1
|
Abstract
The Tabula Gallus is a proposed project that aims to create a map of every cell type in the chicken body and chick embryos. Chickens (Gallus gallus) are one of the most recognized model animals that recapitulate the development and physiology of mammals. The Tabula Gallus will generate a compendium of single-cell transcriptome data from Gallus gallus, characterize each cell type, and provide tools for the study of the biology of this species, similar to other ongoing cell atlas projects (Tabula Muris and Tabula Sapiens/Human Cell Atlas for mice and humans, respectively). The Tabula Gallus will potentially become an international collaboration between many researchers. This project will be useful for the basic scientific study of Gallus gallus and other birds (e.g., cell biology, molecular biology, developmental biology, neuroscience, physiology, oncology, virology, behavior, ecology, and evolution). It will eventually be beneficial for a better understanding of human health and diseases.
Collapse
|
2
|
Abstract
For more than 2,000 years, philosophers and scientists have turned to the avian embryo with questions of how life begins (Aristotle and Peck Generations of Animals. Loeb Classics, vol. XIII. Harvard University Press, Cambridge, 1943; Needham, A history of embryology. Abelard-Schuman, New York, 1959). Then, as now, the unique accessibility of the embryo both in terms of acquisition of eggs from domesticated fowl and ease at which the embryo can be visualized by simply opening the shell has made avians an appealing and powerful model system for the study of development. Thus, as the field of embryology has evolved through observational, comparative, and experimental embryology into its current iteration as the cellular and molecular biology of development, avians have remained a useful and practical system of study.
Collapse
Affiliation(s)
- Michael Bressan
- Cardiovascular Research Institute, University of California, San Francisco, 555 Mission Bay Blvd South, MC3120, San Francisco, CA, 94143-3120, USA,
| | | |
Collapse
|
3
|
Borges RM, Horne JH, Melo A, Vidal JT, Vieceli FM, Melo MO, Kanno TYN, Fraser SE, Yan CYI. A detailed description of an economical setup for electroporation of chick embryos in ovo. Braz J Med Biol Res 2013; 46:752-7. [PMID: 24068190 PMCID: PMC3854436 DOI: 10.1590/1414-431x20133232] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Accepted: 06/07/2013] [Indexed: 11/28/2022] Open
Abstract
One of the challenges of the postgenomic era is characterizing the function and
regulation of specific genes. For various reasons, the early chick embryo can
easily be adopted as an in vivo assay of gene function and
regulation. The embryos are robust, accessible, easily manipulated, and
maintained in the laboratory. Genomic resources centered on vertebrate organisms
increase daily. As a consequence of optimization of gene transfer protocols by
electroporation, the chick embryo will probably become increasingly popular for
reverse genetic analysis. The challenge of establishing chick embryonic
electroporation might seem insurmountable to those who are unfamiliar with
experimental embryological methods. To minimize the cost, time, and effort
required to establish a chick electroporation assay method, we describe and
illustrate in great detail the procedures involved in building a low-cost
electroporation setup and the basic steps of electroporation.
Collapse
Affiliation(s)
- R M Borges
- Instituto de Ciências Biomédicas, Universidade de São Paulo, Departamento de Biologia Celular e do Desenvolvimento, São PauloSP, Brasil
| | | | | | | | | | | | | | | | | |
Collapse
|
4
|
Ex vivo electroporation of retinal cells: a novel, high efficiency method for functional studies in primary retinal cultures. Exp Eye Res 2013; 109:40-50. [PMID: 23370269 DOI: 10.1016/j.exer.2013.01.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Revised: 12/17/2012] [Accepted: 01/19/2013] [Indexed: 11/22/2022]
Abstract
Primary retinal cultures constitute valuable tools not only for basic research on retinal cell development and physiology, but also for the identification of factors or drugs that promote cell survival and differentiation. In order to take full advantage of the benefits of this system it is imperative to develop efficient and reliable techniques for the manipulation of gene expression. However, achieving appropriate transfection efficiencies in these cultures has remained challenging. The purpose of this work was to develop and optimize a technique that would allow the transfection of chick retinal cells with high efficiency and reproducibility for multiple applications. We developed an ex vivo electroporation method applied to dissociated retinal cell cultures that offers a significant improvement over other currently available transfection techniques, increasing efficiency by five-fold. In this method, eyes were enucleated, devoid of RPE, and electroporated with GFP-encoding plasmids using custom-made electrodes. Electroporated retinas were then dissociated into single cells and plated in low density conditions, to be analyzed after 4 days of incubation. Parameters such as voltage and number of electric pulses, as well as plasmid concentration and developmental stage of the animal were optimized for efficiency. The characteristics of the cultures were assessed by morphology and immunocytochemistry, and cell viability was determined by ethidium homodimer staining. Cell imaging and counting was performed using an automated high-throughput system. This procedure resulted in transfection efficiencies in the order of 22-25% of cultured cells, encompassing both photoreceptors and non-photoreceptor neurons, and without affecting normal cell survival and differentiation. Finally, the feasibility of the technique for cell-autonomous studies of gene function in a biologically relevant context was tested by carrying out gain and loss-of-function experiments for the transcription factor PAX6. Electroporation of a plasmid construct expressing PAX6 resulted in a marked upregulation in the expression levels of this protein that could be measured in the whole culture as well as cell-intrinsically. This was accompanied by a significant decrease in the percentage of cells differentiating as photoreceptors among the transfected population. Conversely, electroporation of an RNAi construct targeting PAX6 resulted in a significant decrease in the levels of this protein, with a concomitant increase in the proportion of photoreceptors. Taken together these results provide strong proof-of-principle of the suitability of this technique for genetic studies in retinal cultures. The combination of the high transfection efficiency obtained by this method with automated high-throughput cell analysis supplies the scientific community with a powerful system for performing functional studies in a cell-autonomous manner.
