Laser-induced gene expression in specific cells of transgenic zebrafish

Development ◽  
2000 ◽  
Vol 127 (9) ◽  
pp. 1953-1960 ◽  
Author(s):  
M.C. Halloran ◽  
M. Sato-Maeda ◽  
J.T. Warren ◽  
F. Su ◽  
Z. Lele ◽  
...  

Over the past few years, a number of studies have described the generation of transgenic lines of zebrafish in which expression of reporters was driven by a variety of promoters. These lines opened up the real possibility that transgenics could be used to complement the genetic analysis of zebrafish development. Transgenic lines in which the expression of genes can be regulated both in space and time would be especially useful. Therefore, we have cloned the zebrafish promoter for the inducible hsp70 gene and made stable transgenic lines of zebrafish that express the reporter green fluorescent protein gene under the control of a hsp70 promoter. At normal temperatures, green fluorescent protein is not detectable in transgenic embryos with the exception of the lens, but is robustly expressed throughout the embryo following an increase in ambient temperature. Furthermore, we have taken advantage of the accessibility and optical clarity of the embryos to express green fluorescent protein in individual cells by focussing a sublethal laser microbeam onto them. The targeted cells appear to develop normally: cells migrate normally, neurons project axons that follow normal pathways, and progenitor cells divide and give rise to normal progeny cells. By generating other transgenic lines in which the hsp70 promoter regulates genes of interest, it should be possible to examine the in vivo activity of the gene products by laser-inducing specific cells to express them in zebrafish embryos. As a first test, we laser-induced single muscle cells to make zebrafish Sema3A1, a semaphorin that is repulsive for specific growth cones, in a hsp70-sema3A1 transgenic line of zebrafish and found that extension by the motor axons was retarded by the induced muscle.

Blood ◽  
1997 ◽  
Vol 90 (5) ◽  
pp. 1777-1786 ◽  
Author(s):  
Derek A. Persons ◽  
James A. Allay ◽  
Esther R. Allay ◽  
Richard J. Smeyne ◽  
Richard A. Ashmun ◽  
...  

Abstract We have investigated the utility of the green fluorescent protein (GFP) to serve as a marker to assess retroviral gene transfer into hematopoietic cells and as a tool to identify and enrich for cells expressing high levels of the vector-encoded transcript. GFP, by virtue of a naturally occurring chromophore encoded in its primary sequence, displays autonomous fluorescence, thus eliminating the need for antibody or cytochemical staining to detect its expression. A bicistronic murine stem cell virus (MSCV)-based retroviral vector was constructed containing the GFP cDNA and a mutant, human dihydrofolate reductase gene. High-titer, ecotropic retroviral producer cells free of replication competent virus were generated and used to transduce murine bone marrow cells by cocultivation. Within 24 hours after completion of the transduction procedure, a high proportion (40% to 70%) of the marrow cells were intensely fluorescent compared to mock-transduced cells or cells transduced with a control retrovirus. Erythroid and myeloid hematopoietic colonies derived from GFP-transduced marrow were easily scored for retroviral gene transfer by direct in situ fluorescence microscopy. Clonogenic progenitors expressing increased levels of antifolate drug resistance could be enriched from the GFP-transduced marrow population by fluorescence activated cell sorting of cells expressing high levels of GFP. In vivo, splenic hematopoietic colonies and peripheral blood cells from animals transplanted with GFP-transduced marrow displayed intense fluorescence. These results show that GFP is an excellent marker for scoring and tracking gene-modified hematopoietic cells and for allowing rapid selection and enrichment of transduced cells expressing high levels of the transgene.


2000 ◽  
Vol 7 (10) ◽  
pp. 1336-1340 ◽  
Author(s):  
Satoshi Hasegawa ◽  
Meng Yang ◽  
Takashi Chishima ◽  
Yohei Miyagi ◽  
Hiroshi Shimada ◽  
...  

