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Zhao X, Bhattacharyya A. Human Models Are Needed for Studying Human Neurodevelopmental Disorders. Am J Hum Genet 2018; 103:829-857. [PMID: 30526865 DOI: 10.1016/j.ajhg.2018.10.009] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 10/09/2018] [Indexed: 12/19/2022] Open
Abstract
The analysis of animal models of neurological disease has been instrumental in furthering our understanding of neurodevelopment and brain diseases. However, animal models are limited in revealing some of the most fundamental aspects of development, genetics, pathology, and disease mechanisms that are unique to humans. These shortcomings are exaggerated in disorders that affect the brain, where the most significant differences between humans and animal models exist, and could underscore failures in targeted therapeutic interventions in affected individuals. Human pluripotent stem cells have emerged as a much-needed model system for investigating human-specific biology and disease mechanisms. However, questions remain regarding whether these cell-culture-based models are sufficient or even necessary. In this review, we summarize human-specific features of neurodevelopment and the most common neurodevelopmental disorders, present discrepancies between animal models and human diseases, demonstrate how human stem cell models can provide meaningful information, and discuss the challenges that exist in our pursuit to understand distinctively human aspects of neurodevelopment and brain disease. This information argues for a more thoughtful approach to disease modeling through consideration of the valuable features and limitations of each model system, be they human or animal, to mimic disease characteristics.
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Affiliation(s)
- Xinyu Zhao
- Waisman Center, School of Medicine and Public Health, University of Wisconsin-Madison, Madison WI 53705, USA; Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin-Madison, Madison WI 53705, USA.
| | - Anita Bhattacharyya
- Waisman Center, School of Medicine and Public Health, University of Wisconsin-Madison, Madison WI 53705, USA; Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison WI 53705, USA.
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2
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Vásquez-Navarrete J, Martínez AD, Ory S, Baéz-Matus X, González-Jamett AM, Brauchi S, Caviedes P, Cárdenas AM. RCAN1 Knockdown Reverts Defects in the Number of Calcium-Induced Exocytotic Events in a Cellular Model of Down Syndrome. Front Cell Neurosci 2018; 12:189. [PMID: 30034324 PMCID: PMC6043644 DOI: 10.3389/fncel.2018.00189] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 06/12/2018] [Indexed: 12/15/2022] Open
Abstract
In humans, Down Syndrome (DS) is a condition caused by partial or full trisomy of chromosome 21. Genes present in the DS critical region can result in excess gene dosage, which at least partially can account for DS phenotype. Although regulator of calcineurin 1 (RCAN1) belongs to this region and its ectopic overexpression in neurons impairs transmitter release, synaptic plasticity, learning and memory, the relative contribution of RCAN1 in a context of DS has yet to be clarified. In the present work, we utilized an in vitro model of DS, the CTb neuronal cell line derived from the brain cortex of a trisomy 16 (Ts16) fetal mouse, which reportedly exhibits acetylcholine release impairments compared to CNh cells (a neuronal cell line established from a normal littermate). We analyzed single exocytotic events by using total internal reflection fluorescence microscopy (TIRFM) and the vesicular acetylcholine transporter fused to the pH-sensitive green fluorescent protein (VAChT-pHluorin) as a reporter. Our analyses showed that, compared with control CNh cells, the trisomic CTb cells overexpress RCAN1, and they display a reduced number of Ca2+-induced exocytotic events. Remarkably, RCAN1 knockdown increases the extent of exocytosis at levels comparable to those of CNh cells. These results support a critical contribution of RCAN1 to the exocytosis process in the trisomic condition.
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Affiliation(s)
- Jacqueline Vásquez-Navarrete
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Agustín D Martínez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Stéphane Ory
- Centre National de la Recherche Scientifique (CNRS UPR 3212), Institut des Neurosciences Cellulaires et Intégratives (INCI), Strasbourg, France
| | - Ximena Baéz-Matus
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Arlek M González-Jamett
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Sebastián Brauchi
- Department of Physiology, Faculty of Medicine, Universidad Austral de Chile, Valdivia, Chile
| | - Pablo Caviedes
- Programa de Farmacología Molecular y Clínica, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Centro de Biotecnología y Bioingeniería (CeBiB), Departamento de Ingeniería Química, Biotecnología y Materiales, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile
| | - Ana M Cárdenas
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
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3
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Sawaguchi T, Franco P, Kadhim H, Groswasser J, Sottiaux M, Nishida H, Sawaguchi A, Kahn A. Investigation into the correlation in SIDS victims between Alzheimer precursor protein A4 in the brainstem and sleep apnea. PATHOPHYSIOLOGY 2004. [DOI: 10.1016/j.pathophys.2004.01.004] [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] Open
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4
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Sawaguchi T, Patricia F, Kadhim H, Groswasser J, Sottiaux M, Nishida H, Sawaguchi A, Kahn A. Investigation into the correlation in SIDS victims between Alzheimer precursor protein A4 in the brainstem and sleep apnea. Early Hum Dev 2003; 75 Suppl:S21-30. [PMID: 14693388 DOI: 10.1016/j.earlhumdev.2003.08.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Recently, the appearance of beta-amyloid precursor protein (APP) has been demonstrated in the neonatal brain following hypoxic-ischaemic injury. As chronic hypoxia is one of the favoured theories of causation in the sudden infant death syndrome (SIDS), the correlation between APP in the brainstem and sleep apnea in SIDS was investigated. MATERIALS AND METHODS Among 27,000 infants studied prospectively to characterize their sleep-wake behavior, 38 infants died under 6 months of age, which included 26 cases of SIDS. All the infants had been recorded during one night in a pediatric sleep laboratory, some 3 to 12 weeks before death. The frequency and duration of sleep apnea were analyzed. The brainstem material was collected and immunohistochemistry with anti-Alzheimer precursor protein A4 (APP) was carried out. The density of APP-positive elements was measured semi-quantitatively. Correlation analyses were carried out between the density of APP-positive elements and the data on sleep apnea. RESULTS No correlation was found. CONCLUSION No correlation between pathological data of APP and physiological data of sleep apnea was not in agreement with the association of sleep apnea in pathophysiology of SIDS.