Collapse
|
5
|
Vergara MN, Canto-Soler MV. Rediscovering the chick embryo as a model to study retinal development. Neural Dev 2012; 7:22. [PMID: 22738172 PMCID: PMC3541172 DOI: 10.1186/1749-8104-7-22] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Accepted: 05/22/2012] [Indexed: 01/20/2023] Open
Abstract
The embryonic chick occupies a privileged place among animal models used in developmental studies. Its rapid development and accessibility for visualization and experimental manipulation are just some of the characteristics that have made it a vertebrate model of choice for more than two millennia. Until a few years ago, the inability to perform genetic manipulations constituted a major drawback of this system. However, the completion of the chicken genome project and the development of techniques to manipulate gene expression have allowed this classic animal model to enter the molecular age. Such techniques, combined with the embryological manipulations that this system is well known for, provide a unique toolkit to study the genetic basis of neural development. A major advantage of these approaches is that they permit targeted gene misexpression with extremely high spatiotemporal resolution and over a large range of developmental stages, allowing functional analysis at a level, speed and ease that is difficult to achieve in other systems. This article provides a general overview of the chick as a developmental model focusing more specifically on its application to the study of eye development. Special emphasis is given to the state of the art of the techniques that have made gene gain- and loss-of-function studies in this model a reality. In addition, we discuss some methodological considerations derived from our own experience that we believe will be beneficial to researchers working with this system.
Collapse
Affiliation(s)
- M Natalia Vergara
- Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Smith Building 3023, 400 N Broadway, Baltimore, MD 21287-9257, USA
| | - M Valeria Canto-Soler
- Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Smith Building 3023, 400 N Broadway, Baltimore, MD 21287-9257, USA
| |
Collapse
|
6
|
Yu F, Ding LJ, Sun GB, Sun PX, He XH, Ni LG, Li BC. Transgenic sperm produced by electrotransfection and allogeneic transplantation of chicken fetal spermatogonial stem cells. Mol Reprod Dev 2010; 77:340-7. [DOI: 10.1002/mrd.21147] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
7
|
Ishii Y, Weinberg K, Oda-Ishii I, Coughlin L, Mikawa T. Morphogenesis and cytodifferentiation of the avian retinal pigmented epithelium require downregulation of Group B1 Sox genes. Development 2009; 136:2579-89. [PMID: 19570849 DOI: 10.1242/dev.031344] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The optic vesicle is a multipotential primordium of the retina, which becomes subdivided into the neural retina and retinal pigmented epithelium domains. Although the roles of several paracrine factors in patterning the optic vesicle have been studied extensively, little is known about cell-autonomous mechanisms that regulate coordinated cell morphogenesis and cytodifferentiation of the retinal pigmented epithelium. Here we demonstrate that members of the SoxB1 gene family, Sox1, Sox2 and Sox3, are all downregulated in the presumptive retinal pigmented epithelium. Constitutive maintenance of SoxB1 expression in the presumptive retinal pigmented epithelium both in vivo and in vitro resulted in the absence of cuboidal morphology and pigmentation, and in concomitant induction of neural differentiation markers. We also demonstrate that exogenous Fgf4 inhibits downregulation all SoxB1 family members in the presumptive retinal pigment epithelium. These results suggest that retinal pigment epithelium morphogenesis and cytodifferentiation requires SoxB1 downregulation, which depends on the absence of exposure to an FGF-like signal.
