Terapia Genética , Humanos , Células-Tronco Pluripotentes Induzidas , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Nervo Óptico/patologia , Doenças do Nervo Óptico/genética , Doenças do Nervo Óptico/terapia , Células Ganglionares da Retina/patologia , Transgenes/genética
13.
J Immunol ; 204(7): 1982-1987, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32122998

RESUMO

GFP is frequently used as a marker for tracking donor cells adoptively transplanted into recipient animals. The human ubiquitin C promoter (UBC)-driven-GFP transgenic mouse is a commonly used source of donor cells for this purpose. This mouse was initially generated in the C57BL/6 inbred strain and has been backcrossed into the BALB/cBy strain for over 11 generations. Both the C57BL/6 inbred and BALB/cBy congenic UBC-GFP lines are commercially available and have been widely distributed. These UBC-GFP lines can be a convenient resource for tracking donor cells in both syngenic MHC-matched and in allogenic MHC-mismatched studies as C57BL/6 (H-2b) and BALB/cBy (H-2d) have disparate MHC haplotypes. In this report, we surprisingly discover that the UBC-GFP BALB/cBy congenic mice still retain the H-2b MHC haplotype of their original C57BL/6 founder, suggesting that the UBC-GFP transgene integration site is closely linked to the MHC locus on chromosome 17. Using linear amplification-mediated PCR, we successfully map the UBC-GFP transgene to the MHC locus. This study highlights the importance and urgency of mapping the transgene integration site of transgenic mouse strains used in biomedical research. Furthermore, this study raises the possibility of alternative interpretations of previous studies using congenic UBC-GFP mice and focuses attention on the necessity for rigor and reproducibility in scientific research.


Assuntos
Cromossomos/genética , Proteínas de Fluorescência Verde/genética , Complexo Principal de Histocompatibilidade/genética , Mutagênese Insercional/genética , Transgenes/genética , Ubiquitina C/genética , Animais , Haplótipos/genética , Camundongos , Camundongos Congênicos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Regiões Promotoras Genéticas/genética , Reprodutibilidade dos Testes
14.
Invest Ophthalmol Vis Sci ; 61(2): 14, 2020 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-32049344

RESUMO

Purpose: Experimental access to specific cell subtypes is essential for deciphering the complexity of retinal networks. Here, we characterized the selective labeling, caused by ectopic transgene expression, of two atypical retinal neurons in the ChAT-Channelrhodopsin-2 (ChR2)-EYFP mouse. Methods: Retinal sections and flat-mounts were prepared for double-staining immunohistochemistry with antibodies against EYFP and various neuronal markers. Sagittal/coronal brain slices were made to visualize EYFP signals in central nuclei. Whole-cell recordings were conducted to test the functionality of ChR2. Results: Two populations of EYFP-positive retinal cells were observed. The inner nuclear layer (INL)-located one (type I cell) distributed regularly throughout the entire retina, whereas the ganglion cell layer (GCL)-residing one (type II cell) was restricted ventrally. None of them was cholinergic, as evidenced by the complete absence of ChAT immunoreactivity. Type I cells were immunolabeled by the amacrine marker syntaxin. However, the vast majority of them were neither positive to GABA/GAD65, nor to GlyT1/glycine, suggesting that they were non-GABAergic non-glycinergic amacrine cells (nGnG ACs), which was confirmed by double-labeling with the nGnG AC marker PPP1R17. Type II cells were immunopositive to melanopsin, but not to Brn3a or Brn3b. They possessed dendrites stratifying in the outermost inner plexiform layer (IPL) and axons projecting to the suprachiasmatic nucleus (SCN) rather than the olivary pretectal nucleus (OPN), suggesting that they belonged to a Brn3b-negative subset of M1-type intrinsically photosensitive retinal ganglion cells (ipRGCs). Glutamatergic transmission-independent photocurrents were elicited in EYFP-positive cells, indicating the functional expression of ChR2. Conclusions: The ChAT-ChR2-EYFP retina exhibits ectopic, but functional, transgene expression in nGnG ACs and SCN-innervating M1 ipRGCs, thus providing an ideal tool to achieve efficient labeling and optogenetic manipulation of these cells.