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Affiliation(s)
- Toshiko Sawaguchi
- Department of Legal Medicine, Tokyo Women's Medical University School of Medicine, 8-1 Kawada-cho, Shinjuku, Tokyo 162-8666, Japan.
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5
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Triarhou LC. Histochemical properties of intrastriatal mesencephalic grafts. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2003; 517:43-61. [PMID: 12580306 DOI: 10.1007/978-1-4615-0699-7_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Lazaros C Triarhou
- Department of Pathology and Laboratory Medicine, Division of Neuropathology, Medical Science Building A142, Indiana University Medical Center, 635 Barnhill Drive, Indianapolis, Indiana 46202-5120, USA
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6
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Triarhou LC. Biology and pathology of the Weaver mutant mouse. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2003; 517:15-42. [PMID: 12580305 DOI: 10.1007/978-1-4615-0699-7_2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Affiliation(s)
- Lazaros C Triarhou
- Department of Pathology and Laboratory Medicine, Division of Neuropathology, Medical Science Building A142, Indiana University Medical Center, 635 Barnhill Drive, Indianapolis, Indiana 46202-5120, USA
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7
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Abstract
Neural transplantation provides a powerful novel technique for investigating the neurobiological basis and potential strategies for repair of a variety of neurodegenerative conditions. The present review considers applications of this technique to dementia. After a general introduction (section 1), attempts to replace damaged neural systems by transplantation are considered in the context of distinct animal models of dementia. These include grafting into aged animals (section 2), into animals with neurotransmitter-selective lesions of subcortical nuclei, in particular involving basal forebrain cholinergic systems (section 3), and into animals with non-specific lesions of neocortical and hippocampal systems (section 4). The next section considers the alternative use of grafts as a source of growth/trophic factors to inhibit degeneration and promote regeneration in the aged brain (section 5). Finally, a number of recent studies have employed transplanted tissues to model and study the neurodegenerative processes associated with ageing and Alzheimer's disease taking place within the transplant itself (section 6). It is concluded (section 7) that although neural transplantation does not offer any immediate prospect of therapeutic repair in clinical dementia, the technique does offer a powerful neurobiological tool for studying the neuropathological processes involved in both spontaneous degeneration and specific diseases of ageing. New understandings derived from neural transplantation may be expected to lead to rational development of novel strategies to inhibit the neurodegenerative process and to promote regeneration in the aged brain.
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Affiliation(s)
- S. B. Dunnett
- Department of Experimental Psychology, University of Cambridge, Downing Street, Cambridge CB2 3EB, UK
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8
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McVeigh KE, Mallee JJ, Lucente A, Barnoski BL, Wu S, Berry GT. Murine chromosome 16 telomeric region, homologous with human chromosome 21q22, contains the osmoregulatory Na(+)/myo-inositol cotransporter (SLC5A3) gene. CYTOGENETICS AND CELL GENETICS 2000; 88:153-8. [PMID: 10773690 DOI: 10.1159/000015509] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The murine Na(+)/myo-inositol cotransporter (SLC5A3) gene (Slc5a3) was cloned, the restriction sites mapped, and the coding region sequenced. Similar to other mammalian counterparts, including human, the gene has a single coding exon, with an open reading frame of 2.2 kb. The predicted protein of 718 amino acids is also highly conserved, compared to other mammalian homologs. Using fluorescence in situ hybridization, Slc5a3 was localized to the telomeric region of mouse chromosome 16, which is syntenic to human chromosome 21q22. An increased Slc5a3 copy number may explain the increased levels of myo-inositol in the brains of trisomy 16 mice and the increased rate of transport of myo-inositol into cultured neurons derived from trisomy 16 mice.
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Affiliation(s)
- K E McVeigh
- Department of Pediatrics, The Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-4399, USA
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9
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Abstract
Five intersubspecific backcrosses and an intercross were used to establish a sex-averaged recombinational map spanning 56 cM across most of mouse Chromosome 16 (Chr 16). A total of 123 markers were ordered using an interval mapping approach to identify 425 recombination sites in a collection of 1154 meioses from 1155 progeny generated in the six crosses. The markers include the 10 "classic" Chr 16 reference markers, 26 additional genes or transcripts including two phenotypic markers (Pit1dw and Kcnj6wv), and 87 simple sequence length polymorphisms (SSLPs). One set of monozygotic twins was detected among the 304 meioses mapped to highest resolution. The reference markers and SSLPs allow the map to be well integrated with existing maps of Chr 16. The average distance between crossover sites is less than 500 kb for most chromosomes, making this collection of recombinant chromosomes useful as a binning and ordering resource for YAC-based physical map assembly on Chr 16.
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Affiliation(s)
- R H Reeves
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
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10
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Sumarsono SH, Wilson TJ, Tymms MJ, Venter DJ, Corrick CM, Kola R, Lahoud MH, Papas TS, Seth A, Kola I. Down's syndrome-like skeletal abnormalities in Ets2 transgenic mice. Nature 1996; 379:534-7. [PMID: 8596630 DOI: 10.1038/379534a0] [Citation(s) in RCA: 151] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Expression of Ets2, a proto-oncogene and transcription factor, occurs in a variety of cell types. During murine development it is highly expressed in newly forming cartilage, including in the skull precursor cells and vertebral primordia. Ets2 is located on human chromosome 21 (ref. 8) and is overexpressed in Down's syndrome (trisomy 21). Here we generate transgenic mice to investigate the consequences of overexpression of Ets2. We find that mice with less than 2-fold Ets2 overexpression in particular organs develop neurocranial, viscerocranial and cervical skeletal abnormalities. These abnormalities have similarities with the skeletal anomalies found in trisomy-16 mice and humans with Down's syndrome, in which the gene dosage of Ets2 is increased. Our results indicate that Ets2 has a role in skeletal development and implicate the overexpression of Ets2 in the genesis of some skeletal abnormalities that occur in Down's syndrome.
