1
|
Codner GF, Erbs V, Loeffler J, Chessum L, Caulder A, Jullien N, Wells S, Birling MC, Teboul L. Universal Southern blot protocol with cold or radioactive probes for the validation of alleles obtained by homologous recombination. Methods 2021; 191:59-67. [PMID: 32599056 PMCID: PMC10790599 DOI: 10.1016/j.ymeth.2020.06.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 06/15/2020] [Accepted: 06/19/2020] [Indexed: 12/16/2022] Open
Abstract
The widespread availability of recombineered vectors and gene targeted embryonic stem cells from large-scale repositories facilitates the generation of mouse models for functional genetic studies. Southern blotting validates the structure of these targeted alleles produced by homologous recombination, as well as indicating any additional integrations of the vector into the genome. Traditionally this technique employs radioactively-labelled probes; however, there are many laboratories that are restricted in their use of radioactivity. Here, we present a widely applicable protocol for Southern blot analysis using cold probes and alternative procedures employing radioactive probes. Furthermore, the probes are designed to recognise standardised regions of gene-targeting cassettes and so represent universally applicable reagents for assessing allelic integrity.
Collapse
Affiliation(s)
- Gemma F Codner
- The Mary Lyon Centre, MRC Harwell Institute, Harwell Campus, Didcot, Oxon OX11 0RD, UK
| | - Valerie Erbs
- PHENOMIN-Institut Clinique de la Souris, CNRS, INSERM, Université de Strasbourg, Illkirch-Graffenstaden, Strasbourg 67404, France
| | - Jorik Loeffler
- The Mary Lyon Centre, MRC Harwell Institute, Harwell Campus, Didcot, Oxon OX11 0RD, UK
| | - Lauren Chessum
- The Mary Lyon Centre, MRC Harwell Institute, Harwell Campus, Didcot, Oxon OX11 0RD, UK
| | - Adam Caulder
- The Mary Lyon Centre, MRC Harwell Institute, Harwell Campus, Didcot, Oxon OX11 0RD, UK
| | - Nicolas Jullien
- Aix-Marseille University, CNRS, INP, Institut de Neurophysiopathologie, Marseille, France
| | - Sara Wells
- The Mary Lyon Centre, MRC Harwell Institute, Harwell Campus, Didcot, Oxon OX11 0RD, UK
| | - Marie-Christine Birling
- PHENOMIN-Institut Clinique de la Souris, CNRS, INSERM, Université de Strasbourg, Illkirch-Graffenstaden, Strasbourg 67404, France
| | - Lydia Teboul
- The Mary Lyon Centre, MRC Harwell Institute, Harwell Campus, Didcot, Oxon OX11 0RD, UK.
| |
Collapse
|
2
|
Angstenberger M, de Signori F, Vecchi V, Dall’Osto L, Bassi R. Cell Synchronization Enhances Nuclear Transformation and Genome Editing via Cas9 Enabling Homologous Recombination in Chlamydomonas reinhardtii. ACS Synth Biol 2020; 9:2840-2850. [PMID: 32916053 PMCID: PMC8011982 DOI: 10.1021/acssynbio.0c00390] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
![]()
In Chlamydomonas reinhardtii, the model organism
for eukaryotic green algae and plants, the processes of nuclear transformation
and genome editing in particular are still marked by a low level of
efficiency, and so intensive work is required in order to create and
identify mutants for the investigation of basic physiological processes,
as well as the implementation of biotechnological applications. In
this work, we show that cell synchronization during the stages of
the cell cycle, obtained from long-term cultivation under specific
growth conditions, greatly enhances the efficiency of transformation
and allows the identification of DNA repair mechanisms that occur
preferentially at different stages of the cell cycle. We demonstrate
that the transformation of synchronized cells at different times was
differentially associated with nonhomologous end joining (NHEJ) and/or
homologous recombination (HR), and makes it possible to knock-in specific
foreign DNA at the genomic nuclear location desired by exploiting
HR. This optimization greatly reduces the overall complexity of the
genome editing procedure and creates new opportunities for altering
genes and their products.
