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Mori T, Devlin RH. Transgene and host growth hormone gene expression in pituitary and nonpituitary tissues of normal and growth hormone transgenic salmon. Mol Cell Endocrinol 1999; 149:129-39. [PMID: 10375025 DOI: 10.1016/s0303-7207(98)00248-2] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Growth hormone (GH) gene expression has been examined in control and transgenic coho salmon containing a transgene comprised of the sockeye salmon GH1 gene under the control of the MT-B promoter from the same species. This transgene dramatically enhances the growth of salmonids, and raises serum GH levels some forty-fold. Transcript levels from this transgene were detected by RT-PCR using construct-specific GH primers in all tissues examined (liver, kidney, skin, intestine, stomach, muscle, spleen, pyloric caeca), and ranged from 0.1 - 9.4 pg/50 microg total RNA in different tissues as estimated by dot blot analysis. Interestingly, GH gene expression was also observed in intestine of control coho salmon by RT-PCR capable of detecting host and transgene transcripts using general primers. Sequence analysis of the intestinal GH mRNA from controls indicated it was derived from the coho GH2 gene. GH mRNA abundance analyzed by northern analysis indicates lower levels are found in large (400-500 g) than small transgenic salmon (20-21 g). No molecular evidence for transgene expression was obtained in tissues from transgenic fry, despite an obvious increase in size relative to control siblings, suggesting very low levels of transgene expression early in development. GH mRNA levels (per microg RNA) were also examined in the pituitary gland, and were found to be significantly lower (P < 0.01) in transgenic coho compared to nontransgenic animals of the same size. Pituitary glands of transgenic animals were also smaller than control animals of the same size, and pituitary size, expressed as a proportion of body weight, decreased with body size in transgenic but not control animals. These results imply that pituitary GH expression is regulated by negative feed-back controls as occurs in other vertebrate systems. GH mRNA was examined in pituitary glands by whole-mount in situ hybridization, and, whereas overall levels appeared reduced in transgenic animals, the site of hybridization did not differ between transgenic and control glands.
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Affiliation(s)
- T Mori
- Laboratory of Physiology, Faculty of Fisheries, Hokkaido University, Hakodate, Japan.
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2
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Cerdán MG, Young JI, Zino E, Falzone TL, Otero V, Torres HN, Rubinstein M. Accurate spatial and temporal transgene expression driven by a 3.8-kilobase promoter of the bovine beta-casein gene in the lactating mouse mammary gland. Mol Reprod Dev 1998; 49:236-45. [PMID: 9491375 DOI: 10.1002/(sici)1098-2795(199803)49:3<236::aid-mrd3>3.0.co;2-p] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The spatial, temporal, and hormonal pattern of expression of the beta-casein gene is highly regulated and confined to the epithelial cells of the lactating mammary gland. Previous studies have shown that 1.7 kb of the bovine beta-casein promoter were able to drive cell-specific and hormone-dependent expression to a mouse mammary cell line but failed to induce accurate expression to the mammary gland of transgenic mice. We investigated here the ability of 3.8 kb of the bovine beta-casein gene promoter to drive the expression of the human growth hormone (hGH) gene in transgenic mice. A Northern blot analysis using total RNA obtained from different tissues of lactating and nonlactating females revealed the presence of hGH mRNA only in the mammary gland of lactating females. hGH mRNA was not detectable in the mammary gland of virgin females or males. A developmental analysis showed that hGH mRNA only peaked on parturition, resembling more closely the bovine beta-casein temporal expression pattern rather than the murine. In situ hibridization studies performed on mammary gland sections showed that the cellular pattern of hGH expression was homogeneous in all lobules from heterozygous and homozygous transgenic mice. Silver grain counts on the tissue sections highly correlated with the hGH contents in the milk determined by radioimmunoassay (r = 0.996). Thus 3.8 kb of the bovine beta-casein promoter direct a high-level expression of a reporter gene to the lactating mammary gland of transgenic mice in a tissue-specific and developmentally regulated manner.