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Affiliation(s)
- S H Sumarsono
- Molecular Genetics and Development Group, Monash University, Monash Medical Centre, Clayton, Victoria, Australia
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11
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Frederiksen K, Thorpe A, Richards SJ, Waters J, Dunnett SB, Sandberg BE. Immortalized neural cells from trisomy 16 mice as models for Alzheimer's disease. Ann N Y Acad Sci 1996; 777:415-20. [PMID: 8624123 DOI: 10.1111/j.1749-6632.1996.tb34455.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The trisomy 16 mouse (Ts16) is a general accepted animal model for both Downs syndrome (DS) and Alzheimer's Disease (AD). However, the efficacy of this model is severely hampered by the fact that Ts16 is lethal after about 18-20 days of gestation. Chimeras, long-term tissue culture and neural transplantation of Ts16 material have previously been used to overcome this limitation presented by death in utero of the Ts16. In this paper we describe a new strategy to overcome this limitation, i.e. immortalization of primary cells from Ts16 mice with retrovirus-mediated gene transfer of a temperature sensitive immortalizing oncogene. By this method we have obtained a total of 21 stable cell lines from Ts16 hippocampus, Ts16 cortex, normal hippocampus, and normal cortex. So far, two of the cell lines have been karyotyped and as expected, the cell line immortalized from Ts16 embryos has retained three copies of chromosome 16. We are currently characterizing these cell lines with respect to expression of APP, T-antigen, Nestin, GFAP, NF and Map-2. Moreover, the processing and secretion of APP fragments are being investigated by immunoblotting. In summary, we have immortalized CNS cells from Ts16 mice and we expect that these cell lines will be useful as in vitro and in vivo models for studying various aspects of the pathology of Alzheimer's disease.
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Affiliation(s)
- K Frederiksen
- Pharmacological Research, H. Lundbeck A/S, Copenhagen-Valby, Denmark
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12
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Reeves RH, Irving NG, Moran TH, Wohn A, Kitt C, Sisodia SS, Schmidt C, Bronson RT, Davisson MT. A mouse model for Down syndrome exhibits learning and behaviour deficits. Nat Genet 1995; 11:177-84. [PMID: 7550346 DOI: 10.1038/ng1095-177] [Citation(s) in RCA: 684] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Trisomy 21 or Down syndrome (DS) is the most frequent genetic cause of mental retardation, affecting one in 800 live born human beings. Mice with segmental trisomy 16 (Ts65Dn mice) are at dosage imbalance for genes corresponding to those on human chromosome 21q21-22.3--which includes the so-called DS 'critical region'. They do not show early-onset of Alzheimer disease pathology; however, Ts65Dn mice do demonstrate impaired performance in a complex learning task requiring the integration of visual and spatial information. The reproducibility of this phenotype among Ts65Dn mice indicates that dosage imbalance for a gene or genes in this region contributes to this impairment. The corresponding dosage imbalance for the human homologues of these genes may contribute to cognitive deficits in DS.
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Affiliation(s)
- R H Reeves
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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13
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Seipp S, Buselmaier W. Isolation of glyceraldehyde 3-phosphate dehydrogenase (Gapdh) cDNA from the distal half of mouse chromosome 16: further indication of a link between Alzheimer's disease and glycolysis. Neurosci Lett 1994; 182:91-4. [PMID: 7891898 DOI: 10.1016/0304-3940(94)90214-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The amyloid precursor protein (APP), which is localized on both human chromosome 21 and its murine counterpart, chromosome 16 and which is involved in the formation of deposits in Alzheimer's disease, could be shown to bind effectively to a glytolytic enzyme: rat glyceraldehyde 3-phosphate dehydrogenase (Gapdh). We report here the isolation of a cDNA of murine Gapdh from mouse chromosome 16 (MMU16) originating from microclones of the distal part of MMU16 and the use of homologous genomic DNA sequences to further screen a cDNA phage library. The cDNA was sequenced, confirmed by polymerase chain reaction following reverse transcriptase (RT-PCR) and the open reading frame was expressed in vitro. The possible localization of Gapdh on MMU16--which may provide a mouse model for Down's syndrome and Alzheimer's disease--may lead to new insights into glycolysis and its role in the two syndromes.
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Affiliation(s)
- S Seipp
- Institut für Humangenetik und Anthropologie, Universität Heidelberg, Germany
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14
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Lane NJ, Balbo A, Stoll J, Rapoport SI. Long-term intracerebral transplants of fetal hippocampus from mouse trisomy 16, a model for Down's syndrome (trisomy 21), do not exhibit Alzheimer's disease neuropathology by ultrastructural criteria . Tissue Cell 1994; 26:477-88. [PMID: 8091421 DOI: 10.1016/0040-8166(94)90001-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Murine trisomy 16 (Ts16) is an animal model for Down's syndrome (human trisomy 21), because mouse chromosome 16 is genetically homologous to human chromosome 21. Down's syndrome patients, older than 35 years, demonstrate the neuropathological and neurochemical defects characteristic of Alzheimer's disease and Ts16 mouse fetuses exhibit phenotypic abnormalities similar to those in Down's syndrome fetuses. Trisomic mouse fetuses, however, die in utero, and so do not survive long enough for their brains to develop the degenerative changes of aging. This can be overcome by grafting the fetal Ts16 hippocampus (an early site for the development of the pathological features characteristic of Alzheimer's disease), into the cerebral ventricle or striatum of a normal adult mouse host. We have made such transplants, which have survived for up to 12 months. Examining these grafts ultrastructurally at various stages from 1 to 12 months, and comparing them with normal control grafts, reveals no structural difference that could be deemed characteristic of Alzheimer disease; no neurofibrillary tangle or senile plaque was observed. These observations, together with the normal structure of the neuronal organelles in trisomic hippocampal tissue, suggest that trisomic mouse grafts are not a useful model for Alzheimer's disease, despite earlier reports to the contrary.