Collapse
Affiliation(s)
- Max Angstenberger
- Department of Biotechnology, University of Verona, Cà Vignal 1, Strada le Grazie 15, 31734 Verona, Italy
| | - Francesco de Signori
- Department of Biotechnology, University of Verona, Cà Vignal 1, Strada le Grazie 15, 31734 Verona, Italy
| | - Valeria Vecchi
- Department of Biotechnology, University of Verona, Cà Vignal 1, Strada le Grazie 15, 31734 Verona, Italy
| | - Luca Dall’Osto
- Department of Biotechnology, University of Verona, Cà Vignal 1, Strada le Grazie 15, 31734 Verona, Italy
| | - Roberto Bassi
- Department of Biotechnology, University of Verona, Cà Vignal 1, Strada le Grazie 15, 31734 Verona, Italy
| |
Collapse
|
3
|
Niikura K, Narita M, Narita M, Nakamura A, Okutsu D, Ozeki A, Kurahashi K, Kobayashi Y, Suzuki M, Suzuki T. Direct evidence for the involvement of endogenous beta-endorphin in the suppression of the morphine-induced rewarding effect under a neuropathic pain-like state. Neurosci Lett 2008; 435:257-62. [PMID: 18359165 DOI: 10.1016/j.neulet.2008.02.059] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2008] [Revised: 02/07/2008] [Accepted: 02/20/2008] [Indexed: 11/25/2022]
Abstract
Recent clinical studies have demonstrated that when opioids are used to control pain, psychological dependence is not a major problem. In this study, we further investigated the mechanisms that underlie the suppression of opioid reward under neuropathic pain in rodents. Sciatic nerve ligation suppressed a place preference induced by the selective mu-opioid receptor agonist [d-Ala(2), N-MePhe(4), Gly-ol(5)] enkephalin (DAMGO) and reduced both the increase in the level of extracellular dopamine by s.c. morphine in the nucleus accumbens and guanosine-5'-o-(3-[(35)S]thio) triphosphate ([(35)S]GTPgammaS) binding to membranes of the ventral tegmental area (VTA) induced by DAMGO. These effects were eliminated in mice that lacked the beta-endorphin gene. Furthermore, intra-VTA injection of a specific antibody to the endogenous mu-opioid peptide beta-endorphin reversed the suppression of the DAMGO-induced rewarding effect by sciatic nerve ligation in rats. These results provide molecular evidence that nerve injury results in the continuous release of endogenous beta-endorphin to cause the dysfunction of mu-opioid receptors in the VTA. This phenomenon could explain the mechanism that underlies the suppression of opioid reward under a neuropathic pain-like state.
Collapse
Affiliation(s)
- Keiichi Niikura
- Department of Toxicology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
4
|
Sitte N, Busch M, Mousa SA, Labuz D, Rittner H, Gore C, Krause H, Stein C, Schäfer M. Lymphocytes upregulate signal sequence-encoding proopiomelanocortin mRNA and beta-endorphin during painful inflammation in vivo. J Neuroimmunol 2007; 183:133-45. [PMID: 17223201 DOI: 10.1016/j.jneuroim.2006.11.033] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2006] [Revised: 11/15/2006] [Accepted: 11/29/2006] [Indexed: 11/29/2022]
Abstract
Proopiomelanocortin (POMC)-derived beta-endorphin1-31 (END) released from immune cells inhibits inflammatory pain. We examined the expression of END and POMC mRNA encoding the signal sequence required for entry of the nascent polypeptide into the regulated secretory pathway in lymphocytes of rats with inflamed hindpaws. Within 12 h of inflammation, END increased in popliteal lymph nodes and at 96 h the intraplantar neutralization of END exacerbated pain. Lymphocytes expressed POMC, END, and full-length POMC mRNA. Semi-nested PCR revealed 8-fold increased exon 2-3 spanning POMC mRNA. Thus, painful inflammation enhances signal sequence-encoding lymphocytic POMC mRNA needed for regulated secretion of functionally active END.