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Affiliation(s)
- M G Cerdán
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (CONICET-UBA), Buenos Aires, Argentina
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3
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Wang TC, Koh TJ, Varro A, Cahill RJ, Dangler CA, Fox JG, Dockray GJ. Processing and proliferative effects of human progastrin in transgenic mice. J Clin Invest 1996; 98:1918-29. [PMID: 8878444 PMCID: PMC507632 DOI: 10.1172/jci118993] [Citation(s) in RCA: 235] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Incompletely processed gastrins have been postulated to play a role in growth of the gastrointestinal tract, but few studies have examined the effects of progastrin on mucosal proliferation in vivo. Human gastrin gene expression and progastrin processing were therefore studied in transgenic mice containing a human gastrin (hGAS) minigene, and compared to processing in mice bearing an insulin gastrin (INS-GAS) transgene that overexpresses amidated gastrin. Progastrin processing was studied using region-specific antisera and radioimmunoassays, biosynthetic labeling, immunoprecipitation, and HPLC. Proliferative effects due to overexpression of processed and unprocessed gastrin in INS-GAS and hGAS mice, respectively, were determined using routine histology and BrdU incorporation. The pancreatic islets of INS-GAS mice were able to produce carboxyamidated G-17, resulting in a twofold elevation of serum amidated gastrin, marked thickening of the oxyntic mucosa, and an increased BrdU labeling index (LI) of the gastric body. In contrast, livers of adult hGAS mice expressed abundant human gastrin mRNA and human progastrin but were unable to process this peptide to the mature amidated form, resulting in markedly elevated serum progastrin levels and normal amidated gastrin levels. Nevertheless, there was a marked increase in the BrdU labeling index of the colon in hGAS mice (LI 7.46+/-1.90%), as well as in INS-GAS mice (LI 6.16+/-1.17%), compared to age-matched, wild type control mice (LI 4.01+/-0.98%, P < 0.05). These studies suggest that incompletely processed gastrin precursors may contribute to colonic mucosal proliferation in vivo.
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Affiliation(s)
- T C Wang
- Department of Medicine, Massachusetts General Hospital, Boston 02114, USA.
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4
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Douhet P, Destrade C, Bucchini D, Calas A. Expression of a human insulin transgene in cholinergic neurons of the mouse medial habenula. Biol Cell 1995; 85:137-46. [PMID: 8785515 DOI: 10.1016/0248-4900(96)85274-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We explored the possibility that an insulin gene deleted in its 5'-flanking region is expressed in adult mouse brain. We used three independent lines of mice carrying a human insulin transgene which included the insulin gene transcription unit flanked by 168 base pairs upstream and 5.5 kb downstream. Using a reverse transcription-polymerase chain reaction assay, human insulin mRNAs were detected in whole brain extracts. In all three lines, human insulin mRNAs were localized by in situ hybridization in a single cerebral site, the medial habenula. With a monoclonal antibody specific for human C-peptide and human proinsulin, labelling was restricted to a subset of habenular cholinergic neurons, with rare immunostained fibers. No labelling was observed in the projection fibers of the retroflexus fasciculus or in their axon terminals in the interpeduncular nucleus. Electron microscope studies suggested that the transgene expressing cells. These findings demonstrate that the human insulin transgene tested here includes a habenula specific promoter which could be useful for physiological and molecular studies on the habenula.
