Teratogenesis of acetazolamide in the CBA/J and SWV strains of mice. I. Teratology.

SWV mice were totally resistant to the teratogenic and embryolethal actions of acetazolamide. The time of maximal sensitivity to acetazolamide-induced ectrodactyly in the CBA/J strain was the middle of day 10; the dose response at this time was studied. Comparison of the responses of the two strains and reciprocal hybrids indicated that sensitivity is a property of the embryo and is not maternally mediated. SWV mice were also resistant to dichlorphenamide which suggests they may be resistant to many or even all teratogenic carbonic anhydrase inhibitors.     

Genetic differences in the frequency of acetazolamide-induced ectrodactyly in the mouse exhibit directional dominance of relative embryonic resistance

Eleven of the common inbred strains of the mouse were surveyed for their teratogenic response to acetazolamide that was administered three times per os at 1,000 mg/kg (9 A.M. and 4 P.M. on day 9 and 9 A.M. on day 10). The products of conception were examined for gross malformations on day 15. One strain, SJL/J, exhibited maternal toxicity to the dosage regime and was excluded from the survey. Five strains exhibited significantly increased resorption rates after treatment. All strains responded with the expected malformation of postaxial forelimb ectrodactyly with a right-sided predominance. Nine of the strains could be assigned to one of four mutually exclusive classes of frequency of ectrodactyly and the tenth strain (BALB/cByJ) showed overlap between the two intermediate classes. The data suggest major genes determine the difference in sensitivity to ectrodactyly rather than a polygenic mode of inheritance. Induced cleft lip was found in four strains and one of these strains, SWR/J, exhibited a significantly higher frequency. The strain differences in sensitivity to induced resorption, forelimb ectrodactyly, and cleft lip were genetically independent. A reciprocal cross study was conducted with five of the strains from the four classes of frequency of ectrodactyly response in order to determine gene action. A significant maternal effect on the ectrodactyly response was found only with one of the strain pairs in the ten sets of reciprocal crosses with the five strains. When there was a significant difference between two strains, the F1 embryos exhibited dominance of relative resistance to ectrodactyly. The directional dominance of relative resistance to acetazolamide-induced ectrodactyly suggests that regulatory genes control the embryonic differences in frequency of ectrodactyly response to acetazolamide. By analogy with other metric traits of development that exhibit directional dominance, the genetic variation in ectrodactyly response that has been observed so far in the mouse embryo may not be involved with the primary target of acetazolamide teratogenesis.     

The effect of administration time on malformations induced by three anticonvulsant agents in C57BL/6J mice with emphasis on forelimb ectrodactyly.

Exposure of C57BL/6J mice to three anticonvulsant derivatives, namely, dimethadione, sodium valproate, and sodium diphenylhydantoin, each induced postaxial forelimb ectrodactyly. The agents were administered at gestational days 9, 9 1/3, 9 2/3, and 10. It was determined that administration at day 9 2/3 induced the highest percentage of forelimb ectrodactyly for each of the three agents. The forelimb ectrodactyly response in the C57BL/6J strain was compared with the A/J strain (Collins et al., Teratology, 41:61-70, 1990); it was found that the C57BL/6J strain was more sensitive to dimethadione and the A/J strain was more sensitive to diphenylhydantoin and sodium valproate. The position of vertebral defects induced by sodium valproate correlated with the time of drug administration. The overall syndrome of malformations induced by the three anticonvulsant agents was relatively similar in the two mouse strains and differed between each of the anticonvulsant agents.     

Association of ectrodactyly and distal phocomelia

Ectrodactyly and phocomelia are well known limbs malformations.They can be a part of various syndromes, and are more often transmitted with dominant autosomal Inheritance with variable expression and Incomplete penetrance. Different loci have been Identified for ectrodactyly (SHFM1 at 7q21.3q22.1, SHFM2 at Xq26, SHFM3 at 10q24q25, SHFM4 at 3q27), and two genes are known (DSS1 for SHFM1, p63 for SHFM4). We report the case of a 33 year-old female affected with the association of ectrodactyly and phocomelia. It could be a "new" association, or a mild or partial expression of the syndrome Including ectrodactyly, phocomelia, deafness and sinusal arythmia.     