Collapse
Affiliation(s)
- Nicolle Sitte
- Department of Anesthesiology and Critical Care Medicine, Charité University Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12200 Berlin, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
5
|
Converse AD, Belur LR, Gori JL, Liu G, Amaya F, Aguilar-Cordova E, Hackett PB, McIvor RS. Counterselection and co-delivery of transposon and transposase functions for Sleeping Beauty-mediated transposition in cultured mammalian cells. Biosci Rep 2005; 24:577-94. [PMID: 16158196 DOI: 10.1007/s10540-005-2793-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Sleeping Beauty (SB) is a gene-insertion system reconstructed from transposon sequences found in teleost fish and is capable of mediating the transposition of DNA sequences from transfected plasmids into the chromosomes of vertebrate cell populations. The SB system consists of a transposon, made up of a gene of interest flanked by transposon inverted repeats, and a source of transposase. Here we carried out a series of studies to further characterize SB-mediated transposition as a tool for gene transfer to chromosomes and ultimately for human gene therapy. Transfection of mouse 3T3 cells, HeLa cells, and human A549 lung carcinoma cells with a transposon containing the neomycin phosphotransferase (NEO) gene resulted in a several-fold increase in drug-resistant colony formation when co-transfected with a plasmid expressing the SB transposase. A transposon containing a methotrexate-resistant dihydrofolate reductase gene was also found to confer an increased frequency of methotrexate-resistant colony formation when co-transfected with SB transposase-encoding plasmid. A plasmid containing a herpes simplex virus thymidine kinase gene as well as a transposon containing a NEO gene was used for counterselection against random recombinants (NEO+TK+) in medium containing G418 plus ganciclovir. Effective counterselection required a recovery period of 5 days after transfection before shifting into medium containing ganciclovir to allow time for transiently expressed thymidine kinase activity to subside in cells not stably transfected. Southern analysis of clonal isolates indicated a shift from random recombination events toward transposition events when clones were isolated in medium containing ganciclovir as well as G418. We found that including both transposon and transposase functions on the same plasmid substantially increased the stable gene transfer frequency in Huh7 human hepatoma cells. The results from these experiments contribute technical and conceptual insight into the process of transposition in mammalian cells, and into the optimal provision of transposon and transposase functions that may be applicable to gene therapy studies.
Collapse
Affiliation(s)
- Andrea D Converse
- Beckman Center for Transposon Research, Institute of Human Genetics, Department of Genetics, Cell Biology and Development, University of Minnesota, 6-160 Jackson Hall 321 Church Street S.E., Minneapolis, MN, 55455, USA
| | | | | | | | | | | | | | | |
Collapse
|
6
|
Franchini LF, Rubinstein M, Vivas L. Reduced sodium appetite and increased oxytocin gene expression in mutant mice lacking β-endorphin. Neuroscience 2003; 121:875-81. [PMID: 14580937 DOI: 10.1016/s0306-4522(03)00485-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Central opioid and oxytocinergic systems have been involved in the regulatory control of sodium appetite. In addition, previous studies support the existence of a functional interaction between opioid peptides and oxytocinergic pathways, and suggest that beta-endorphin neurons would modulate the activity of central oxytocinergic pathways, its pituitary secretion and sodium appetite. To investigate the role of this opioid peptide in the control of oxytocin (OT) synthesis and sodium appetite regulation we used mice with gene dosage-dependent variations in brain beta-endorphin content, expressing either 100%, 50%, or 0% of normal beta-endorphin content. Our results show that beta-endorphin knockout (KO) and heterozygous (HT) mutant mice consume approximately a 50% less 2% NaCl solution compared with wild type mice (WT), after furosemide and low sodium diet treatment. These data suggest that beta-endorphin may facilitate induced sodium appetite, giving new evidence about the role of beta-endorphin on sodium appetite behavior. Our data also indicate that OT mRNA levels evaluated by in situ hybridization significantly increased within the hypothalamic paraventricular nucleus of WT animals after induced sodium ingestion, giving support to former evidence indicating an inhibitory role for central OT in the control of sodium appetite. Moreover, beta-endorphin mutated mice have similar higher levels of OT mRNA expression after the different conditions analyzed: basal, control or experimental, compared with WT mice. Both control HT and KO mice showed higher OT mRNA expression levels than control WT group and these levels did not change after induced sodium intake. Taken together, our data suggest that the reduced sodium ingestion observed in beta-endorphin deficient mice could be due to a higher expression of the OT gene. This conclusion would support the hypothesis that OT inhibits sodium intake and provides new evidence about beta-endorphin modulation of OT synthesis and sodium appetite.