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Affiliation(s)
- P Douhet
- Laboratoire de Neurobiologie des Signaux Intercellulaires, Institut des Neurosciences, Paris, France
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5
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Banerjee SA, Roffler-Tarlov S, Szabo M, Frohman L, Chikaraishi DM. DNA regulatory sequences of the rat tyrosine hydroxylase gene direct correct catecholaminergic cell-type specificity of a human growth hormone reporter in the CNS of transgenic mice causing a dwarf phenotype. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1994; 24:89-106. [PMID: 7968381 DOI: 10.1016/0169-328x(94)90121-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Transgenic mice bearing 4.8 kilobases (kb) of upstream rat tyrosine hydroxylase (TH) sequences linked to a human growth hormone gene (hGH) exhibited cell-specific expression of hGH in all the appropriate catecholaminergic neurons in the central nervous system (CNS), although with different penetrance in two different mouse lineages. No ectopic expression was observed in any brain or peripheral region in one founder and its progeny. In another founder there was some ectopic expression in addition to appropriate and high levels of tissue-specific expression in all catecholaminergic areas. These results identify regulatory sequences that are sufficient for targeting expression to all catecholaminergic CNS neurons. Also, expression of exogenous hGH in the hypothalamus caused a dwarf phenotype, generating a novel genetic model for GH deficiency of hypothalamic origin.
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Affiliation(s)
- S A Banerjee
- Department of Microbiology, Tufts University School of Medicine, Boston, MA 02111
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6
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Affiliation(s)
- J M Rondeel
- Division of Endocrinology, Brown University, Rhode Island Hospital, Providence
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7
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Schneider LE, Roberts MS, Taghert PH. Cell type-specific transcriptional regulation of the Drosophila FMRFamide neuropeptide gene. Neuron 1993; 10:279-91. [PMID: 8439413 DOI: 10.1016/0896-6273(93)90318-l] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
We have used lacZ reporter gene constructs to study the promoter/enhancer regions of the Drosophila FMRFamide neuropeptide gene in germ line transformants. FMRFamide is normally expressed in approximately 60 diverse neurons of the larval CNS that represent approximately 15 distinct cell types. An 8 kb FMRFamide DNA fragment (including 5 kb of 5' upstream sequence) was sufficient to direct a pattern of lacZ expression that mimicked nearly all spatial aspects of the normal pattern. This result indicates that the cell-specific regulation of FMRFamide expression is largely generated by transcriptional mechanisms. Reporter gene expression was lost from selected cell types when smaller fragments were tested, suggesting that multiple control regions are included in the FMRFamide promoter. One region (a 300 bp fragment from -476 to -162) acted as an enhancer for 1 of the approximately 15 FMRFamide-positive cell types, the OL2 neurons. These results suggest that, in the mature nervous system, the complex pattern of FMRFamide neuropeptide gene expression derives from the activity of discrete, cell type-specific enhancers that are independently regulated.
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Affiliation(s)
- L E Schneider
- Department of Anatomy and Neurobiology, Washington University School of Medicine, Saint Louis, Missouri 63110
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8
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Rubinstein M, Liu B, Goodman RH, Low MJ. Targeted expression of somatostatin in vasopressinergic magnocellular hypothalamic neurons of transgenic mice. Mol Cell Neurosci 1992; 3:152-61. [DOI: 10.1016/1044-7431(92)90019-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/1991] [Indexed: 11/30/2022] Open
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Murphy D, Ang HL, Zeng Q, Ho MY, Funkhouser J, Carter D. Neuropeptide gene expression in transgenic animals. PROGRESS IN BRAIN RESEARCH 1992; 92:77-96. [PMID: 1302889 DOI: 10.1016/s0079-6123(08)61166-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Transgenic animal techniques offer today's neuroscientist the ability to experimentally manipulate neurosecretory systems with a precision undreamt of by our predecessors. The range of techniques now available, building as it does on our growing knowledge of physiological systems at the inter- and intercellular level, allows us to critically define molecular lesions and ask about their consequences to the whole organism. Neuroscientist should grasp the opportunities afforded by these recent developments.