Collapse
Affiliation(s)
- Yasuo Ishii
- University of California San Francisco, Cardiovascular Research Institute, Rock Hall Room 384D, San Francisco, CA 94158, USA
| | | | | | | | | |
Collapse
|
8
|
Smith CA, Roeszler KN, Sinclair AH. Robust and ubiquitous GFP expression in a single generation of chicken embryos using the avian retroviral vector, RCASBP. Differentiation 2009; 77:473-82. [DOI: 10.1016/j.diff.2009.02.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Revised: 01/17/2009] [Accepted: 02/23/2009] [Indexed: 01/25/2023]
|
9
|
Venters SJ, Dias da Silva MR, Hyer J. Murine retroviruses re-engineered for lineage tracing and expression of toxic genes in the developing chick embryo. Dev Dyn 2009; 237:3260-9. [PMID: 18942139 DOI: 10.1002/dvdy.21766] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
We describe two replication incompetent retroviral vectors that co-express green fluorescent protein (GFP) and beta-galactosidase. These vectors incorporate either the avian reticuloendotheliosis (spleen necrosis virus; SNV) promoter or the chick beta-actin promoter, into the backbone of the murine leukemia (MLV) viral vector. The additional promoters drive transgene expression in avian tissue. The remainder of the vector is MLV-like, allowing high titer viral particle production by means of transient transfection. The SNV promoter produces high and early expression of introduced genes, enabling detection of the single copy integrated GFP gene in infected cells and their progeny in vivo. Substitution of the LacZ coding DNA with a relevant gene of interest will enable its co-expression with GFP, thus allowing visualization of the effect of specific and stable changes in gene expression throughout development. As the VSV-G pseudotyped viral vector is replication incompetent, changes in gene expression can be controlled temporally, by altering the timing of introduction.
Collapse
Affiliation(s)
- Sara J Venters
- Department of Neurosurgery, University of California, San Francisco, California 94143, USA
| | | | | |
Collapse
|
10
|
King LA, Schwartz NB, Domowicz MS. Glial migratory streams in the developing hindbrain: a slice culture approach. J Neurosci Methods 2008; 177:30-43. [PMID: 18948137 DOI: 10.1016/j.jneumeth.2008.09.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Revised: 09/05/2008] [Accepted: 09/16/2008] [Indexed: 02/05/2023]
Abstract
Compared to our knowledge of neurogenesis, relatively little is known about glial cell specification and migration during central nervous system development. We have established a novel chick hindbrain slice preparation which permits examination of gliogenesis in its native environment, providing a means to study the signaling pathways involved in glial cell specification and migration during development. Cells in the hindbrain slice preparations mature in a manner which is similar to in vivo developmental timing and patterning paradigms. To demonstrate the utility of this approach, we examined the effect of the retinoic acid signaling pathway on cells in these slices, showing that addition of exogenous trans-retinoic acid to slice cultures promotes expression of a marker of mature astrocytes, glial fibrillary acidic protein (GFAP), while the inhibition of endogenous retinoic acid synthesis reduces GFAP expression; the results suggest a role for retinoic acid in modulating glial differentiation. Using these hindbrain slice cultures, we have used two different approaches to label glial progenitors specifically at the ventricular zone and have observed for the first time the ventrally-directed migration of these cells from the ventricular zone of the hindbrain. This slice culture system is thus an innovative and robust tool for examining glial cell migration and the extracellular molecular and signaling pathways which regulate glial differentiation.
Collapse
Affiliation(s)
- Leslie A King
- Department of Pediatrics, 5841 S. Maryland Avenue, MC 5058, The University of Chicago, Chicago, IL 60637, USA
| | | | | |
Collapse
|
11
|
Kohonen P, Nera KP, Lassila O. Avian model for B-cell immunology--new genomes and phylotranscriptomics. Scand J Immunol 2007; 66:113-21. [PMID: 17635788 DOI: 10.1111/j.1365-3083.2007.01973.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The purpose of this review is to discuss the use of chicken and other model organisms in the study of B-cell development and function as well as to highlight the opportunities afforded by the expanded genome-sequencing efforts. A brief introduction on chicken B-cell biology is followed by discussion of somatic cell reverse genetic approaches using the DT40 cell line. The unique advantages of the DT40 system are emphasized with discussion on B-cell receptor signalling research as well as on DNA repair and mechanisms of immunoglobulin diversification. An attempt is made to compare and contrast the results from chicken with mouse knockouts on the one hand and RNAi with human cell lines on the other. Chicken is also emerging strongly as a platform for gene expression analysis, and avian studies are compared with mammalian studies. Multi-species gene co-expression analysis, which could also be termed phylotranscriptomics, aims to use the evolutionary distance between organisms to its advantage. This approach, still in its infancy, is also reviewed and its applicability to the chicken is discussed.