Collapse
Affiliation(s)
- L F Franchini
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, Casilla de Correo 389, 5000 Córdoba, Argentina
| | | | | |
Collapse
|
7
|
Vaanholt LM, Turek FW, Meerlo P. Beta-endorphin modulates the acute response to a social conflict in male mice but does not play a role in stress-induced changes in sleep. Brain Res 2003; 978:169-76. [PMID: 12834911 DOI: 10.1016/s0006-8993(03)02805-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Beta-endorphin is an endogenous opioid peptide that is released during stress and has been associated with many physiological functions. In this experiment beta-endorphin deficient mice were used to study the role of endorphins in the acute physiological and behavioral responses to a social conflict, as well as their role in social stress-induced changes in sleep. Adult male beta-endorphin deficient and wild type mice were subjected to the stress of a 1 h social conflict with an aggressive dominant conspecific. After the conflict, the beta-endorphin deficient mice had higher corticosterone levels but the peak increase in body temperature was not different from that in wild type animals. In fact, body temperature returned to baseline levels faster in the beta-endorphin deficient mice. During their interaction with the aggressive conspecific several of the beta-endorphin deficient mice showed clear signs of counter aggression whereas this was not seen in any of the wild type mice. Overall, the beta-endorphin deficient mice and wild type mice had fairly similar sleep patterns under baseline conditions and also showed similar amounts of NREM sleep, REM sleep and EEG slow-wave energy after the social conflict. In addition, no differences were found in the sleep patterns of mice that showed counter aggression and mice that did not. In conclusion, the results suggest that beta-endorphin modulates the acute endocrine, thermoregulatory and behavioral response to a social conflict but the data do not support a major role for beta-endorphin in the regulation of sleep or social stress-induced alterations in sleep.
Collapse
Affiliation(s)
- Lobke M Vaanholt
- Department of Neurobiology and Physiology, Northwestern University, Evanston, USA
| | | | | |
Collapse
|
8
|
Refojo D, Kovalovsky D, Young JI, Rubinstein M, Holsboer F, Reul JMHM, Low MJ, Arzt E. Increased splenocyte proliferative response and cytokine production in beta-endorphin-deficient mice. J Neuroimmunol 2002; 131:126-34. [PMID: 12458044 DOI: 10.1016/s0165-5728(02)00268-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We used beta-endorphin-deficient mice as a novel approach to confirm the physiological role that opioid peptides play in the development or regulation of the immune system. We found that mice lacking beta-endorphin possessed an enhanced immune response, measured in terms of splenocyte proliferation and interleukin (IL)-2 mRNA levels, in vitro production of the splenic macrophage inflammatory cytokines IL-6 and Tumor Necrosis Factor (TNF)-alpha and plasma IL-6 following lipopolysaccharide (LPS) administration. beta-Endorphin-deficient mice had attenuated increases of plasma ACTH and corticosterone levels in response to LPS. These results are consistent with a postulated inhibitory role of endogenous beta-endorphin on the immune system at multiple levels.