Detection of a new cerebral malaria susceptibility locus,using CBA mice

Human cerebral malaria (CM) during acute Plasmodium falciparum infection is a serious neurological complication that leads to coma and death. P. berghei ANKA infection of CBA mice is a useful experimental model of CM. To identify host susceptibility loci, we performed chromosomal mapping in crossbred populations of both CM-susceptible CBA and CM-resistant DBA/2 mice. One significant region for a CM-susceptible locus in CBA mice was mapped to H2 region on Chromosome 17, tentatively designated cmsc. cmsc was mapped to a different chromosomal region from that previously reported in the C57BL/6 mouse model of CM. It is possible that different loci contribute to CM in CBA and C57BL/6 mouse strains. Comparison of the function of CM susceptibility loci between CBA and C57BL/6 mice could have important implications for the study of the complex pathogenesis of CM in humans.     

Radiation-induced mutation at tandem repeat DNA Loci in the mouse germline: spectra and doubling doses

The spectra and dose response for mutations at expanded simple tandem repeat (ESTR) loci in the germline of male mice acutely exposed to low-LET X or gamma rays at pre-meiotic stages of spermatogenesis were compared in five strains of laboratory mice. Most mutation events involved the gain or loss of a relatively small number of repeat units, and the distributions of length changes were indistinguishable between the exposed and control males. Overall, a significant bias toward gains of repeats was detected, with approximately 60% of mutants showing gains. The values for ESTR mutation induction did not differ substantially between strains. The highest values of doubling dose were obtained for two genetically related strains, BALB/c and C.B17 (mean value 0.98 Gy). The estimates of doubling dose for three other strains (CBA/H, C57BL/6 x CBA/H F1 and 129SVJ x C57BL/6) were lower, with a mean value of 0.44 Gy. The dose response for ESTR mutation across all five strains was very close to that for the specific loci (Russell 7-locus test). The mechanisms of ESTR mutation induction and applications of this system for monitoring radiation-induced mutation in the mouse germline are discussed.     

Spalthand-/Spaltfu?fehlbildungen

Split-hand/foot malformation (SHFM), also known as ectrodactyly, is characterized by malformations primarily affecting the central rays of the hands and/or feet that often result in formation of a deep median cleft. Based on the study of mouse models a defect in the maintenance of the apical ectodermal ridge has been postulated as the underlying pathomechanism. Currently, six loci for SHFM have been mapped, and point mutations as well as genomic rearrangements (duplications, deletions, translocations) have been identified. However, in many cases the genetic cause still remains unknown. Using genome-wide screening methods such as array CGH, microduplications at chromosome 17p13.3 were recently shown to be associated with ectrodactyly and tibial hemimelia. This article presents an overview of the genetic principles, pathogenesis and inheritance underlying SHFM as well as a scheme for diagnostic approaches to non-syndromic SHFM.     

Properties of reticulum cell sarcomas in SJL/J mice. III. Promotion of tumor growth in irradiated mice by normal lymphoid cells.

Experiments were performed to elucidate the mechanisms by which lymphocytes obtained from an M-antigen-incompatible strain reduce the specific mixed lymphocyte culture (MLC) response of lymphoid cell populations after injection into allogeneic recipients. Mice of strain CBA were injected with spleen cells from hybrids of the H-2-compatible, M-antigen-incompatible strain C3H. Normal C3H × CBA spleen cells increased the MLC reactivity of the host's lymphocytes during the first 1–3 days, and thereafter the response against C3H was drastically reduced. Mitomycin-treated or antibody-coated C3H × CBA cells rather enhanced the MLC responsiveness. Roughly similar results were obtained by injecting untreated H-2-incompatible C3H hybrid lymphocytes. Lymph node or spleen cell populations from CBA mice, injected with C3H × CBA cells up to 2 weeks earlier, were found to depress the MLC reactivity against C3H when transferred to new CBA hosts. The results indicate that injected cells had survived for 2 weeks in the host. On the other hand, H-2-incompatible C3H hybrid cells could not be detected even at day 3 after injection into CBA mice. The results also indicate that C3H hybrid lymphocytes have to be functionally intact and able to survive in the host for a relatively long period of time to be able to reduce the specific MLC response of the host's lymphocytes.     

