scholarly journals Genetic epilepsy model derived from common inbred mouse strains.

Genetics ◽  
1994 ◽  
Vol 138 (2) ◽  
pp. 481-489
Author(s):  
W N Frankel ◽  
B A Taylor ◽  
J L Noebels ◽  
C M Lutz

Abstract The recombinant inbred mouse strain, SWXL-4, exhibits tonic-clonic and generalized seizures similar to the commonest epilepsies in humans. In SWXL-4 animals, seizures are observed following routine handling at about 80 days of age and may be induced as early as 55 days by rhythmic gentle tossing. Seizures are accompanied by rapid, bilateral high frequency spike cortical discharges and followed by a quiescent post-ictal phase. Immunohistochemistry of the immediate early gene products c-Fos and c-Jun revealed abnormal activation within cortical and limbic structures. The seizure phenotype of SWXL-4 can be explained and replicated fully by the inheritance of susceptibility alleles from its progenitor strains, SWR/J and C57L/J. Outcrosses of SWXL-4 with most other common inbred strains result in F1 hybrids that have seizure at least as frequently as SWXL-4 itself. Quantitative trait locus mapping reveals a seizure frequency determinant, Szf1, near the pink-eyed dilution locus on chromosome 7, accounting for up to 32% of the genetic variance in an F2 intercross between SWXL-4 and the linkage testing strain ABP/Le. These studies demonstrate that common strains of mice such as SWR and C57L contain latent epilepsy susceptibility alleles. Although the inheritance of susceptibility may be complex, these results imply that a number of potentially important and practical, noninvasive models for this disorder can be constructed and studied in crosses between common mouse strains.

Genetics ◽  
1981 ◽  
Vol 99 (1) ◽  
pp. 109-116
Author(s):  
Natalie Tulchin ◽  
Benjamin A Taylor

ABSTRACT Electrophoretically variant forms of γ-glutamyl cyclotransferase have been identified in red cells of inbred mouse strains. Each inbred strain exhibited a major band of activity and a minor band that migrated more anodally. The polymorphism affects the migration of both the major and minor bands in a similar way. F1 hybrids between strains with fast forms (A/J) and strains with the slow forms (C57BL/6J) exhibited a four-banded pattern consistent with co-dominant inheritance. The patterns observed in backcross and F2 mice were consistent with the segregation of a pair of autosomal co-dominant alleles. Recombinant inbred strains and a congenic strain were used to show that the locus controlling γ-glutamyl cyclotransferase (Ggc) is linked to Lyt-2, a lymphocyte alloantigen locus on chromosome 6, with an estimated map distance of 5.0 ± 2.5 centimorgans.


Genetics ◽  
2002 ◽  
Vol 162 (1) ◽  
pp. 297-306 ◽  
Author(s):  
Kara E Koehler ◽  
Jonathan P Cherry ◽  
Audrey Lynn ◽  
Patricia A Hunt ◽  
Terry J Hassold

AbstractGenetic background effects on the frequency of meiotic recombination have long been suspected in mice but never demonstrated in a systematic manner, especially in inbred strains. We used a recently described immunostaining technique to assess meiotic exchange patterns in male mice. We found that among four different inbred strains—CAST/Ei, A/J, C57BL/6, and SPRET/Ei—the mean number of meiotic exchanges per cell and, thus, the recombination rates in these genetic backgrounds were significantly different. These frequencies ranged from a low of 21.5 exchanges in CAST/Ei to a high of 24.9 in SPRET/Ei. We also found that, as expected, these crossover events were nonrandomly distributed and displayed positive interference. However, we found no evidence for significant differences in the patterns of crossover positioning between strains with different exchange frequencies. From our observations of >10,000 autosomal synaptonemal complexes, we conclude that achiasmate bivalents arise in the male mouse at a frequency of 0.1%. Thus, special mechanisms that segregate achiasmate chromosomes are unlikely to be an important component of mammalian male meiosis.