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Affiliation(s)
- D Murphy
- Neuropeptide Laboratory, National University of Singapore
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10
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11
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Connelly CS, Fahl WE, Iannaccone PM. The role of transgenic animals in the analysis of various biological aspects of normal and pathologic states. Exp Cell Res 1989; 183:257-76. [PMID: 2670592 DOI: 10.1016/0014-4827(89)90387-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The introduction of foreign genes into the germ line of mammals has been a practical reality now for a number of years. This form of experimentation allows the creation of lines of animals tailor-made to answer specific molecular genetic questions. Manipulation of the mammalian embryos has been enormously important in developmental biology in recent years and that experience has brought about the possibility of new experiments allowing the molecular analysis of many biological processes. The methodologies involved in constructing transgenic animals have been published extensively in a number of comprehensive reviews. In typical experiments, pronuclear stage (one cell) embryos are collected after fertilization, but prior to the onset of cleavage. Exogenous cloned linearized DNA is injected into one of the two pronuclei by means of a finely drawn injection pipet. The manipulated embryo is transferred into the oviduct or ovarian bursal space of a surrogate mother previously mated with a sterile male. Alternative methods include retroviral transfection of cleavage stage embryos or insertion of genetically engineered embryo-derived embryonal stem cells into blastocysts. Offspring from these procedures are screened by standard molecular analyses to determine presence of the foreign genetic material. The present report explores the application of this methodology to a specific set of problems: (i) regulation of gene expression in vivo, (ii) the establishment of disease models for the study of pathogenesis, (iii) the use of exogenous genetic elements to correct specific genetic defects, (iv) the role of insertional mutagenesis in disruption of normal development, (v) analysis of genetic ablation, (iv) the use of transgenic animals to modulate carcinogens.
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Affiliation(s)
- C S Connelly
- Department of Pathology, Northwestern University, Chicago, Illinois 60611
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12
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Differential regulation of rat beta-casein-chloramphenicol acetyltransferase fusion gene expression in transgenic mice. Mol Cell Biol 1989. [PMID: 2710117 DOI: 10.1128/mcb.9.2.560] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Previous studies in our laboratory have demonstrated the mammary-specific expression of the entire rat beta-casein gene with 3.5 kilobases (kb) of 5' and 3.0 kb of 3' DNA in transgenic mice (Lee et al., Nucleic Acids Res. 16:1027-1041, 1988). In an attempt to localize sequences that dictate this specificity, lines of transgenic mice carrying two different rat beta-casein promoter-bacterial chloramphenicol acetyltransferase (cat) fusion genes have been established. Twenty and eight lines of transgenic mice carrying two fusion genes containing either 2.3 or 0.5 kb, respectively, of 5'-flanking DNA of the rat beta-casein gene along with noncoding exon I and 0.5 kb of intron A were identified, most of which transmitted the transgenes to their offspring in a Mendelian pattern. CAT activity was detected predominantly in the lactating mammary gland of female transgenic mice but not in the male mammary fat pad. A several-hundred-fold variation in the level of cat expression was observed in the mammary gland of different lines of mice, presumably due to the site of integration of the transgenes. CAT activity was increased in the mammary gland during development from virgin to midpregnancy and lactation. Unexpectedly, the casein-cat transgenes were also expressed in the thymus of different lines of both male and female mice, in some cases at levels equivalent to those observed in the mammary gland, and in contrast to the mammary gland, CAT activity was decreased during pregnancy and lactation in the thymus. Thus, 0.5 kb of 5'-flanking DNA of the rat beta-casein gene along with noncoding exon I and 0.5 kb of intron A are sufficient to target bacterial cat gene expression to the mammary gland of lactating mice.