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Affiliation(s)
- N J Lane
- Department of Zoology, University of Cambridge, UK
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15
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Solà C, Mengod G, Low WC, Norton J, Ghetti B, Palacios JM, Triarhou LC. Regional distribution of amyloid beta-protein precursor, growth-associated phosphoprotein-43 and microtubule-associated protein 2 messenger RNAs in the nigrostriatal system of normal and Weaver mutant mice and effects of ventral mesencephalic grafts. Eur J Neurosci 1993; 5:1442-54. [PMID: 8287193 DOI: 10.1111/j.1460-9568.1993.tb00212.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Using in situ hybridization histochemistry with [32P]oligonucleotide probes, we studied the cellular localization of RNA transcripts for amyloid beta-protein precursor (beta APP), growth-associated phosphoprotein-43 (GAP-43) and microtubule-associated protein 2 (MAP2) in the mesostriatal system of normal (+/+) and weaver (wv/wv) mutant mice, which lose mesencephalic dopamine neurons. In addition, expression of the same messages was studied in ventral mesencephalic cell suspensions transplanted to the weaver striatum. Transcripts encoding GAP-43, MAP2 and isoforms beta APP695, beta APP714 and beta APP751 were present in normal substantia nigra and progressively reduced in weaver substantia nigra; such a reduction was correlated with dopamine neuron loss. The survival of dopamine neurons in unilateral intrastriatal grafts was documented by methamphetamine-induced rotational asymmetry tests and by tyrosine hydroxylase immunocytochemistry. High hybridization signals were obtained for GAP-43, MAP2, beta APP695, beta APP714 and beta APP751 RNA transcripts in the grafted tissue; the beta APP770 species--normally seen in striatum and not substantia nigra--was not expressed in the grafts, but it was present in the recipient striatum. Following immunocytochemical labelling with antibodies, GAP-43 and MAP2 immunoreactivities were seen in cell processes in the grafts and surrounding tissue, whereas beta APP immunoreactivity was mainly found in grafted cell bodies. These results suggest that the transplanted mesencephalic cells mature very similarly to those in the normal substantia nigra, expressing different mRNAs that are normally present in the ventral midbrain and which are reduced in the weaver mutant as a consequence of dopamine neuron loss.
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Affiliation(s)
- C Solà
- Preclinical Research, Sandoz Pharma AG, Basel, Switzerland
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16
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Solà C, Mengod G, Ghetti B, Palacios JM, Triarhou LC. Regional distribution of the alternatively spliced isoforms of beta APP RNA transcript in the brain of normal, heterozygous and homozygous weaver mutant mice as revealed by in situ hybridization histochemistry. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1993; 17:340-6. [PMID: 8510506 DOI: 10.1016/0169-328x(93)90020-p] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The cellular localization of amyloid beta-protein precursor (beta APP) RNA transcripts was studied by in situ hybridization histochemistry in normal, heterozygous and homozygous weaver (wv) mutant mice, which lose midbrain dopamine (DA) neurons, cerebellar granule cells, and Purkinje cells. The beta APP gene is located at the distal end of mouse chromosome (MMU) 16, on which the wv locus has been assigned as well. Transcripts encoding isoforms beta APP695, beta APP714 and beta APP751 were present in several different brain areas of normal (+/+) mice, including hippocampus, substantia nigra (SN) pars compacta and cerebellum. The same transcripts were progressively reduced in homozygous weaver (wv/wv) SN, in correlation with DA neuron loss. The beta APP770 species--normally seen in striatum and not SN--was present in the mutant striatum. There were not any obvious changes in beta APP expression in the nigrostriatal system of weaver heterozygotes (wv/+). In normal cerebellum, Purkinje cells showed very high levels of hybridization signal for beta APP695, beta APP714 and beta APP751 RNA transcripts, and a moderate signal for the beta APP770 species. In weaver heterozygotes and homozygotes, Purkinje cells, which are typically not arranged in a monolayer, showed strong hybridization signal. No changes in beta APP mRNAs were observed in brain areas other than the cerebellum and ventral midbrain of weaver mutants. These findings suggest that the decreased beta APP gene expression seen in the cerebellum and SN of weaver mutants most likely represents an epiphenomenon of the regional nerve cell loss and, therefore, the wv gene defect on MMU 16 does not seem to influence the expression of the closely linked beta APP gene in brain areas outside the nigrostriatal pathway and cerebellar cortex.
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Affiliation(s)
- C Solà
- Preclinical Research, Sandoz Pharma AG, Basel, Switzerland
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17
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Oyama F, Shimada H, Oyama R, Titani K, Ihara Y. A novel correlation between the levels of beta-amyloid protein precursor and tau transcripts in the aged human brain. J Neurochem 1992; 59:1117-25. [PMID: 1494902 DOI: 10.1111/j.1471-4159.1992.tb08354.x] [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: 12/27/2022]
Abstract
beta-Amyloid protein precursor (APP) and tau are implicated in the pathogenesis of Alzheimer's disease. We quantified the levels of APP and tau transcripts in the three cortical regions of 38 aged human brains obtained from consecutive autopsied patients. The level of APP mRNA was directly proportional to that of tau mRNA to a remarkable extent, suggesting coordinate expression of the APP and tau genes, whereas much weaker correlations were noted among mRNAs encoding other neuronal proteins. From the previous data on the differential expression of APP and tau mRNAs, the levels of APP-751 and -695 mRNAs were calculated and found to be proportional to those of four-repeat and three-repeat tau mRNAs, respectively, whereas that of APP-770 mRNA was rather constant. These results suggest that the mRNA concentrations of APP isoforms are linked to those of tau isoforms in the aged human brain.