2010 ◽  
Vol 192 (18) ◽  
pp. 4790-4793 ◽  
Author(s):  
Colin P. Corcoran ◽  
Andrew D. S. Cameron ◽  
Charles J. Dorman

ABSTRACT The bacterial nucleoid-associated protein H-NS, which preferentially targets and silences A+T-rich genes, binds the ubiquitous reporter gene gfp and dramatically reduces local transcription. We have redesigned gfp to reduce H-NS-mediated transcription silencing and simultaneously improve translation in vivo without altering the amino acid sequence of the GFP protein.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1156-1156
Author(s):  
Jing Zhang ◽  
Hui-Feng Lin ◽  
Robert I. Handin

Abstract The non-receptor tyrosine kinase Jak2 plays an important role in regulating erythro and thrombopoiesis. There has been intense interest in Jak2 since the observation that an activating mutation V617F is present in almost all patients with Polycythemia vera and many patients with Essential Thrombocytosis and Myelofibrosis. The analysis of Jak2 function in vivo has been limited as the murine jak2 knockout is lethal at day 10.5 of embryogenesis. Our laboratory has taken advantage of an ancestral partial duplication of the zebrafish genome, which has yielded two jak2 alleles --- jak2a and jak2b to study jak2 expression and function. Whole mount in situ hybridization studies confirm that the jak2a gene is only expressed in hematopoietic tissues, while jak2b is expressed in the developing lens and nephritic ducts. We have cloned and characterized the full-length jak2a and jak2b cDNAs and characterized the jak2a and 2b genomic loci. The jak2b gene has 24 exons spanning 79kb of genomic DNA. We amplified a 4kb zebrafish genomic fragment upstream of the first exon of the jak2b gene and linked it to the enhanced green fluorescent protein (EGFP) cDNA reporter and then microinjected the construct into single-cell zebrafish embryos. At 24 hours post fertilization (hpf), we observed fluorescence in the lens and nephritic ducts of developing embryos, with some expression in skin, muscle and notochord. The jak2a gene locus is complex as the jak2a gene is linked to a gene of unknown function, STARD4, in a head-to-tail manner with a small intergenic region of 1kb. As observed with jak2b, the first exon contains the jak2b 5′-UTR and the second exon contains the translation initiation site. We cloned a 1.9kb DNA fragment that included exons 1 and 2 the intervening first intron and an additional 800bp upstream of exon 1. This 1.9 kb promoter fragment was sufficient to drive expression of enhanced green fluorescent protein (EGFP) in injected embryos in a manner that recapitulated the native expression pattern of jak2a. In injected embryos 24hpf, GFP+ cells were present in the anterior intermediate cell mass (ICM) and the lens. Fluorescent circulating blood cells, largely erythrocytes, were detected in 12 of 124 microinjected embryos 48 hours after fertilization. The jak2-EGFP transgenic zebrafish strains should be useful in the study of normal and pathologic hematopoiesis and in future studies of the pathogenesis of the MPDs.


1999 ◽  
Vol 339 (2) ◽  
pp. 299-307 ◽  
Author(s):  
Arthur L. KRUCKEBERG ◽  
Ling YE ◽  
Jan A. BERDEN ◽  
Karel van DAM

The Hxt2 glucose transport protein of Saccharomyces cerevisiae was genetically fused at its C-terminus with the green fluorescent protein (GFP). The Hxt2-GFP fusion protein is a functional hexose transporter: it restored growth on glucose to a strain bearing null mutations in the hexose transporter genes GAL2 and HXT1 to HXT7. Furthermore, its glucose transport activity in this null strain was not markedly different from that of the wild-type Hxt2 protein. We calculated from the fluorescence level and transport kinetics that induced cells had 1.4×105 Hxt2-GFP molecules per cell, and that the catalytic-centre activity of the Hxt2-GFP molecule in vivo is 53 s-1 at 30 °C. Expression of Hxt2-GFP was induced by growth at low concentrations of glucose. Under inducing conditions the Hxt2-GFP fluorescence was localized to the plasma membrane. In a strain impaired in the fusion of secretory vesicles with the plasma membrane, the fluorescence accumulated in the cytoplasm. When induced cells were treated with high concentrations of glucose, the fluorescence was redistributed to the vacuole within 4 h. When endocytosis was genetically blocked, the fluorescence remained in the plasma membrane after treatment with high concentrations of glucose.