Collapse
Affiliation(s)
- P Kohonen
- Turku Graduate School of Biomedical Sciences, Department of Medical Microbiology, University of Turku, Turku, Finland.
| | | | | |
Collapse
|
12
|
Tomanek RJ, Ishii Y, Holifield JS, Sjogren CL, Hansen HK, Mikawa T. VEGF family members regulate myocardial tubulogenesis and coronary artery formation in the embryo. Circ Res 2006; 98:947-53. [PMID: 16527987 DOI: 10.1161/01.res.0000216974.75994.da] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
This study tested the hypothesis that coronary tubulogenesis and coronary artery formation require VEGF family members. Quail embryos were injected with soluble vascular endothelial growth factor (VEGF) receptors R1 (Flt-1), R2 (Flk-1), R3 (Flt-4), VEGF-Trap (a chimera of R1 and R2), or neutralizing antibodies to VEGF-A, VEGF-B, or fibroblast growth factor (FGF)-2. Our data document that tubulogenesis is temporally dependent on multiple VEGF family members, because the early stage of tubulogenesis was markedly inhibited by VEGF-Trap and to a lesser extent by soluble VEGFR-1. Some inhibition of tubulogenesis was documented when anti-FGF-2, but not anti-VEGF-A, antibodies were injected at embryonic day 6 (E6). Most importantly, we found that VEGF-Trap injected at either E6 or E7 prevented the formation of coronary arteries. Soluble VEGFR-1 and soluble VEGFR-2 modified the formation of coronary arteries, whereas soluble VEGFR-3 was without effect. Antibodies to VEGF-B, but not VEGF-A, had a strong inhibitory effect on coronary artery development. The absence of coronary artery stems, and thus a functional coronary circulation, in the embryos injected with VEGF-Trap caused an accumulation of erythrocytes in the subepicardium and muscular interventricular septum. Using retroviral cell tagging, we showed that some of the erythrocytes in blood islands and small vascular tubes were progeny of the proepicardium. Thus, another salient finding of this study is the first definitive documentation of proepicardially derived hemangioblasts, which can differentiate into erythrocytes.
Collapse
Affiliation(s)
- Robert J Tomanek
- Department of Anatomy & Cell Biology, Cardiovascular Center, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA.
| | | | | | | | | | | |
Collapse
|
13
|
Mozdziak PE, Wu Q, Bradford JM, Pardue SL, Borwornpinyo S, Giamario C, Petitte JN. Identification of the lacZ insertion site and beta-galactosidase expression in transgenic chickens. Cell Tissue Res 2006; 324:41-53. [PMID: 16408197 DOI: 10.1007/s00441-005-0060-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2005] [Accepted: 07/25/2005] [Indexed: 10/25/2022]
Abstract
The quail:chick chimera system is a classical research model in developmental biology. An improvement over the quail:chick chimera system would be a line of transgenic chickens expressing a reporter gene. Transgenic chickens carrying lacZ and expressing bacterial beta-galactosidase have been generated, but complete characterization of the insertion event and characterization of beta-galactosidase expression have not previously been available. The genomic sequences flanking the retroviral insertion site have now been identified by using inverse polymerase chain reaction (PCR), homozygous individuals have been identified by using PCR-based genotyping, and beta-galactosidase expression has been evaluated by using Western analysis and histochemistry. Based upon the current draft of the chicken genome, the viral insertion carrying the lacZ gene has been located on chromosome 11 within the predicted gene for neurotactin/fractalkine (CX3CL1); neurotactin mRNA expression appears to be missing from the brain of homozygous individuals. When Generation 2 (G2) lacZ-positive individuals were inter-mated, they generated 361 G3 progeny; 82 were homozyous for lacZ (22.7%), 97 were wild-type non-transgenic (26.9%), and 182 (50.4%) were hemizygous for lacZ. Western analysis revealed the highest expression in the muscle and liver. With the identification of homozygous birds, the line of chickens is now designated NCSU-Blue1.