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Affiliation(s)
- F Oyama
- Division of Biomedical Polymer Science, School of Medicine, Fujita Health University, Aichi, Japan
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18
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Affiliation(s)
- R H Reeves
- Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
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19
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Weaver Gene Expression in Central Nervous System. ACTA ACUST UNITED AC 1992. [DOI: 10.1016/b978-0-12-185267-2.50020-9] [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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MacDonald G, Chu ML, Cox DR. Fine structure physical mapping of the region of mouse chromosome 10 homologous to human chromosome 21. Genomics 1991; 11:317-23. [PMID: 1837533 DOI: 10.1016/0888-7543(91)90138-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Comparative mapping of human and mouse DNA for regions of genetic homology between human Chromosome 21 and the mouse genome is of interest because of the possibility of developing mouse models of human trisomy 21 (Down syndrome), understanding chromosome evolution, and isolating novel sequences conserved between the two species. At least two mouse chromosomes are known to carry sequences homologous to those on human Chromosome 21: mouse Chromosome 16 (D21S16h, D21S13h, D21S52h, App, Sod-1, Mx-1, Ets-2, Prgs,Ifnar) and mouse Chromosome 17 (D21S56h, Crya-1, and Cbs). Recently, five additional genes have been mapped within region 21q22 of human Chromosome 21:PFKL, CD18, COL6A1, COL6A2, and S100B. To assign these sequences to specific mouse chromosomes, we used human cDNA probes for COL6A1, COL6A2, CD18, and PFKL and a rat brain cDNA probe for S100B in conjunction with a panel of seven Chinese hamster-mouse somatic cell hybrids segregating mouse chromosomes. The specific chromosome complements of the hybrid cell lines and the presence or absence of hybridizing mouse sequences in their DNAs allow us to assign all five sequences to mouse Chromosome 10, with the assignment of Pfkl reported here for the first time. Analysis of genomic mouse DNA fragments produced by digestion with rare-cutting restriction enzymes and separated using pulsed-field gel electrophoresis allows us to construct a fine-structure physical map of two segments of the region of Chromosome 10 containing these five markers. The five loci span at least 1900 kb of mouse DNA and are consistent with the human order: Pfkl-Cd-18-Col6a-1-Col6a-2-S100b.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- G MacDonald
- Department of Pediatrics, University of California, San Francisco 94143
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21
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Richards SJ. The neuropathology of Alzheimer's disease investigated by transplantation of mouse trisomy 16 hippocampal tissues. Trends Neurosci 1991; 14:334-8. [PMID: 1721736 DOI: 10.1016/0166-2236(91)90157-p] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
This article evaluates the novel application of neural transplantation as a model for studying the neuropathological events associated with Alzheimer's disease and those that have subsequently also been observed in Trisomy 21 (Down syndrome).
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Affiliation(s)
- S J Richards
- Dept of Medicine, Addenbrooke's Hospital, Cambridge, UK
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22
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Fisher S, Gearhart JD, Oster-Granite ML. Expression of the amyloid precursor protein gene in mouse oocytes and embryos. Proc Natl Acad Sci U S A 1991; 88:1779-82. [PMID: 1900367 PMCID: PMC51108 DOI: 10.1073/pnas.88.5.1779] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The amyloid precursor protein (APP) is thought to be processed aberrantly to yield the major constituent of the amyloid plaques observed in the brains of patients with Alzheimer disease and Down syndrome. However, the gene encoding APP is expressed widely in normal human tissues and in adult and fetal mouse tissues and is alternatively spliced in a tissue-specific pattern in the adult. There is evidence that APP may function as a growth factor and as a mediator of cell adhesion and in these roles could be important in morphogenesis. As a step toward determining the role of APP in development and in determining how the adult pattern of tissue-specific splicing is established, we have used reverse transcription and the polymerase chain reaction to demonstrate APP expression in mouse oocytes, preimplantation embryos, and postimplantation embryonic stages to the late embryonic period. All three splicing forms described in mouse were present at each stage, although there were changes in the ratios of the splicing forms at different stages. Screens for APP clones in embryonic cDNA libraries from the egg cylinder stage and the early somite stage were used to confirm the results of the polymerase chain reaction, and APP clone abundance was found to increase 10-fold between the two stages.
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Affiliation(s)
- S Fisher
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205
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23
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Nerve growth factor corrects developmental impairments of basal forebrain cholinergic neurons in the trisomy 16 mouse. Proc Natl Acad Sci U S A 1991; 88:1793-7. [PMID: 2000385 PMCID: PMC51111 DOI: 10.1073/pnas.88.5.1793] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The trisomy 16 (Ts16) mouse, which shares genetic and phenotypic homologies with Down syndrome, exhibits impaired development of the basal forebrain cholinergic system. Basal forebrains obtained from Ts16 and euploid littermate fetuses at 15 days of gestation were dissociated and cultured in completely defined medium, with cholinergic neurons identified by choline acetyltransferase (ChAT) immunoreactivity. The Ts16 cultures exhibited fewer ChAT-immunoreactive neurons, which were smaller and emitted shorter, smoother, and more simplified neurites than those from euploid littermates. Whereas the addition of beta-nerve growth factor (100 ng/ml) augmented the specific activity of ChAT and neuritic extension for both Ts16 and euploid cholinergic neurons, only Ts16 cultures exhibited an increase in the number and size of ChAT-immunoreactive neurons. Furthermore, Ts16 ChAT-immunoreactive neurites formed varicosities only in the presence of beta-nerve growth factor.
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24
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Fine A, Ault B, Rapoport SI. Mouse trisomy 16 neurons, a model of human trisomy 21 (Down syndrome), can be maintained by intracerebral transplantation. Neurosci Lett 1991; 122:4-8. [PMID: 1711657 DOI: 10.1016/0304-3940(91)90179-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The trisomy 16 mouse is considered to be a model of human trisomy 21 (Down syndrome) due to genetic homology between parts of human chromosome 21 and mouse chromosome 16. Additionally, and because older Down syndrome individuals develop neuropathology indistinguishable from that of Alzheimer's disease, trisomy 16 tissue may provide a model of some pathological processes occurring in Alzheimer's disease. However, trisomy 16 fetuses die in utero or shortly after birth, preventing exploitation of this model. We therefore sought to examine trisomy 16 brain tissue over an extended period of time. We report that neural transplantation to normal hosts allows the maintenance of cortical and hippocampal neurons for at least 8 months, thus providing a model in which to examine pathological processes related to Down syndrome, and perhaps to Alzheimer's disease.