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13
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A Mup promoter-thymidine kinase reporter gene shows relaxed tissue-specific expression and confers male sterility upon transgenic mice. Mol Cell Biol 1989. [PMID: 2850469 DOI: 10.1128/mcb.8.11.4821] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
A hybrid gene was made by fusing the 2.2-kilobase 5' promoter region of a mouse group 1 major urinary protein (Mup) gene to the coding region of the herpes simplex virus type 1 thymidine kinase gene (HSV tk) and introduced into the genomes of mice by microinjection. Transgenic G0 males were sterile, or when fertile did not transmit the foreign gene, and the transgenic male descendants of G0 females were also sterile. Seven "lines" were established by breeding from G0 females and their transgenic female descendants. Six lines expressed HSV thymidine kinase activity in the liver, and activity correlated perfectly with the presence of HSV tk RNA. In three of four lines examined, expression was lower in female than in male liver, and in these lines the same sex difference was observed in the rate of run-on transcription of the foreign genes in liver nuclei. When females of one of the sexually dimorphic lines were treated with testosterone, the levels of HSV tk RNA and thymidine kinase activity were increased, although not to male levels. In these aspects of liver expression, and also in a lack of expression in seven other tissues, the hybrid gene exhibits many of the characteristics of an endogenous group 1 Mup gene. However, the gene was also expressed (at high levels) in the preputial gland and testis, two tissues in which Mup genes are not expressed. The gene, when introduced into five of the seven lines, carried a copy of the Escherichia coli supF gene attached beyond the 3' end of the HSV tk gene, but this did not affect the overall expression pattern. All of the lines were male sterile and expressed HSV thymidine kinase in the testis, but one line showed no activity in the liver, and another showed none in the preputial gland. Testicular expression is therefore the likely cause of sterility. Data are described which suggest that the causes of misexpression in the preputial gland and testis are different. Since expression in each tissue occurred in several lines, the structure of the hybrid gene must be responsible in each case. Five intensively studied lines showed at least four consistently different patterns of relative expression in preputial gland, testis, male liver, and female liver. These differences do not correlate in any way with the copy number of the foreign gene in the different lines and must be due to some other aspect of line specific integration.
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14
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Lee KF, Atiee SH, Rosen JM. Differential regulation of rat beta-casein-chloramphenicol acetyltransferase fusion gene expression in transgenic mice. Mol Cell Biol 1989; 9:560-5. [PMID: 2710117 PMCID: PMC362632 DOI: 10.1128/mcb.9.2.560-565.1989] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Previous studies in our laboratory have demonstrated the mammary-specific expression of the entire rat beta-casein gene with 3.5 kilobases (kb) of 5' and 3.0 kb of 3' DNA in transgenic mice (Lee et al., Nucleic Acids Res. 16:1027-1041, 1988). In an attempt to localize sequences that dictate this specificity, lines of transgenic mice carrying two different rat beta-casein promoter-bacterial chloramphenicol acetyltransferase (cat) fusion genes have been established. Twenty and eight lines of transgenic mice carrying two fusion genes containing either 2.3 or 0.5 kb, respectively, of 5'-flanking DNA of the rat beta-casein gene along with noncoding exon I and 0.5 kb of intron A were identified, most of which transmitted the transgenes to their offspring in a Mendelian pattern. CAT activity was detected predominantly in the lactating mammary gland of female transgenic mice but not in the male mammary fat pad. A several-hundred-fold variation in the level of cat expression was observed in the mammary gland of different lines of mice, presumably due to the site of integration of the transgenes. CAT activity was increased in the mammary gland during development from virgin to midpregnancy and lactation. Unexpectedly, the casein-cat transgenes were also expressed in the thymus of different lines of both male and female mice, in some cases at levels equivalent to those observed in the mammary gland, and in contrast to the mammary gland, CAT activity was decreased during pregnancy and lactation in the thymus. Thus, 0.5 kb of 5'-flanking DNA of the rat beta-casein gene along with noncoding exon I and 0.5 kb of intron A are sufficient to target bacterial cat gene expression to the mammary gland of lactating mice.