Assuntos
Células Amácrinas/metabolismo , Proteínas de Homeodomínio/metabolismo , Células Ganglionares da Retina/metabolismo , Fator de Transcrição Brn-3B/metabolismo , Transgenes/fisiologia , Animais , Channelrhodopsins/metabolismo , Colina O-Acetiltransferase/metabolismo , Feminino , Expressão Gênica , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Transgenes/genética
15.
Exp Anim ; 69(3): 279-286, 2020 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-32051389

RESUMO

Transgene insertion patterns are critical for the analysis of transgenic animals because the influence of transgenes may change depending on the insertion pattern (such as copy numbers and orientations of concatenations) and the insertion position in the genome. We previously reported a genomic walking strategy to locate transgenes in the genomes of transgenic mice (Exp. Anim. 53: 103-111, 2004) and to analyze transgene insertion patterns (Exp. Anim. 55: 65-69, 2006). With such strategies, however, we could not determine the copy number of transgenes or global genome modification induced by transgene insertion due to read-length limitation. In this study, we used a long-read sequencer (MinION, Oxford Nanopore Technologies) to overcome this limitation. We obtained 922,210 reads using MinION with genomic DNA from a transgenic mouse strain (4C30, Proc. Jpn. Acad. Ser. B. Phys. Biol. Sci. 87: 550-562, 2011). Among the reads, we found one 21,457-bp read containing the transgene using a local BLAST search. Nucleotide dot plot analysis revealed that the transgene was inserted in the genome as a tandem concatemer with an almost entire construct (15-3,508 of 3,508 bp) and a partial fragment (4-660, 657 bp). Ensembl's BLAST search against the C57BL/6N genome revealed a 9,388-bp deletion at the insertion position in the intron of the Sgcd gene, confirming that mutations such as a large genomic deletion could occur at the time of transgene insertion. Thus, long-read sequencers are useful tools for the analysis of transgene insertion patterns.


Assuntos
Mutagênese Insercional , Análise de Sequência de DNA/métodos , Transgenes/genética , Animais , Genoma/genética , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mutação , Sarcoglicanas/genética
16.
Exp Anim ; 69(3): 287-294, 2020 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-32051391

RESUMO

The pronuclear injection (PI)-based targeted transgenesis (PITT) method allows the generation of targeted transgenic (Tg) mice wherein a single copy of a transgene is integrated into the Rosa26 locus following PI. The Rosa26 locus allows unbiased ubiquitous expression of integrated transgenes; however, it remains little known whether tissue-specific promoters retain their functional properties when placed at the Rosa26 locus. We evaluated tissue-specific activity and reproducibility of exogenous tissue-specific promoters targeted to the Rosa26 locus by generating Thy1-Dre/Dre reporter mice using PITT and assessed spatial expression patterns of the transgenes. The Thy1 promoter targeted to the Rosa26 locus appeared active in virtually all Purkinje cells in the cerebellum and hippocampus. However, mosaic expression of the transgene under the Thy1 promoter was observed in many other organs. This phenomenon was consistent in all the Tg lines generated by PITT, indicating a high degree of reproducibility for this experiment.


Assuntos
Expressão Gênica/genética , Regiões Promotoras Genéticas/genética , RNA não Traduzido/genética , Animais , Encéfalo/metabolismo , Genótipo , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , RNA não Traduzido/metabolismo , Transgenes/genética
17.
PLoS One ; 15(2): e0228203, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32027678

RESUMO

We previously developed an in vivo site-specific transfection method using a suction device in mice; namely, a tissue suction-mediated transfection method (tissue suction method). The aim of this study was to apply the tissue suction method for cardiac gene transfer. Naked plasmid DNA (pDNA) was intravenously injected in mice, followed by direct suction on the beating heart by using a suction device made of polydimethylsiloxane. We first examined the effects of suction conditions on transgene expression and toxicity. Subsequently, we analyzed transgene-expressing cells and the transfected region of the heart. We found that heart suction induced transgene expression, and that -75 kPa and -90 kPa of suction achieved high transgene expression. In addition, the inner diameter of the suction device was correlated with transgene expression, but the pressure hold time did not change transgene expression. Although the tissue suction method at -75 kPa induced a transient increase in the serum cardiac toxicity markers at 6 h after transfection, these markers returned to normal at 24 h. The cardiac damage was also analyzed through the measurement of hypertrophic gene expression, but no significant differences were found. In addition, the cardiac function monitored by echocardiography remained normal at 11 days after transfection. Immunohistochemical analysis revealed that CD31-positive endothelial cells co-expressed the ZsGreen1-N1 reporter gene. In conclusion, the tissue suction method can achieve an efficient and safe gene transfer to the beating heart in mice.