Genetics ◽  
1981 ◽  
Vol 99 (2) ◽  
pp. 285-307
Author(s):  
R D McCall ◽  
D Frierson

ABSTRACT Most mammals tested, when exposed to increasing pressure in helium/oxygen atmospheres, exhibit progressive motor disturbances culminating in two, usually successive, well-differentiated convulsive seizures. The seizures are highly reproducible components of the constellation of events that collectively constitute the High Pressure Neurologic Syndrome (HPNS). In the present study, we present evidence that the mean difference in seizure threshold pressures of the first seizure to occur (HPNS Type I) between inbred mouse strains DBA/2J and C57BL/6J is predominantly determined (> 60%) by the expression of a major locus—possibly linked to the H-2 locus on chromosome 17—and a minor locus, probably unlinked. This outcome is derived from applications of the maximum likelihood modeling procedure of Elston and Stewart (1973) and Stewart and Elston (1973) to eleven models of genetic determinacy and tests (including breeding tests) of "preferred" models so derived using BXD recombinant inbred strains that show the following: The major locus exhibits conditional dominance characteristics depending upon compression rate and minor locus genotype. At a constant mean compression rate of 100 atm hr-1, the major locus manifests strong, though incomplete, dominance apparently independent of minor locus genotype. Its expression is, however, highly sensitive to compression rate, losing its dominance altogether at a linear rate of 1,000 atm hr-1. The major locus interacts with the weakly dominant and relatively compression-rate-insensitive minor locus to retain dominance at fast compression only when the dominant alleles of both loci are present. A principal finding of this study is that employing two compression rates permits fuller genetic characterization of murine high-pressure seizure susceptibility differences than could be achieved by use of a single compression rate.


Genetics ◽  
1982 ◽  
Vol 100 (1) ◽  
pp. 79-87
Author(s):  
Daniel W Nebert ◽  
Nancy M Jensen ◽  
Hisashi Shinozuka ◽  
Heinz W Kunz ◽  
Thomas J Gill

ABSTRACT Forty-four inbred and four randombred rat strains and 20 inbred mouse strains were examined for their Ah phenotype by determining the induction of liver microsomal aryl hydrocarbon (benzo[a]pyrene) hydroxylase activity (EC 1.14.14.1) by intraperitoneal treatment with either β-naphthoflavone or 3-methylcholanthrene. All 48 rat strains were found to be Ah-responsive. The maximally induced hydroxylase specific activities of the ALB/Pit, MNR/Pit, MR/Pit, SHR/Pit, and Sprague-Dawley strains were of the same order of magnitude as the basal hydroxylase specific activities of the ACI/Pit, F344/Pit, OKA/Pit, and MNR/N strains. Six of the 20 mouse strains were Ah-nonresponsive (i.e. lacking the normal induction response and presumably lacking detectable amounts of the Ah receptor). The basal hydroxylase specific activities of the BDL/N, NFS/N, STAR/N, and ST/JN mouse strains were more than twice as high as the maximally induced hydroxylase specific activity of the CBA/HT strain.——To date, 24 Ah-nonresponsive mouse strains have been identified, out of a total of 68 known to have been characterized. The reasons for not finding a single Ah-nonresponsive inbred rat strain—as compared with about one Ah-nonresponsive inbred mouse strain found for every three examined—remain unknown.


1990 ◽  
Vol 172 (4) ◽  
pp. 1177-1183 ◽  
Author(s):  
R Patarca ◽  
F Y Wei ◽  
P Singh ◽  
M I Morasso ◽  
H Cantor

The development of autoimmune disease in the MRL/MpJ-lpr inbred mouse strain depends upon the maturation of a subset of T lymphocytes that may cause sustained activation of immunological effector cells such as B cells and macrophages. We tested the hypothesis that abnormal effector cell activation reflects constitutive overexpression of a T cell cytokine. We found that a newly defined T cell cytokine, Eta-1, is expressed at very high levels in T cells from MRL/l mice but not normal mouse strains and in a CD4-8- 45R+ T cell clone. The Eta-1 gene encodes a secreted protein that binds specifically to macrophages, possibly via a cell adhesion receptor, resulting in alterations in the mobility and activation state of this cell type (Patarca, R., G. J. Freeman, R. P. Singh, et al. 1989. J. Exp. Med. 170:145; Singh, R. P., R. Patarca, J. Schwartz, P. Singh, and H. Cantor. 1990. J. Exp. Med. 171:1931). In addition, recent studies have indicated that Eta-1 can enhance secretion of IgM and IgG by mixtures of macrophages and B cells (Patarca, R., M. A. Lampe, M. V. Iregai, and H. Cantor, manuscript in preparation). Dysregulation of Eta-1 expression begins at the onset of autoimmune disease and continues throughout the course of this disorder. Maximal levels of Eta-1 expression and the development of severe autoimmune disease reflect the combined contribution of the lpr gene and MRL background genes.