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Affiliation(s)
- A Fine
- Department of Physiology and Biophysics, Dalhousie University, Halifax, N.S., Canada
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25
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Affiliation(s)
- R H Reeves
- Developmental Genetics Laboratory, Johns Hopkins University School of Medicine, Baltimore, MD 21205
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26
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Affiliation(s)
- J H Nadeau
- Jackson Laboratory, Bar Harbor, ME 04609
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27
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Reeves RH, Crowley MR, O'Hara BF, Gearhart JD. Sex, strain, and species differences affect recombination across an evolutionarily conserved segment of mouse chromosome 16. Genomics 1990; 8:141-8. [PMID: 1981993 DOI: 10.1016/0888-7543(90)90236-n] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A region of substantial genetic homology exists between human chromosome 21 (HSA21) and mouse chromosome 16 (MMU16). Analysis of 520 backcross animals has been used to establish gene order in the homologous segment. D21S16h and Mx are shown to represent the known proximal and distal limits of homology between the chromosomes, while Gap43, whose human homolog is on HSA3, is the next proximal marker on MMU16 that has been mapped in the human genome. Recombination frequencies (RFs) in four intervals defined by five loci in the HSA21-homologous region of MMU16 were analyzed in up to 895 progeny of eight different backcrosses. Two of the eight crosses were made with F1 males and six with F1 females. The average RF of 0.249 in 265 backcross progeny of F1 males was significantly higher than the 0.106 average recombination in 320 progeny of F1 females in the interval from D21S16h to Ets-2. This is in contrast to HSA21, which shows higher RFs in female meiosis in the corresponding region. Considerable variation in RF was observed between crosses involving different strains, both in absolute and in relative sizes of the intervals measured. The highest RFs occurred in a cross between the laboratory strain C57BL/6 and MOLD/Rk, an inbred strain derived from Mus musculus molossinus. RFs on this cross were nearly fivefold higher than those reported previously for an interspecific cross between C57BL/6 and Mus spretus.
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Affiliation(s)
- R H Reeves
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2196
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28
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Gardiner K, Horisberger M, Kraus J, Tantravahi U, Korenberg J, Rao V, Reddy S, Patterson D. Analysis of human chromosome 21: correlation of physical and cytogenetic maps; gene and CpG island distributions. EMBO J 1990; 9:25-34. [PMID: 2295313 PMCID: PMC551626 DOI: 10.1002/j.1460-2075.1990.tb08076.x] [Citation(s) in RCA: 121] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Human chromosome 21 has been analyzed by pulsed-field gel electrophoresis using somatic cell hybrids containing limited regions of the chromosome and greater than 60 unique sequence probes. Thirty-three independent NotI fragments have been identified, totalling 43 million bp. This must account for essentially the entire long arm, and therefore gaps remaining in the map must be small. The extent of the pulsed-field map has allowed the direct correlation of the physical map with the cytogenetic map: translocation breakpoints can be unambiguously positioned along the long arm and the distances between them measured in base pairs. Three breakpoints have been identified, providing physical confirmation of cytogenetic landmarks. Information on sequence organization has been obtained: (i) 60% of the unique sequence probes are located within 11 physical linkage groups which can be contained in only 20% of the long arm; (ii) 9/21 genes are clustered within 4%; (iii) translocation breakpoints appear to occur within CpG island regions, making their identification difficult by pulsed-field techniques. This analysis contributes to the human genome mapping effort, and provides information to guide the rapid investigation of the biology of chromosome 21.
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Affiliation(s)
- K Gardiner
- Eleanor Roosevelt Institute for Cancer Research, Denver, CO
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29
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Higgins GA. Should a unified nomenclature be adopted for the amyloid protein of Alzheimer's disease? Neurobiol Aging 1990; 11:61-2. [PMID: 2325818 DOI: 10.1016/0197-4580(90)90064-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- G A Higgins
- Department of Neurobiology and Anatomy, University of Rochester Medical Center, NY 14642
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30
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Fisher S, Oster-Granite ML. Developmental expression of amyloid precursor protein in normal and trisomy 16 mice. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1990; 265:311-8. [PMID: 1974107 DOI: 10.1007/978-1-4757-5876-4_30] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- S Fisher
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
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31
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Richards SJ, Waters JJ, Rogers DC, Martel FL, Sparkman DR, White CL, Beyreuther K, Masters CL, Dunnett SB. Hippocampal grafts derived from embryonic trisomy 16 mice exhibit amyloid (A4) and neurofibrillary pathology. PROGRESS IN BRAIN RESEARCH 1990; 82:215-23. [PMID: 2149769 DOI: 10.1016/s0079-6123(08)62607-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- S J Richards
- MRC Molecular Genetics Unit, Addenbrooke's Hospital, Cambridge, England, UK
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32
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Beyreuther K, Masters CL. Nomenclature of amyloid A4 proteins and their precursors in Alzheimer's disease and Down's syndrome. Neurobiol Aging 1990; 11:66-8. [PMID: 1970128 DOI: 10.1016/0197-4580(90)90067-a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- K Beyreuther
- Center for Molecular Biology, University of Heidelberg, FRG
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33
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Triarhou LC, Low WC, Ghetti B. Dopamine neurone grafting to the weaver mouse neostriatum. PROGRESS IN BRAIN RESEARCH 1990; 82:187-95. [PMID: 2290935 DOI: 10.1016/s0079-6123(08)62604-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- L C Triarhou
- Department of Pathology, Indiana University School of Medicine, Indianapolis 46202-5120
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34
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Kiss J, Schlumpf M, Balázs R. Selective retardation of the development of the basal forebrain cholinergic and pontine catecholaminergic nuclei in the brain of trisomy 16 mouse, an animal model of Down's syndrome. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1989; 50:251-64. [PMID: 2575464 DOI: 10.1016/0165-3806(89)90201-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Brain development, examined at embryonic day 17, was retarded in murine trisomy 16 (Ts16). Ts16 is considered to serve as a model of the human trisomy 21 (Down's syndrome) by virtue of the presence in the mouse chromosome 16 of a set of genes located in humans in the segment of chromosome 21 that is requisite to produce the phenotypic features of Down's syndrome when present in triplicate. In addition to a reduction in brain size and cortical thickness, we observed a severe reduction throughout the brain in the density of muscarinic receptors, assessed by autoradiographic detection of specifically bound tritiated N-methyl-scopolamine, and by the failure of the development of the differentiated pattern of receptor distribution in the brainstem. The effect of gene dosage was also examined on specific neuronal populations. The distribution of acetylcholine esterase (AChE)-, tyrosine hydroxylase (TH)- and 5-hydroxytryptamine (5-HT)-positive cells in the trisomic brain was similar to that observed in chromosomally balanced littermates. On the other hand, the number of AChE-positive cells was 60-70% of the estimates in littermate controls in regions containing the septum, the vertical and horizontal limbs of the diagonal band and the basal forebrain cholinergic nuclei. Similarly, the number of TH-positive cells was reduced by about 30% in the pons. In contrast, in the trisomic foetuses the number of TH-positive cells in the mesencephalon and the diencephalon was similar to that in littermate controls, while that of 5-HT-positive cells in the mesencephalic nuclei was only slightly affected, if at all. Ts16 results, therefore, in a selective retardation of some neuronal systems, and this may lead to a perturbation of brain development. Furthermore, the systems whose development was retarded selectively are those which in Down's syndrome adults exhibit pronounced deficits of cells that--in case the murine Ts16 is a valid model--may also involve developmental disorders.