Collapse
Affiliation(s)
- Damian Refojo
- Laboratorio de Fisiología y Biología Molecular, Departamento de Biología, Facultad de Ciencias Exactas y Naturales (FCEN), Universidad de Buenos Aires, Ciudad Universitaria, Pabellon II, C1428EHA, Buenos Aires, Argentina
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Low MJ, Otero-Corchon V, Parlow AF, Ramirez JL, Kumar U, Patel YC, Rubinstein M. Somatostatin is required for masculinization of growth hormone-regulated hepatic gene expression but not of somatic growth. J Clin Invest 2001; 107:1571-80. [PMID: 11413165 PMCID: PMC200191 DOI: 10.1172/jci11941] [Citation(s) in RCA: 133] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Pulsatile growth hormone (GH) secretion differs between males and females and regulates the sex-specific expression of cytochrome P450s in liver. Sex steroids influence the secretory dynamics of GH, but the neuroendocrine mechanisms have not been conclusively established. Because periventricular hypothalamic somatostatin (SST) expression is greater in males than in females, we generated knockout (Smst(-/-)) mice to investigate whether SST peptides are necessary for sexually differentiated GH secretion and action. Despite marked increases in nadir and median plasma GH levels in both sexes of Smst(-/-) compared with Smst(+/+) mice, the mutant mice had growth curves identical to their sibling controls and retained a normal sexual dimorphism in weight and length. In contrast, the liver of male Smst(-/-) mice was feminized, resulting in an identical profile of GH-regulated hepatic mRNAs between male and female mutants. Male Smst(-/-) mice show higher expression of two SST receptors in the hypothalamus and pituitary than do females. These data indicate that SST is required to masculinize the ultradian GH rhythm by suppressing interpulse GH levels. In the absence of SST, male and female mice exhibit similarly altered plasma GH profiles that eliminate sexually dimorphic liver function but do not affect dimorphic growth.
Collapse
Affiliation(s)
- M J Low
- Vollum Institute, Oregon Health & Science University, Portland, Oregon 97201, USA.
| | | | | | | | | | | | | |
Collapse
|
10
|
Abstract
Vascular endothelial growth factor (VEGF) is required for endothelial cell differentiation, vasculogenesis, and normal glomerular vascularization. To examine whether VEGF plays a role as a chemoattractant for the developing kidney vasculature, avascular metanephric kidneys from rat embryos (E14) were cocultured with endothelial cells. To determine whether VEGF directly provides chemoattractive guidance for migration, we examined migration of endothelial cells toward VEGF-coated beads. Mouse glomerular endothelial cells expressing beta-galactosidase (MGEC) were isolated from Flk-1(+/-) heterozygous mice and passaged 4-12 times. Upon 24 h culture on collagen I gels MGEC formed a lattice or capillary-like network. Embryonic metanephroi were cocultured with MGEC on collagen I gels for 1-6 days in defined media, stained for beta-galactosidase, and examined by light microscopy. Metanephric organs induced a rearrangement of the endothelial cell lattice and attracted MGEC. MGEC invaded the metanephric organs forming capillary-like structures within and surrounding the forming nephrons. This process was accelerated and amplified by low oxygen (3% O(2)) and was prevented by anti-VEGF neutralizing antibodies. MGECs migrated toward VEGF-coated beads, whereas PBS-coated beads did not alter MGEC networks. We conclude that VEGF produced by the differentiating nephrons acts as a chemoattractant providing spatial direction to developing capillaries toward forming nephrons during metanephric development in vitro.
Collapse
Affiliation(s)
- A Tufró
- Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, Virginia 22908-0386, USA
| |
Collapse
|
11
|
Affiliation(s)
- M D Hayward
- Vollum Institute, Oregon Health Sciences University, Portland 97201, USA
| | | |
Collapse
|
12
|
Rubinstein M, Mogil JS, Japón M, Chan EC, Allen RG, Low MJ. Absence of opioid stress-induced analgesia in mice lacking beta-endorphin by site-directed mutagenesis. Proc Natl Acad Sci U S A 1996; 93:3995-4000. [PMID: 8633004 PMCID: PMC39474 DOI: 10.1073/pnas.93.9.3995] [Citation(s) in RCA: 238] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
A physiological role for beta-endorphin in endogenous pain inhibition was investigated by targeted mutagenesis of the proopiomelanocortin gene in mouse embryonic stem cells. The tyrosine codon at position 179 of the proopiomelanocortin gene was converted to a premature translational stop codon. The resulting transgenic mice display no overt developmental or behavioral alterations and have a normally functioning hypothalamic-pituitary-adrenal axis. Homozygous transgenic mice with a selective deficiency of beta-endorphin exhibit normal analgesia in response to morphine, indicating the presence of functional mu-opiate receptors. However, these mice lack the opioid (naloxone reversible) analgesia induced by mild swim stress. Mutant mice also display significantly greater nonopioid analgesia in response to cold water swim stress compared with controls and display paradoxical naloxone-induced analgesia. These changes may reflect compensatory upregulation of alternative pain inhibitory mechanisms.