Genetics ◽  
1996 ◽  
Vol 142 (4) ◽  
pp. 1299-1304
Author(s):  
F Pardo-Manuel de Villena ◽  
C Slamka ◽  
M Fonseca ◽  
A K Naumova ◽  
J Paquette ◽  
...  

Abstract We determined the genotypes of >200 offspring that are survivors of matings between female reciprocal F1 hybrids (between the DDK and C57BL/6J inbred mouse strains) and C57BL/6J males at markers linked to the Ovum mutant (Om) locus on chromosome 11. In contrast to the expectations of our previous genetic model to explain the “DDK syndrome,” the genotypes of these offspring do not reflect preferential survival of individuals that receive C57BL/6J alleles from the F1 females in the region of chromosome 11 to which the Om locus has been mapped. In fact, we observe significant transmission-ratio distortion in favor of DDK alleles in this region. These results are also in contrast to the expectations of Wakasugi's genetic model for the inheritance of Om, in which he proposed equal transmission of DDK and non-DDK alleles from F1 females. We propose that the results of these experiments may be explained by reduced expression of the maternal DDK Om allele or expression of the maternal DDK Om allele in only a portion of the ova of F1 females


2018 ◽  
Author(s):  
Daniel Oreperk ◽  
Sarah A Schoenrock ◽  
Rachel McMullan ◽  
Robin Ervin ◽  
Joseph Farrington ◽  
...  

ABSTRACTParent-of-origin effects (POEs) in mammals typically arise from maternal effects or from imprinting. Mutations in imprinted genes have been associated with psychiatric disorders, as well as with changes in a handful of animal behaviors. Nonetheless, POEs on complex traits such as behavior remain largely uncharacterized. Furthermore, although perinatal environmental exposures, such as nutrient deficiency, are known to modify both behavior and epigenetic effects generally, the architecture of environment-by-POE is almost completely unexplored. To study POE and environment-by-POE, we employ a relatively neglected but maximally powerful POE-detection system: a reciprocal F1 hybrid population. We exposed female NOD/ShiLtJxC57Bl/6J and C57Bl/6JxNOD/ShiLtJ mice, in utero, to one of four different diets, then after weaning recorded their whole-brain gene expression, as well as a set of behaviors that model psychiatric disease. Microarray expression data revealed an imprinting-enriched set of over a dozen genes subject to POE; the POE on the most significantly affected gene, Carmil1 (a.k.a. Lrrc16a), was validated using qPCR in the same and in a new set of mice. Several behaviors, especially locomotor behaviors, also showed POE. Interestingly, Bayesian mediation analysis suggests Carmil1 expression suppresses behavioral POE, and Airn suppresses POE on Carmil1 expression. A significant diet-by-POE was observed on one behavior, one imprinted gene, and over a dozen non-imprinted genes. Beyond our particular results, our study demonstrates a reciprocal F1 hybrid framework for studying POE and environment-by-POE on behavior.


2010 ◽  
Vol 42A (2) ◽  
pp. 103-113 ◽  
Author(s):  
Matthew S. Barnabei ◽  
Nathan J. Palpant ◽  
Joseph M. Metzger

Inbred mouse strains play a critical role in biomedical research. Genetic homogeneity within inbred strains and their general amenability to genetic manipulation have made them an ideal resource for dissecting the physiological function(s) of individual genes. However, the inbreeding that makes inbred mice so useful also results in genetic divergence between them. This genetic divergence is often unaccounted for but may be a confounding factor when comparing studies that have utilized distinct inbred strains. Here, we compared the cardiac function of C57BL/6J mice to seven other commonly used inbred mouse strains: FVB/NJ, DBA/2J, C3H/HeJ, BALB/cJ, 129X1/SvJ, C57BL/10SnJ, and 129S1/SvImJ. The assays used to compare cardiac function were the ex vivo isolated Langendorff heart preparation and in vivo real-time hemodynamic analysis using conductance micromanometry. We report significant strain-dependent differences in cardiac function between C57BL/6J and other commonly used inbred strains. C57BL/6J maintained better cardiac function than most inbred strains after ex vivo ischemia, particularly compared with 129S1/SvImJ, 129X1/SvJ, and C57BL/10SnJ strains. However, during in vivo acute hypoxia 129X1/SvJ and 129S1/SvImJ maintained relatively normal cardiac function, whereas C57BL/6J animals showed dramatic cardiac decompensation. Additionally, C3H/HeJ showed rapid and marked cardiac decompensation in response to esmolol infusion compared with effects of other strains. These findings demonstrate the complex effects of genetic divergence between inbred strains on cardiac function. These results may help inform analysis of gene ablation or transgenic studies and further demonstrate specific quantitative traits that could be useful in discovery of genetic modifiers relevant to cardiac health and disease.