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Affiliation(s)
- J Kiss
- Collaborative Centre, National Institute for Medical Research, London, U.K
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35
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Reeves RH, Crowley MR, Lorenzon N, Pavan WJ, Smeyne RJ, Goldowitz D. The mouse neurological mutant weaver maps within the region of chromosome 16 that is homologous to human chromosome 21. Genomics 1989; 5:522-6. [PMID: 2575584 DOI: 10.1016/0888-7543(89)90018-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Utilizing the backcross C57BL/6 wv/wv x (C57BL/6 wv/wv x MOLD/Rk), the mouse neurological mutation weaver (wv) was mapped less than 1 cM proximal to Ets-2 and Mx on mouse chromosome 16 (0.96 +/- 0.1% recombination). This region is known to include eight genes that are found on human chromosome 21 (HSA 21) and appears to be highly conserved between the two species. We therefore predict that the normal human homolog of wv will be located on HSA 21 and would be in dosage imbalance in individuals with Down syndrome.
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Affiliation(s)
- R H Reeves
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
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36
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Sweeney JE, Höhmann CF, Oster-Granite ML, Coyle JT. Neurogenesis of the basal forebrain in euploid and trisomy 16 mice: an animal model for developmental disorders in Down syndrome. Neuroscience 1989; 31:413-25. [PMID: 2529451 DOI: 10.1016/0306-4522(89)90384-9] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The neurogenesis and early histochemical differentiation of the basal forebrain in trisomy 16 fetal mice and their euploid littermates were examined by combining [3H]thymidine autoradiography with acetylcholinesterase histochemistry. Neurons of the basal forebrain were being born between embryonic day 11 and 15 in both chromosomally normal (euploid) and aneuploid mice. In euploid littermate controls, neurogenesis proceeded along a caudal to rostral gradient with the peak on embryonic day 11 for caudal portions and embryonic day 13 for rostral portions of the basal forebrain. In contrast, in trisomy 16 mice, rostral sections exhibited a peak of neurogenesis on embryonic day 11, 2 days earlier than in their euploid littermate controls. Hypocellularity of the basal forebrain region was noted in trisomy 16 mice; particularly dramatic was the reduction of the population of cells that expressed acetylcholinesterase. This reduction in cell number in the trisomics was not accompanied by a reduction in cell size or by a dramatic change in the distribution of residual neurons when compared to that of euploid littermate controls. Since trisomy 16 mice do not survive the perinatal period, we examined the pattern of acetylcholinesterase expression in normal C57B1/6J mice from embryonic day 16 to postnatal day 5 to determine the postnatal disposition of these neurons. Already at embryonic day 16, fibers staining for acetylcholinesterase penetrated the striatal anlage, in their course towards targets in the cerebral cortices. By postnatal day 5, the previously expansive distribution of basal forebrain neurons had become consolidated in a more ventral and rostral position by the extensive outgrowth of the striatal neurons, a pattern resembling that seen in adult animals.
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Affiliation(s)
- J E Sweeney
- Department of Environmental Health Sciences, Johns Hopkins University Medical Institutions, Baltimore, MD 21205
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37
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O'Hara BF, Bendotti C, Reeves RH, Oster-Granite ML, Coyle JT, Gearhart JD. Genetic mapping and analysis of somatostatin expression in Snell dwarf mice. Brain Res 1988; 464:283-92. [PMID: 2906811 DOI: 10.1016/0169-328x(88)90037-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Mice homozygous for the gene dwarf (dw) have elevated levels of somatostatin (SS) in extra-hypothalamic brain regions. By in situ hybridization, increased levels of SS mRNA were observed in regions shown previously to contain higher levels of the SS peptide. Thus, the rate of transcription and/or the stability of SS mRNA are affected by the dw mutation. Since both dw and the gene encoding SS, Smst, are located on mouse chromosome 16, two backcrosses segregating dw and Smst were used to determine whether dw is an allele of Smst. In one backcross, an inbred strain derived from the subspecies Mus musculus molossinus was used to provide a high degree of DNA sequence polymorphism. The gene order and map distances determined on this backcross were: (centromere) - Prm-1 - 7 - Igl-1 - 3 - Smst - 29 - dw - 15 - Sod-1 - 4 - Ets-2, demonstrating clearly that Smst and dw are distinct genes. Additional evidence against a primary role for SS excess in the pathogenesis of dw/dw mice was obtained by injecting normal newborn mice with a potent SS analog (cyclo II). In contrast to the pattern of cell loss observed in the dwarf anterior pituitary, the pituitaries of injected mice were indistinguishable from normal controls, further suggesting that the Smst locus is not the primary site of dw gene action.