Assuntos
Coração/fisiologia , Miocárdio/metabolismo , Transfecção/métodos , Transgenes/genética , Animais , Creatina Quinase Forma MB/sangue , Dimetilpolisiloxanos/química , Ecocardiografia , Expressão Gênica , Camundongos , Miocárdio/patologia , Cadeias Pesadas de Miosina/genética , Cadeias Pesadas de Miosina/metabolismo , Plasmídeos/administração & dosagem , Plasmídeos/genética , Plasmídeos/metabolismo , Pressão , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/genética , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Transfecção/instrumentação , Troponina T/sangue
18.
Appl Microbiol Biotechnol ; 104(5): 2125-2135, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31932895

RESUMO

Recent research has shown that plants can uptake long dsRNAs and dsRNA-derived siRNAs that target important genes of infecting fungi or viruses when applied on the surface of plant leaves. The external RNAs were capable of local and systemic movement inducing plant resistance against the pathogens. Few studies have been made for plant gene regulation by foliar application of RNAs. In this study, several types of ssRNA and siRNA duplexes targeting the neomycin phosphotransferase II (NPTII) transgene were in vitro-synthesized and externally applied to the leaf surface of 4-week-old transgenic Arabidopsis thaliana plants. External application of the synthetic NPTII-encoding siRNAs down-regulated NPTII transcript levels in transgenic A. thaliana 1 and 7 days post-treatment with a higher and more consistent effect being observed for siRNAs methylated at 3' ends. We also analyzed the effects of external NPTII-encoding dsRNA precursors and a dsRNA-derived heterogenous siRNA mix. Digestion of the NPTII-dsRNA to the heterogeneous siRNAs did not improve efficiency of the transgene suppression effect. Key Points• Foliar application of siRNAs down-regulated a commonly used transgene in Arabidopsis. • A more consistent effect was observed for methylated siRNAs. • The findings are important for development of plant gene regulation approaches.


Assuntos
Regulação da Expressão Gênica de Plantas , Inativação Gênica , RNA Interferente Pequeno/genética , Transgenes/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Sequência de Bases , Metilação de DNA , Regulação da Expressão Gênica de Plantas/genética , Canamicina Quinase/genética , Canamicina Quinase/metabolismo , Folhas de Planta/genética , Folhas de Planta/metabolismo , Plantas Geneticamente Modificadas , RNA de Cadeia Dupla/genética , RNA de Cadeia Dupla/metabolismo , RNA Interferente Pequeno/metabolismo , Transcrição Genética
19.
Exp Cell Res ; 388(2): 111852, 2020 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-31972219

RESUMO

Artificial chromosome platforms are described in plants. Because the function of centromeres is largely epigenetic, attempts to produce artificial chromosomes with plant centromere DNA have failed. The removal of the centromeric sequences from the cell strips off the centromeric histone that is the apparent biochemical marker of centromere activity. Thus, engineered minichromosomes have been produced by telomere mediated chromosomal truncation. The introduction of telomere repeats will cleave the chromosome at the site of insertion and attach the accompanying transgenes in the process. Such truncation events have been documented in maize, Arabidopsis, barley, rice, Brassica and wheat. Truncation of the nonvital supernumerary B chromosome of maize is a favorite target but engineered minichromosomes derived from the normal A chromosomes have also been recovered. Transmission through mitosis of small chromosomes is apparently normal but there is loss during meiosis. Potential solutions to address this issue are discussed. With procedures now well established to produce the foundation for artificial chromosomes in plants, current efforts are directed at building them up to specification using gene stacking methods and editing techniques.


Assuntos
Cromossomos Artificiais , Engenharia Genética/métodos , Plantas/genética , Transgenes/genética
20.
PLoS One ; 15(1): e0228164, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31995598

RESUMO

Most of the approved monoclonal antibodies used in the clinic were initially discovered in mice. However, many targets of therapeutic interest are highly conserved proteins that do not elicit a robust immune response in mice. There is a need for non-mammalian antibody discovery platforms which would allow researchers to access epitopes that are not recognized in mammalian hosts. Recently, we introduced the OmniChicken®, a transgenic animal carrying human VH3-23 and VK3-15 at its immunoglobulin loci. Here, we describe a new version of the OmniChicken which carries VH3-23 and either VL1-44 or VL3-19 at its heavy and light chain loci, respectively. The Vλ-expressing birds showed normal B and T populations in the periphery. A panel of monoclonal antibodies demonstrated comparable epitope coverage of a model antigen compared to both wild-type and Vκ-expressing OmniChickens. Kinetic analysis identified binders in the picomolar range. The Vλ-expressing bird increases the antibody diversity available in the OmniChicken platform, further enabling discovery of therapeutic leads.


Assuntos
Animais Geneticamente Modificados/genética , Galinhas/genética , Cadeias lambda de Imunoglobulina/genética , Animais , Animais Geneticamente Modificados/imunologia , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/imunologia , Linfócitos B/imunologia , Galinhas/imunologia , Humanos , Imunidade Humoral , Cadeias Pesadas de Imunoglobulinas/genética , Região Variável de Imunoglobulina/genética , Cadeias lambda de Imunoglobulina/imunologia , Progranulinas/imunologia , Linfócitos T/imunologia , Transgenes/genética
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