Distinct host-dependent pathogenic mechanisms leading to a similar clinical anemia after infection with lymphocytic choriomeningitis virus

The Docile strain of lymphocytic choriomeningitis virus (LCMV) induces anemia in a number of inbred strains of mice, including C3HeB/FeJ and CBA/Ht animals. A difference in the kinetics of anemia and in compensatory reticulocytosis suggested that impaired erythropoiesis was the major pathogenic mechanism involved in CBA/Ht mice, but not in C3HeB/FeJ mice. In both mouse strains an antierythrocyte autoantibody production that depended on the presence of functional CD4+ T lymphocytes was observed. Although depletion of T helper lymphocytes prevented anemia in C3HeB/FeJ mice, this treatment largely failed to inhibit the development of the disease in CBA/Ht animals. This observation indicated that the antierythrocyte autoimmune response induced by the infection was at least partly responsible for the anemia of C3HeB/FeJ mice, but not of CBA/Ht mice. Erythrophagocytosis was enhanced in both mouse strains after LCMV infection, but did not appear to be a major cause of anemia. These data clearly indicate that similar disease profiles induced by the same virus in two different host strains can be the result of distinctly different mechanisms.     

The effect of aging on the induction of humoral and cellular immunity and tolerance in two long-lived mouse strains.

Aging is a complex process that adversely affects most if not all components of the immune system. In this report, two long-lived mouse strains have been compared in ability to generate both antigen-specific immunity and tolerance. Although CBA/CaJ mice produced high levels of antibody following injection of aqueous preparations of aggregated human gamma-globulin (AHGG), C57BL/6 mice made only meager antibody responses to such preparations. Age dramatically affects the humoral anti-HGG response to aqueous AHGG in both strains, but the meager response of young C57BL/6 mice was at insignificant levels in aged C57BL/6 mice. Conversely, both mouse strains generated good responses following injection of HGG in complete Freund's adjuvant at both the T and B cell level as evidenced by in vitro antigen-specific T cell proliferation and anti-HGG antibody production. Aged mice of both strains showed a marked decrease in the production of serum anti-HGG antibody in comparison to young mice. Although the antigen-specific T cell proliferative response was significantly decreased in aged CBA/CaJ mice, such proliferation was not affected in aged mice of the C57BL/6 strain. Removal of CD8+ cells from lymph node T cells of either young or aged C57BL/6 mice did not increase the antigen-specific proliferative response, suggesting that loss of CD8+ suppressors during the aging process is not responsible for the high level of antigen-specific T cell proliferation in aged C57BL/6 mice. Tolerance to HGG was readily induced in both young and aged C57BL/6 and CBA/CaJ mice although aged mice demonstrate a modest resistance to tolerance induction when compared to their young counterparts. This resistance was observed in both antibody production and antigen-specific T cell proliferation.     

Effects of estrogen on the uterus of mice of different strains]

The strain differences in the response of uterus to the administration of exogenous oestrogen was studied. The uterus of mouse strain CBA appeared to be more susceptible than in strains C57B16 and C3HA, this manifested itself in a lower threshold for development of pseudoestrus and a more pronounced increase of uterine weight.     

Multigene control of Mls c

Festenstein originally described the Mls locus as a single dominant autosomal gene with four alleles which mapped in the 13th linkage group of chromosome 1. We subsequently presented evidence which indicated that the mixed leukocyte reaction stimulatory products of DBA/2 and CBA/J were controlled by two independently segregating Mls loci. Recently, Mls ^d of CBA/J was shown to be composed of Mls ^a of AKR and Mls ^c of C3H. In the present report, classic segregation data is presented which indicates that Mls ^c of C3H is controlled by three independently segregating loci. As defined by stimulatory patterns of numerous cell lines, we postulate the following: either one of the loci is shared with BALB.K, CE, C58, and partially with MA/MyJ, one is shared with CBA/H and CBA/J, and one is shared with BALB.K, CBA/J, and partially with CE; or the groups of shared determinants are controlled by different alleles of unique loci (or locus). In any event, Mls ^c appears to be composed of at least three independently segregating loci; the number of alleles/locus is being investigated. In addition, C3H was stimulated by BALB.K (both were recently postulated to be Mls ^c ); this epitope was shared with CBA/J, CBA/H, AKR/Cum, Ma/MyJ, and C58/J.     