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Affiliation(s)
- K F Lee
- Department of Cell Biology, Baylor College of Medicine, Houston, Texas 77030
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15
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Camper SA, Godbout R, Tilghman SM. The developmental regulation of albumin and alpha-fetoprotein gene expression. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 1989; 36:131-43. [PMID: 2471987 DOI: 10.1016/s0079-6603(08)60167-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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16
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Gene Transfer Through Embryo Microinjection. Anim Biotechnol 1989. [DOI: 10.1016/b978-0-08-034730-1.50015-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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17
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Affiliation(s)
- J W Gordon
- Brookdale Center for Molecular Biology, Department of Geriatrics and Adult Development, New York
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18
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Compere SJ, Baldacci P, Jaenisch R. Oncogenes in transgenic mice. BIOCHIMICA ET BIOPHYSICA ACTA 1988; 948:129-49. [PMID: 3052590 DOI: 10.1016/0304-419x(88)90008-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- S J Compere
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142
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19
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Al-Shawi R, Burke J, Jones CT, Simons JP, Bishop JO. A Mup promoter-thymidine kinase reporter gene shows relaxed tissue-specific expression and confers male sterility upon transgenic mice. Mol Cell Biol 1988; 8:4821-8. [PMID: 2850469 PMCID: PMC365575 DOI: 10.1128/mcb.8.11.4821-4828.1988] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
A hybrid gene was made by fusing the 2.2-kilobase 5' promoter region of a mouse group 1 major urinary protein (Mup) gene to the coding region of the herpes simplex virus type 1 thymidine kinase gene (HSV tk) and introduced into the genomes of mice by microinjection. Transgenic G0 males were sterile, or when fertile did not transmit the foreign gene, and the transgenic male descendants of G0 females were also sterile. Seven "lines" were established by breeding from G0 females and their transgenic female descendants. Six lines expressed HSV thymidine kinase activity in the liver, and activity correlated perfectly with the presence of HSV tk RNA. In three of four lines examined, expression was lower in female than in male liver, and in these lines the same sex difference was observed in the rate of run-on transcription of the foreign genes in liver nuclei. When females of one of the sexually dimorphic lines were treated with testosterone, the levels of HSV tk RNA and thymidine kinase activity were increased, although not to male levels. In these aspects of liver expression, and also in a lack of expression in seven other tissues, the hybrid gene exhibits many of the characteristics of an endogenous group 1 Mup gene. However, the gene was also expressed (at high levels) in the preputial gland and testis, two tissues in which Mup genes are not expressed. The gene, when introduced into five of the seven lines, carried a copy of the Escherichia coli supF gene attached beyond the 3' end of the HSV tk gene, but this did not affect the overall expression pattern. All of the lines were male sterile and expressed HSV thymidine kinase in the testis, but one line showed no activity in the liver, and another showed none in the preputial gland. Testicular expression is therefore the likely cause of sterility. Data are described which suggest that the causes of misexpression in the preputial gland and testis are different. Since expression in each tissue occurred in several lines, the structure of the hybrid gene must be responsible in each case. Five intensively studied lines showed at least four consistently different patterns of relative expression in preputial gland, testis, male liver, and female liver. These differences do not correlate in any way with the copy number of the foreign gene in the different lines and must be due to some other aspect of line specific integration.
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Affiliation(s)
- R Al-Shawi
- Department of Genetics, University of Edinburgh, Scotland
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20
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21
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Pittius CW, Hennighausen L, Lee E, Westphal H, Nicols E, Vitale J, Gordon K. A milk protein gene promoter directs the expression of human tissue plasminogen activator cDNA to the mammary gland in transgenic mice. Proc Natl Acad Sci U S A 1988; 85:5874-8. [PMID: 2842753 PMCID: PMC281867 DOI: 10.1073/pnas.85.16.5874] [Citation(s) in RCA: 112] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Whey acidic protein (WAP) is a major whey protein in mouse milk. Its gene is expressed in the lactating mammary gland and is inducible by steroid and peptide hormones. A series of transgenic mice containing a hybrid gene in which human tissue plasminogen activator (tPA) cDNA is under the control of the murine WAP gene promoter had previously been generated. In this study, 21 tissues from lactating and virgin transgenic female mice containing the WAP-tPA hybrid gene were screened for the distribution of murine WAP and human tPA transcripts. Like the endogenous WAP RNA, WAP-tPA RNA was expressed predominantly in mammary gland tissue and appeared to be inducible by lactation. Whereas WAP transcripts were not detected in 22 tissues of virgin mice, low levels of WAP-tPA RNA, which were not modulated during lactation, were found in tongue, kidney, and sublingual gland. These studies demonstrate that the WAP gene promoter can target the expression of a transgene to the mammary gland and that this expression is inducible during lactation.