Collapse
Affiliation(s)
- M Rubinstein
- Vollum Institute for Advanced Biomedical Research, Oregon Health Sciences University, Portland 97201, USA
| | | | | | | | | | | |
Collapse
|
13
|
Mogil JS, Sternberg WF, Marek P, Sadowski B, Belknap JK, Liebeskind JC. The genetics of pain and pain inhibition. Proc Natl Acad Sci U S A 1996; 93:3048-55. [PMID: 8610166 PMCID: PMC39759 DOI: 10.1073/pnas.93.7.3048] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The present review summarizes the current state of knowledge about the genetics of pain-related phenomena and illustrates the scope and power of genetic approaches to the study of pain. We focus on work performed in our laboratories in Jastrzebiec, Poland; Portland, OR; and Los Angeles, which we feel demonstrates the continuing usefulness of classical genetic approaches, especially when used in combination with newly available molecular genetic techniques.
Collapse
Affiliation(s)
- J S Mogil
- Department of Psychology, University of California, Los Angeles, 90095-1563, USA
| | | | | | | | | | | |
Collapse
|
14
|
Abstract
Gene disruption technology in mammals, by homologous recombination in embryonic stem cells, is a powerful method to manipulate the mouse germ line. In the past decade it has produced a wealth of knowledge concerning neuronal development, neurodegenerative disorders and the roles of oncogenes, Hox genes and growth factors during development. A surprising variety of genes, however, have given unexpected and disappointing results. A gene/function redundancy theory proposed by many investigators to explain the unexpected results has been supported in certain cases by the generation of double knockout mice. Modification of the basic technology now allows the investigators to carry out a variety of manipulations including conditional or tissue-specific knockouts. This may provide a better opportunity in the future for the gene therapy approach to correct the genetic disorder.
Collapse
Affiliation(s)
- B S Shastry
- Eye Research Institute, Oakland University, Rochester, Michigan 48309-4401, USA
| |
Collapse
|
15
|
Bronson SK, Smithies O. Altering mice by homologous recombination using embryonic stem cells. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(18)46959-1] [Citation(s) in RCA: 139] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
|
16
|
Abstract
Behavioral and pharmacological responses of selectively bred and inbred rodent lines have been analyzed to elucidate many features of drug sensitivity and the adverse effects of drugs, the underlying mechanisms of drug tolerance and dependence, and the motivational states underlying drug reward and aversion. Genetic mapping of quantitative trait loci (QTLs) has been used to identify provisional chromosomal locations of genes influencing such pharmacological responses. Recent advances in transgenic technology, representational difference analysis, and other molecular methods now make feasible the positional cloning of QTLs that influence sensitivity to drugs of abuse. This marks a new period of synthesis in pharmacogenetic research, in which networks of drug-related behaviors, their underlying pharmacological, physiological, and biochemical mechanisms, and particular genomic regions of interest are being identified.
Collapse
Affiliation(s)
- J C Crabbe
- Research Service, Veterans Administration (VA) Medical Center, Portland, OR 97201
| | | | | |
Collapse
|
17
|
Affiliation(s)
- K R Thomas
- Howard Hughes Medical Institute, University of Utah School of Medicine, Salt Lake City 84112
| |
Collapse
|