2004 ◽  
Vol 72 (8) ◽  
pp. 4439-4447 ◽  
Author(s):  
Mahtab Moayeri ◽  
Nathaniel W. Martinez ◽  
Jason Wiggins ◽  
Howard A. Young ◽  
Stephen H. Leppla

ABSTRACT Bacillus anthracis lethal toxin (LT) produces symptoms of anthrax in mice and induces rapid lysis of macrophages (Mφ) derived from certain inbred strains. We used nine inbred strains and two inducible nitric oxide synthase (iNOS) knockout C57BL/6J strains polymorphic for the LT Mφ sensitivity Kif1C locus to analyze the role of Mφ sensitivity (to lysis) in LT-mediated cytokine responses and lethality. LT-mediated induction of cytokines KC, MCP-1/JE, MIP-2, eotaxin, and interleukin-1β occurred only in mice having LT-sensitive Mφ. However, while iNOS knockout C57BL/6J mice having LT-sensitive Mφ were much more susceptible to LT than the knockout mice with LT-resistant Mφ, a comparison of susceptibilities to LT in the larger set of inbred mouse strains showed a lack of correlation between Mφ sensitivity and animal susceptibility to toxin. For example, C3H/HeJ mice, harboring LT-sensitive Mφ and having the associated LT-mediated cytokine response, were more resistant than mice with LT-resistant Mφ and no cytokine burst. Toll-like receptor 4 (Tlr4)-deficient, lipopolysaccharide-nonresponsive mice were not more resistant to LT. We also found that CAST/Ei mice are uniquely sensitive to LT and may provide an economical bioassay for toxin-directed therapeutics. The data indicate that while the cytokine response to LT in mice requires Mφ lysis and while Mφ sensitivity in the C57BL/6J background is sufficient for BALB/cJ-like mortality of that strain, the contribution of Mφ sensitivity and cytokine response to animal susceptibility to LT differs among other inbred strains. Thus, LT-mediated lethality in mice is influenced by genetic factors in addition to those controlling Mφ lysis and cytokine response and is independent of Tlr4 function.


Development ◽  
1991 ◽  
Vol 112 (1) ◽  
pp. 99-105 ◽  
Author(s):  
J.J. Brown ◽  
D.G. Whittingham

Embryos of certain inbred mouse strains, and their F1 hybrids, are able to develop from the 1-cell to blastocyst stage in simple chemically defined media containing lactate (L), pyruvate (P) and glucose (G). The individual roles of these substrates in supporting complete preimplantation development in vitro was examined with 1-cell F2 embryos from B6CBF1 hybrid mice. Embryos collected between 26 and 27 h post hCG were cultured in medium containing L, P, LP or LPG. After 50 h in culture, the proportions developing to the morula stage were 1%, 83%, 94% and 100%, respectively. In combination, lactate and pyruvate appeared to act synergistically and both the rate and level of development to the morula stage were unaffected by the absence of glucose. After a further 46 h in culture, only the embryos grown in the presence of glucose developed into blastocysts. In LP medium, embryos arrested at the compacted morula stage late on day 3 of development. As culture continued in the absence of glucose, embryos decompacted (approximately 82 h post hCG) and subsequently degenerated. Exposure to medium containing glucose for the first, second or third 24 h period in culture was sufficient to support the morula-to-blastocyst transition. Glucose still supported this transition when embryos were transferred to LPG medium 3 h after the completion of compaction (76 h post hCG), but was ineffective 6 h later (82 h post hCG) once decompaction had commenced. We conclude that lactate and pyruvate together are able to support normal development of 1-cell F2 embryos to the morula stage in vitro, but that glucose is an essential component of the culture medium for development to the blastocyst stage.


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