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Affiliation(s)
- C W Pittius
- National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892
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22
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Allen ND, Cran DG, Barton SC, Hettle S, Reik W, Surani MA. Transgenes as probes for active chromosomal domains in mouse development. Nature 1988; 333:852-5. [PMID: 3386733 DOI: 10.1038/333852a0] [Citation(s) in RCA: 186] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Embryonic development entails a well defined temporal and spatial programme of gene expression, which may be influenced by active chromosomal domains. These chromosomal domains can be detected using transgenes which integrate randomly throughout the genome, as their expression can be affected by chromosomal position. Position effects are probably exerted most strongly on transgenes that do not contain strong promoters, enhancers or other modulating sequences. Here we have systematically explored position effects using a transgene with the weak herpes-simplex-virus thymidine-kinase promoter, linked to the readily visualized lacZ indicator gene (HSV-TK-lacZ). Each transgenic fetus with detectable expression displayed a unique lacZ staining pattern. Thus expression of this construct is apparently dictated entirely by its chromosomal position, without any construct specificity. Furthermore the transgene is faithfully transmitted to subsequent generations, allowing for systematic mapping of changes in expression during development and in adult life. These results demonstrate that transgenes can indeed be powerful tools to probe the genome for active chromosomal regions, with the potential for identifying endogenous genes involved in organogenesis and pattern formation.
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Affiliation(s)
- N D Allen
- Department of Molecular Embryology, Institute of Animal Physiology and Genetics Research, Babraham, Cambridge, UK
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23
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Russo AF, Crenshaw EB, Lira SA, Simmons DM, Swanson LW, Rosenfeld MG. Neuronal expression of chimeric genes in transgenic mice. Neuron 1988; 1:311-20. [PMID: 3078520 DOI: 10.1016/0896-6273(88)90079-7] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Gene expression may occur in unexpected ectopic sites when diverse genetic elements are juxtaposed as chimeric genes in transgenic mice. To determine the specific contribution of the promoter and reporter gene in ectopic expression, we have analyzed the expression of 14 different fusion genes in transgenic mice. Chimeric genes containing the mouse metallothionein-I promoter linked to either the rat or human growth hormone gene or the calcitonin/CGRP gene are expressed in a very similar pattern of neuronal regions. This ectopic expression is not a unique feature of the metallothionein promoter, since transferring the human growth hormone gene to four other heterologous promoters resulted in varying degrees of ectopic expression in overlapping subsets of cortical and hypothalamic neurons. The novel pattern of ectopic expression suggests that these otherwise unrelated neurons share a common developmental regulatory machinery for activation of gene transcription.
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Affiliation(s)
- A F Russo
- Center for Molecular Genetics and Eukaryotic Regulatory Biology Program, University of California, San Diego, La Jolla 92093
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Cwikel BJ, Habener JF. Provasopressin-neurophysin II processing is cell-specific in heterologous cell lines expressing a metallothionein-vasopressin fusion gene. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)47928-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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25
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Gordon JW, Chesa PG, Nishimura H, Rettig WJ, Maccari JE, Endo T, Seravalli E, Seki T, Silver J. Regulation of Thy-1 gene expression in transgenic mice. Cell 1987; 50:445-52. [PMID: 2886226 DOI: 10.1016/0092-8674(87)90498-3] [Citation(s) in RCA: 108] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Genomic DNA fragments encompassing the human Thy-1 or mouse Thy-1.1 gene have been microinjected into pronuclei of mouse embryos homozygous for the Thy-1.2 allele. In the resulting transgenic mice, the human gene is expressed in a pattern characteristic of normal human tissues, and is not influenced by the pattern of endogenous mouse Thy-1 expression. The mouse Thy-1.1 gene fragment is expressed in a pattern typical of mouse Thy-1, although it is more limited in its distribution. The results indicate the presence of multiple cis-acting regulators of Thy-1 gene expression that have changed in both their character and arrangement over the course of Thy-1 gene evolution.