2021 ◽  
Vol 22 (8) ◽  
pp. 4073
Author(s):  
Yifan Lai ◽  
Qingyuan Feng ◽  
Rui Zhang ◽  
Jing Shang ◽  
Hui Zhong

To investigate a possible methodology of exploiting herbal medicine and design polytherapy for the treatment of skin depigmentation disorder, we have made use of Vernonia anthelmintica (L.) Willd., a traditional Chinese herbal medicine that has been proven to be effective in treating vitiligo. Here, we report that the extract of Vernonia anthelmintica (L.) Willd. effectively enhances melanogenesis responses in B16F10. In its compound library, we found three ingredients (butin, caffeic acid and luteolin) also have the activity of promoting melanogenesis in vivo and in vitro. They can reduce the accumulation of ROS induced by hydrogen peroxide and inflammatory response induced by sublethal concentrations of copper sulfate in wild type and green fluorescent protein (GFP)-labeled leukocytes zebrafish larvae. The overall objective of the present study aims to identify which compatibility proportions of the medicines may be more effective in promoting pigmentation. We utilized the D-optimal response surface methodology to optimize the ratio among three molecules. Combining three indicators of promoting melanogenesis, anti-inflammatory and antioxidant capacities, we get the best effect of butin, caffeic acid and luteolin at the ratio (butin:caffeic acid:luteolin = 7.38:28.30:64.32) on zebrafish. Moreover, the effect of melanin content recovery in the best combination is stronger than that of the monomer, which suggests that the three compounds have a synergistic effect on inducing melanogenesis. After simply verifying the result, we performed in situ hybridization on whole-mount zebrafish embryos to further explore the effects of multi-drugs combination on the proliferation and differentiation of melanocytes and the expression of genes (tyr, mitfa, dct, kit) related to melanin synthesis. In conclusion, the above three compatible compounds can significantly enhance melanogenesis and improve depigmentation in vivo.


2021 ◽  
Vol 30 ◽  
pp. 096368972097821
Author(s):  
Andrea Tenorio-Mina ◽  
Daniel Cortés ◽  
Joel Esquivel-Estudillo ◽  
Adolfo López-Ornelas ◽  
Alejandro Cabrera-Wrooman ◽  
...  

Human skin contains keratinocytes in the epidermis. Such cells share their ectodermal origin with the central nervous system (CNS). Recent studies have demonstrated that terminally differentiated somatic cells can adopt a pluripotent state, or can directly convert its phenotype to neurons, after ectopic expression of transcription factors. In this article we tested the hypothesis that human keratinocytes can adopt neural fates after culturing them in suspension with a neural medium. Initially, keratinocytes expressed Keratins and Vimentin. After neural induction, transcriptional upregulation of NESTIN, SOX2, VIMENTIN, SOX1, and MUSASHI1 was observed, concomitant with significant increases in NESTIN detected by immunostaining. However, in vitro differentiation did not yield the expression of neuronal or astrocytic markers. We tested the differentiation potential of control and neural-induced keratinocytes by grafting them in the developing CNS of rats, through ultrasound-guided injection. For this purpose, keratinocytes were transduced with lentivirus that contained the coding sequence of green fluorescent protein. Cell sorting was employed to select cells with high fluorescence. Unexpectedly, 4 days after grafting these cells in the ventricles, both control and neural-induced cells expressed green fluorescent protein together with the neuronal proteins βIII-Tubulin and Microtubule-Associated Protein 2. These results support the notion that in vivo environment provides appropriate signals to evaluate the neuronal differentiation potential of keratinocytes or other non-neural cell populations.


2014 ◽  
Vol 16 (6) ◽  
pp. 674-683 ◽  
Author(s):  
Chao Qiu ◽  
Bin Cheng ◽  
Yunsheng Zhang ◽  
Rong Huang ◽  
Lanjie Liao ◽  
...  

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