The role of cellular proliferation in the induction of experimental autoimmune thyroiditis (EAT) in mice

Experimental autoimmune thyroiditis (EAT) can be induced in susceptible strains of mice by injection of mouse thyroglobulin (MTg) and adjuvant. Lymphocytes from immunized mice develop a proliferative response to MTg which generally correlates with the development of EAT. We utilize a cell transfer system wherein spleen cells from CBA/J mice primed with MTg and lipopolysaccharide (LPS) in vivo are activated by culture with MTg in vitro to transfer EAT to naive recipients. In vivo priming of CBA/J mice is required to develop an antigen specific proliferative response to MTg. This response is optimal between 48 and 90 hr of culture at an MTg concentration of 125-250 micrograms/ml. The correlation between proliferation and transfer of EAT is not absolute as primed Balb/c X CBA/J F1 and AKR lymphocytes do not proliferate detectably in response to MTg but can be activated to transfer EAT; primed Balb/c lymphocytes neither proliferate nor transfer EAT. Proliferation per se is not sufficient to activate cells to transfer EAT as culture with nonspecific mitogens is not effective in activating primed CBA/J spleen cells to transfer EAT. However, lymphoblasts generated during in vitro culture of primed CBA/J spleen cells with MTg are responsible for transfer of EAT; small lymphocytes are ineffective. We conclude that antigen specific proliferation in response to MTg is essential in activating lymphocytes in vitro to transfer EAT.     

Number of chromocentres in the nuclei of mouse Sertoli cells in relation to the strain and age of males from puberty to senescence

Nuclei of mouse Sertoli cells were examined on air-dried toluidine blue-stained preparations to analyse factors influencing the aggregation of heterochromatin into chromocentres. For the CBA strain males tested at 1.3, 2, 3, 6, 9 and 12 months of age, mean numbers of heterochromatin bodies were 4.8, 2.4, 2.1, 1.8, 1.6 and 1. 4, respectively; two chromocentres predominated from 2 to 9 months of age. In the KE strain, heterochromatin aggregation was significantly accelerated; nuclei containing only one chromocentre were predominant from 6 months. The number of chromocentres did not change with the stages of the seminiferous cycle, and after 1 month of cryptorchid condition. Cryptorchidism resulted in disruption of spermatogenesis and Sertoli cell dysfunction, as demonstrated by the lack of immunohistochemically detectable androgen receptors. The difference in the number of chromocentres between KE and CBA Sertoli cells persisted after 3 days of in vitro culture, but unidentified cells with numerous chromatin bodies were also observed. Testing recombinant inbred strains indicates that at least two genes are involved in the difference in the number of chromocentres between progenitor KE and CBA strains; however, no correlations were found with 15 marker loci or with parameters linked to reproduction. Of the eight strains tested, AKR and C3H showed a 'CBA-like' chromocentre pattern; C57BL, B10.BR, B10.BR-Y(del) and KP were 'KE-like'; and BALB/c and DBA/2 were intermediate. The results showed that centromere aggregation in the Sertoli cell progresses throughout the life of a male in a strain specific manner; however, its functional significance remains unknown.     

Susceptibility loci to coronary arteritis in animal model of Kawasaki disease induced with Candida albicans -derived substances

We have established an animal model of coronary arteritis which is histopathologically similar to that observed in cases of Kawasaki disease (KD), is a well-known childhood vasculitis syndrome. Coronary arteritis in this mouse model has been induced by intraperitoneal injection of Candida albicans -derived substances (CADS). Arteritis varied by mouse strain with the highest incidence by 71.1% (27/38) found in C3H/HeN mice, but absent in CBA/JN mice (0%, 0/27), suggesting association of genomic background to develop the disease. The present study aims to elucidate the susceptibility loci associated with coronary arteritis by using this animal model. The association of the onset of arteritis with polymorphic microsatellite markers between the two strains was examined using one hundred and fifteen of N1 backcross progeny [(CBAxC3H)F1xC3H]. Based on our analysis, arteritis-susceptibility loci with suggestive linkage were mapped on D1Mit171 and D1Mit245(map position 20.2 cM) on chromosome 1 (P=0.0019). These loci include several kinds of inflammatory cytokine receptors, such as interleukin 1 receptor and tumor necrosis factor receptor. We also found the cytokine response against CADS, levels of inflammatory cytokines interleukin-1 beta, tumor necrosis factor-alpha, and interleukin-6 in sera increased within 24 hr after CADS injection. Our results may indicate based on genomics that ligand-receptor interaction between these inflammatory cytokines and the receptors of these cytokines may affect the onset of arteritis.     

