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Biomedical subjects

L Mobraaten

Publications and source records attributed to L Mobraaten.

6 recordsLinked to original sources

Effects of the non-pseudoautosomal region of the Y-chromosome on behavior in female offspring of two congenic strains of mice.

The learning behavior of female offspring of two strains of mice congenic for the Y-chromosome, BXSX/MpJ-Yaa and BXSB/MpJ-Yaa+, was examined. Significant differences were found in the Morris water maze and the Lashley III maze, demonstrating that the fathers' Y-chromosome can indirectly affect their daughters' behavior. Approximately half the mice had neocortical ectopias, and females from the two paternal groups reacted differently to the presence or absence of ectopias. Since females do not have a Y-chromosome, these effects must be through non-genetic mechanisms. Prenatal factors that could have played a role include possible differences in gonadal growth and the presence of different H-Y antigens. Postnatally, the sires and male siblings of the two strains may not have behaved the same toward the female offspring and/or the dams, creating differences in behavior. In summary, the behavior of female offspring of two groups of males, genetically the same except for their Y-chromosomes, was examined. Since females do not receive a Y-chromosome from their fathers, in theory their behavior should not differ. Significant differences were found, indicating that the Y-chromosome, through some indirect mechanism, can affect females of the next generation.

Animals↗

Cryopreservation and orthotopic transplantation of mouse ovaries: new approach in gamete banking.

Mouse half ovaries were cryopreserved and orthotopically transplanted into ovariectomized recipients genetically identical to ovary donors except for the coat color gene. Fertility was reestablished in 57% of the female recipients, which became pregnant in an average of 40 days after transplantation of frozen-thawed half ovaries. These experiments demonstrate that ovary cryopreservation can be a very useful option for banking mouse germplasm, or managing subfertile animal colonies, when embryo or sperm freezing cannot be used or is not cost effective.

Animals↗

Multiple defects in innate and adaptive immunologic function in NOD/LtSz-scid mice.

The scid mutation was backcrossed ten generations onto the NOD/Lt strain background, resulting in an immunodeficient stock (NOD/LtSz-scid/scid) with multiple defects in adaptive as well as nonadaptive immunologic function. NOD/LtSz-scid/scid mice lack functional lymphoid cells and show little or no serum Ig with age. Although NOD/(Lt-)+/+ mice develop T cell-mediated autoimmune, insulin-dependent diabetes mellitus, NOD/LtSz-scid/scid mice are both insulitis- and diabetes-free throughout life. However, because of a high incidence of thymic lymphomas, the mean lifespan of this congenic stock is only 8.5 mo under specific pathogen-free conditions. After i.v. injection of human CEM T-lymphoblastoid cells, splenic engraftment of these cells was fourfold greater in NOD/LtSz-scid/scid mice than in C.B17/Sz-scid/scid mice. Although C.B-17Sz-scid/scid mice exhibit robust NK cell activity, this activity is markedly reduced in both NOD/(Lt-)+/+ and NOD/LtSz-scid/scid mice. Presence of a functionally less mature macrophage population in NOD/LtSz-scid/scid vs C.B-17Sz-scid/scid mice is indicated by persistence in the former of the NOD/Lt strain-specific defect in LPS-stimulated IL-1 secretion by marrow-derived macrophages. Although C.B-17Sz-scid/scid and C57BL/6Sz-scid/scid mice have elevated serum hemolytic complement activity compared with their respective +/+ controls, both NOD/(LtSz-)+/+ and NOD/LtSz-scid/scid mice lack this activity. Age-dependent increases in serum Ig levels (> 1 micrograms/ml) were observed in only 2 of 30 NOD/LtSz-scid/scid mice vs 21 of 29 C.B-17/Sz-scid/scid animals. The multiple defects in innate and adaptive immunity unique to the NOD/LtSz-scid/scid mouse provide an excellent in vivo environment for reconstitution with human hematopoietic cells.

Agammaglobulinemia↗

Genetic and nongenetic control of the immune response of mice to a synthetic glycolipid, stearylisomaltotetraose.

Evidence for genetic control of antibody response to stearylisomaltotetraose (ST-IM4), a chemically defined synthetic glycolipid, was studied in various mouse strains. Anti-glycolipid antibodies were induced by repeated injections of ST-IM4 in complete Freund's adjuvant. C57BL and CBA/J mice were found to be good responders, while A/J, SJL/J, and AKR/J mice were poor responders. Responsiveness is independent of the H-2 genotype since AKR/J and CBA/J mice share the same H-2 locus. In addition, B10.A and B10.PL mice developed antibody levels similar to those of C57BL. The immunoglobulin heavy-chain locus (IgCH) was also found not to control antibody levels to ST-IM4 since C57BL and SJL/J mice share the same IgCH allotype. In C58/J mice, wide variation in response was observed among individual mice. Study of the response to ST-IM4 in 12 breeder pairs from different family lines of the C58/J colony also indicated that the regulation of the immune response to ST-IM4 is apparently more complex than can be explained by single gene control. C58 mice, unlike many other strains, had very low preimmune titers.

Animals↗

Cross-reactive cytotoxic responses. H-2 restricted are more specific than anti-H-2 responses.

Cross-reactive T-cell cytotoxicity is seen when cytotoxic responses are generated in mixed lymphocyte cultures either between mouse strans which differ at the major histocompatibility complex, H-2, or between H-2b mutant strains and the strain from which they were derived. This cross-reactivity can be measured with [51Cr] labeled target cells from a number of different H-2 haplotypes, and the pattern of cross-reaction indicates that the target antigens are unlikely to be any of the serologically defined public specificities. In contrast, the specificity of H-2 restricted cytotoxic responses, such as that to the male-specific antigen, H-Y, is exquisite, and male cells from strains of mice carrying H-2 haplotypes other than the responder have never been found to act as appropriate targets. The contrast between the specificity of anti-H-2 and H-2 restricted responses may argue for a greater idiotypic homogeneity of the cells makiing H-2 restricted responses, and the greater specificity of these responses may be necessary for their biological function.

Animals↗