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Affiliation(s)
- B F O'Hara
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205
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38
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Reeves RH, O'Hara BF, Pavan WJ, Gearhart JD, Haller O. Genetic mapping of the Mx influenza virus resistance gene within the region of mouse chromosome 16 that is homologous to human chromosome 21. J Virol 1988; 62:4372-5. [PMID: 2902234 PMCID: PMC253877 DOI: 10.1128/jvi.62.11.4372-4375.1988] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
A total of 318 progeny from four backcrosses involving different laboratory strains and subspecies of Mus musculus were analyzed to map the Mx gene to the region of mouse chromosome 16 (MMU 16) which is homologous to human chromosome 21 (HSA 21). This result suggests that Mx will be found in the region of HSA 21 which has been implicated in Down syndrome when inherited in three copies.
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Affiliation(s)
- R H Reeves
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
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39
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Bendotti C, Forloni GL, Morgan RA, O'Hara BF, Oster-Granite ML, Reeves RH, Gearhart JD, Coyle JT. Neuroanatomical localization and quantification of amyloid precursor protein mRNA by in situ hybridization in the brains of normal, aneuploid, and lesioned mice. Proc Natl Acad Sci U S A 1988; 85:3628-32. [PMID: 2897124 PMCID: PMC280267 DOI: 10.1073/pnas.85.10.3628] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Amyloid precursor protein mRNA was localized in frozen sections from normal and experimentally lesioned adult mouse brain and from normal and aneuploid fetal mouse brain by in situ hybridization with a 35S-labeled mouse cDNA probe. The highest levels of hybridization in adult brain were associated with neurons, primarily in telencephalic structures. The dense labeling associated with hippocampal pyramidal cells was reduced significantly when the cells were eliminated by injection of the neurotoxin ibotenic acid but was not affected when electrolytic lesions were placed in the medial septum. Since the gene encoding amyloid precursor protein has been localized to mouse chromosome 16, we also examined the expression of this gene in the brains of mouse embryos with trisomy 16 and trisomy 19 at 15 days of gestation. RNA gel blot analysis and in situ hybridization showed a marked increase in amyloid precursor protein mRNA in the trisomy 16 mouse head and brain when compared with euploid littermates or with trisomy 19 mice.
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Affiliation(s)
- C Bendotti
- Johns Hopkins University School of Medicine, Baltimore, MD 21205
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40
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Gearhart JD, Oster-Granite ML, Reeves RH, Coyle JT. Developmental consequences of autosomal aneuploidy in mammals. DEVELOPMENTAL GENETICS 1987; 8:249-65. [PMID: 2971493 DOI: 10.1002/dvg.1020080408] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Autosomal aneuploidy in mammals adversely affects developmental processes. In human beings, for example, trisomy 21 is the most frequent aneuploidy detected among newborns and the most common known genetic cause of mental retardation. In this review, several hypotheses are discussed that have been proposed to explain the mechanisms by which aneuploidy (especially trisomy) disrupts development. These mechanisms included specific gene dosage effects, generalized disruption of genetic homeostasis, and the influence of the parental origin of the duplicated chromosome. The availability of specific chromosomal rearrangements in mice, coupled with selective breeding schemes, permits generation of aneuploidy of specific chromosomes or chromosomal segments on controlled genetic backgrounds, thus enabling the systematic study of the causes and consequences of defined aneuploidy. Phenotypic characteristics associated with a number of specific aneuploidies in the mouse are discussed. Emphasis is placed on the effects of trisomy 16. Genetic homology between mouse chromosome 16 and human chromosome 21 has led investigators to suggest that analogous mechanisms will be responsible for the developmental abnormalities produced in these respective aneuploidies. Analysis of trisomy 16 mice from the organismal to the subcellular level has revealed a number of phenotypic characteristics (particularly neurobiologic ones) shared with human trisomy 21. The dosage effects of shared genes (or their products) may contribute to the development of these features.
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Affiliation(s)
- J D Gearhart
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
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41
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Saltarelli MD, Forloni GL, Oster-Granite ML, Gearhart JD, Coyle JT. Neurochemical characterization of embryonic brain development in trisomy 19 (Ts19) mice: implications of selective deficits observed for abnormal neural development in aneuploidy. DEVELOPMENTAL GENETICS 1987; 8:267-79. [PMID: 2901927 DOI: 10.1002/dvg.1020080409] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
In this study, we examined the neurochemical profiles of selected brain regions (cerebral hemispheres, diencephalon/brainstem) in fetal (day 14 to 18 gestation) trisomy 19 (Ts19) mice. The neurochemical characteristics we observed in Ts19 mice were quite different from those we observed previously in Ts16 mice. Choline acetyltransferase (ChAT) activity was reduced significantly in the cerebral hemispheres, but not in the brainstem/diencephalon, of the fetal Ts19 mouse brain, suggesting a selective vulnerability of telencephalic cholinergic neurons. Additionally, the activity of glutamic acid decarboxylase (GAD) was reduced significantly in both hemispheres and diencephalon/brainstem of late gestation Ts19 fetuses, suggesting a selective vulnerability of GABAergic neurons as well. While the levels of catecholaminergic and dopaminergic markers were reduced significantly at late gestational ages, the relative rate of turnover of dopamine (DA), measured by the ratio of DOPAC/DA, was elevated significantly in Ts19 mice. Neither reduction in the thickness of various cellular zones of the cerebral cortex nor reduced cell density of the cerebral cortex accounts for the alterations in neurochemical parameters observed in Ts19 mice. These results suggest that the effects of the triplication of specific genes on the respective chromosomes, rather than a generalized disruption of developmental homeostasis resulting from extra chromosomal material, may produce selective alterations in neurochemical and neuroanatomical markers observed in these two mouse trisomies.
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Affiliation(s)
- M D Saltarelli
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland
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