Collapse
Affiliation(s)
- Paul E Mozdziak
- Department of Poultry Science, North Carolina State University, Raleigh, NC 27695, USA.
| | | | | | | | | | | | | |
Collapse
|
14
|
Abstract
The chick embryo is a versatile model system, in which classical embryology can be combined with modern molecular approaches. In the last two decades, several efficient methods have been developed to introduce exogenous genes into the chick embryo. These techniques allow alteration of gene expression levels in a spatially and temporally restricted manner, thereby circumventing embryonic lethality and/or eliminating secondary effects in other tissues. Here, we present the current status of avian somatic transgenic techniques, focusing on electroporation and retrovirus-mediated gene transfer. Electroporation allows quick and efficient gain-of-function studies based on transient misexpression of genes. Retroviral vectors, which are capable of integrating exogenous genes into the host chromosome, permit analysis of long-term effects of gene misexpression. The variety of methods available for somatic transgenesis, along with the recent completion of the chicken genome, are transforming the chick embryo into one of the most attractive model systems to examine function of genes that are important for embryonic development.
Collapse
Affiliation(s)
- Yasuo Ishii
- Department of Cell and Developmental Biology, Cornell University Medical College, New York, New York 10021, USA
| | | |
Collapse
|
15
|
Chen AE, Fan CM. Targeting gene expression in the mouse somite: Adenovirus-mediated gene delivery and whole embryo culture. Genesis 2005; 42:71-6. [PMID: 15880591 DOI: 10.1002/gene.20126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We report here a novel approach to direct gene expression in the mouse somite based on the combined application of adenovirus-mediated gene delivery and whole embryo ex vivo culture. As proof of principle, we show functional analysis of somites microinjected with an engineered virus expressing an activated form of Smoothened, the signaling receptor for Sonic Hedgehog (SHH). As adenovirus can infect many embryonic tissues in the mouse, this method may provide an effective alternative to conventional transgenesis for targeted spatial and temporal gene expression.
Collapse
Affiliation(s)
- Alice E Chen
- Department of Embryology, Carnegie Institution of Washington, Baltimore, MD, USA
| | | |
Collapse
|
16
|
Schmid M, Nanda I, Hoehn H, Schartl M, Haaf T, Buerstedde JM, Arakawa H, Caldwell RB, Weigend S, Burt DW, Smith J, Griffin DK, Masabanda JS, Groenen MAM, Crooijmans RPMA, Vignal A, Fillon V, Morisson M, Pitel F, Vignoles M, Garrigues A, Gellin J, Rodionov AV, Galkina SA, Lukina NA, Ben-Ari G, Blum S, Hillel J, Twito T, Lavi U, David L, Feldman MW, Delany ME, Conley CA, Fowler VM, Hedges SB, Godbout R, Katyal S, Smith C, Hudson Q, Sinclair A, Mizuno S. Second report on chicken genes and chromosomes 2005. Cytogenet Genome Res 2005; 109:415-79. [PMID: 15905640 DOI: 10.1159/000084205] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Affiliation(s)
- M Schmid
- Department of Human Genetics, University of Würzburg, Würzburg, Germany.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Chapman SC, Lawson A, Macarthur WC, Wiese RJ, Loechel RH, Burgos-Trinidad M, Wakefield JK, Ramabhadran R, Mauch TJ, Schoenwolf GC. Ubiquitous GFP expression in transgenic chickens using a lentiviral vector. Development 2005; 132:935-40. [PMID: 15673573 DOI: 10.1242/dev.01652] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
We report the first ubiquitous green fluorescent protein expression in chicks using a lentiviral vector approach, with eGFP under the control of the phosphoglycerol kinase promoter. Several demonstrations of germline transmission in chicks have been reported previously, using markers that produce tissue-specific, but not ubiquitous, expression. Using embryos sired by a heterozygous male, we demonstrate germline transmission in the embryonic tissue that expresses eGFP uniformly, and that can be used in tissue transplants and processed by in situ hybridization and immunocytochemistry. Transgenic tissue is identifiable by both fluorescence microscopy and immunolabeling, resulting in a permanent marker identifying transgenic cells following processing of the tissue. Stable integration of the transgene has allowed breeding of homozygous males and females that will be used to produce transgenic embryos in 100% of eggs laid upon reaching sexual maturity. These results demonstrate that a transgenic approach in the chick model system is viable and useful even though a relatively long generation time is required. The transgenic chick model will benefit studies on embryonic development, as well as providing the pharmaceutical industry with an economical bioreactor.
Collapse
Affiliation(s)
- Susan C Chapman
- University of Utah School of Medicine, Department of Neurobiology and Anatomy, and Children's Health Research Center, Room 401 MREB, 20 North 1900 East Salt Lake City, Utah 84132-3401, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|