Synergistic effects of the xid gene in X chromosome congenic mice. I. Inability of C3.CBA/N mice to respond to thymus-dependent antigens in adoptive transfer assays

The xid gene, which causes a B lymphocyte immune defect in CBA/N mice, has been bred onto the C3H/HeN background. The resulting X chromosome congenic mice (C3.CBA/N) exhibit immunologic defects that are much more profound than the defect exhibited by CBA/N mice; thus, the B cells from C3.CBA/N mice not only fail to respond to thymus-independent (TI) type 2 antigens such as TNP-Ficoll, but they fail to respond in vitro to TI-type 1 antigens such as TNP-Brucella abortus (BA) and B cell mitogens such as LPS and Nocardia water-soluble mitogen. In this paper we show that the synergistic defect seen in C3.CBA/N B cells is also elicited in adoptive transfer assays to thymus-dependent (TD) antigens such as TNP-KLH and PC-KLH, antigens to which both parental strains respond. Thus, the secondary adoptive transfer response of C3.CBA/N spleen cells is generally less than 5% of the immune response produced by CBA/N or C3H/HeN spleen cells. This synergistic defect is restricted to the C3.CBA/N B cells, since C3.CBA/N T cells can provide help to CBA/N B cells that is equivalent to the help obtained with CBA/N T cells. The low responsiveness of C3.CBA/N spleen cells to TD antigens, which is elicited in adoptive transfer assays, is not seen when the intact animal is immunized with antigen in CFA; this, intact C3.CBA/N mice produce anti-PC-KLH and anti-TNP-KLH responses only slightly lower than the responses of CBA/N mice to these same antigens. In contrast, when these mice are immunized with phenol-extracted LPS, a TI-type 1 antigen, their antibody responses are severely depressed. These data suggest that under conditions in which T cell help may be limiting or in which the intact physiology of the T and B cells has been disrupted, C3.CBA/N B cells demonstrate profound immunologic impairment; however, when adequate T cell help is available and the splenic architecture is not disrupted, their immune responses appear to progress in a normal fashion.     

Selection for the Predisposition to Catalepsy Enhances Depressive-like Traits in Mice

Immobility reaction or catalepsy is a natural passive defensive (cryptic) behavioral response to the appearance of a predator. Selection for high predisposition to catalepsy has been performed in a population of (CBA × (CBA × AKR)) backcrosses of the crossing between mouse lines prone and resistant to catalepsy (CBA and AKR, respectively). A rapid increase in the number of animals with catalepsy has been observed: from 23% in backcrosses to 71% in the S₃ generation. Selection for catalepsy does not affect mouse anxiety in the open field and plus-maze tests. However, S₈ and S₉ mice are characterized by a decreased motor activity in the open-field test and an increased immobility in the forced swim and tail suspension tests, which is interpreted as an increase in “ depressiveness.” The results indicate that genetically determined catalepsy is related to depressive-like characteristics of defensive behavior.     

Enhanced egg-induced immunopathology correlates with high IFN-gamma in murine schistosomiasis: identification of two epistatic genetic intervals

The genetic basis of dissimilar immunopathology development among mouse strains infected with Schistosoma mansoni is not known. We performed a multipoint parametric linkage analysis on a cohort of F(2) mice, offspring of brother-sister mating between (high pathology CBA x low pathology BL/6)F(1) mice, to examine whether the observed differences in the type of immune response or the extent of hepatic immunopathology are linked to any particular genomic intervals. The F(2) mice exhibited cytokine responses and immunopathologies that revealed a statistically significant correlation between prominent egg Ag-stimulated IFN-gamma production by mesenteric lymph node cells and hepatic egg granuloma size. Increased IFN-gamma production showed suggestive linkage to a dominant CBA locus on chromosome 1 and a recessive CBA locus on chromosome 5; significantly, there was an epistatic interaction between the two IFN-gamma loci. An additional locus with suggestive linkage to granuloma formation and a CBA-recessive mode of inheritance was mapped to centromeric chromosome 13. Our analysis identified the first three genetic regions that appear to influence the immunopathology in murine schistosomiasis; however, further congenic dissection studies will furnish a more precise understanding of the genetic control of this disease.     

Heterogeneity of the effectors of natural killer activity in CBA mice

The natural cytotoxicity of Percoll fractions of CBA mice splenocytes was tested against cells of human erythroblastosis suspension culture K-562 and murine C3HA hepatoma solid culture MGXXIIa. The 1.076 g/ml dense fraction was shown to have the highest activity in 3H-uridine cytotoxic test against the cell targets. Immunosera prepared by the Golub method against CBA mouse brains and exhausted supplementary by syngeneic thymocytes decreased the natural cytotoxicity of CBA mouse splenocytes against MGXXIIa tumor cells and, on the contrary, increased it against K-562 tumor cells.