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STORK PHILIPJ, WARHOL MICHAELJ, LOW MALCOLMJ, GOODMAN RICHARDH. Somatostatin Is Targeted to Gonadotrophic Secretory Granules in Transgenic Mice Expressing a Metallothionein-Somatostatin Fusion Gene. Ann N Y Acad Sci 1987. [DOI: 10.1111/j.1749-6632.1987.tb27183.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Sevarino K, Felix R, Banks C, Low M, Montminy M, Mandel G, Goodman R. Cell-specific processing of preprosomatostatin in cultured neuroendocrine cells. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)61143-3] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Affiliation(s)
- G Scangos
- Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218
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Goodman RH, Leiter A, Low MJ, Montminy MR, Tsukada T, Fink JS, Mandel G. Biosynthesis of pancreatic islet hormones. Hepatology 1987; 7:36S-41S. [PMID: 2879784 DOI: 10.1002/hep.1840070707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We have outlined the various strategies used to characterize the precursors of three pancreatic islet hormones--somatostatin, pancreatic polypeptide and VIP. In each case, isolation of the cDNA clones was facilitated by the use of gastrointestinal tissues that were extremely rich in specific mRNA. Characterization of the structures of the precursors is clearly only the first step in understanding the regulation of pancreatic hormone biosynthesis. It is likely that the availability of the cDNA clones will allow us to define the actual mechanisms underlying hormone production within the pancreas.
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Somatostatin is targeted to the regulated secretory pathway of gonadotrophs in transgenic mice expressing a metallothionein-somatostatin gene. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(18)66709-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Gordon K, Ruddle FH. Gene transfer into mouse embryos. DEVELOPMENTAL BIOLOGY (NEW YORK, N.Y. : 1985) 1986; 4:1-36. [PMID: 3078128 DOI: 10.1007/978-1-4613-2143-9_1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Gene transfer into the murine genome was accomplished nearly a decade ago by use of chimeras and teratocarcinomas; however, the low frequencies of transfer into the germ line and other difficulties stemming from mosaicism and karyotypic abnormalities in chimeric mice have limited the general usefulness of this procedure in achieving transformation in mammalian embryos. The introduction of cloned genes into teratocarcinoma cells, selection for a mutant phenotype, and transfer of those cells into mouse embryos holds some promise as a technique to employ mouse chimeras for gene transfer into mice. Infection with animal viruses and retroviral vectors provides another way to introduce exogenous DNA into mouse embryos. Infection with Mo-MuLV has been utilized to characterize the relationship between sites of integration and gene function in developing and adult mice. Gene transfer by microinjection of cloned recombinant DNA has been used by many laboratories for the transfer of DNAs into mouse embryos. The factors affecting transformation frequencies and sites of integration are unknown at present, although it seems that integration is not strictly mediated by homology-dependent events. Many genes have been introduced into mouse embryos by these procedures and many of these are expressed at high levels in appropriate tissues. No realistic possibility exists at the present time for the utilization of embryo gene transfer in the medical field for the correction of genetic defects for several reasons. First, in order to effectively provide "gene therapy" it would be necessary to determine the genotype of each recipient egg, a technical impossibility. The genetic diseases that would be amenable to germ line intervention are recessive diseases and there would be only a 25% chance of any one embryo derived from heterozygous parents being a homozygous recessive. Moreover, it would be impossible to distinguish the normal from abnormal embryos. Second, the frequencies of transformation are so low as to exclude work on human beings on ethical grounds. Third, the parameters effecting chromosomal integration sites and gene expression have not been fully characterized. Until it becomes experimentally possible to target the newly introduced DNA into expressable chromosomal sites and actively replace or supplement defective genes, the possibility of gene therapy through manipulation of embryos is remote. Yet, efforts to provide gene therapy in somatic tissues have been promising, leading to expression of a modified phenotype (Anderson, 1984). In contrast to embryo gene therapy, gene therapy in somatic tissues would not lead to germ line propagation of the manipulated genotype.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- K Gordon
- Integrated Genetics, Framingham, Massachusetts 01701
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