Limited variation in the major urinary proteins of laboratory mice

Individual variation in a specialised set of scent communication proteins, the major urinary proteins (MUPs), provides a genetic identity signature that underlies individual and kin recognition, and the assessment of heterozygosity in wild house mice. Here we examine the extent to which MUP variation is retained among 30 classical strains of laboratory mice from three main lineages (Castle, C57, Swiss). Normal wild-type variation in urinary MUP pattern appears to have been lost at an early stage in the derivation of the classical laboratory strains. All strains from the Castle and Swiss lineages shared the same “individual” MUP pattern, consistent with common ancestry from very few founders, while those from the C57 lineage shared a different pattern. Notably, individual variation in MUP pattern was no greater within the Swiss outbred ICR (CD-1) strain than typical for inbred strains. Total urinary protein concentration varied considerably between even closely related substrains, together with minor variation in the relative amount of each MUP isoform expressed, although the functional significance of such quantitative variation in MUP expression has yet to be established. Expression was 2-8 fold higher among males, while a MUP expressed by most male but not female wild mice was expressed by C57 males but variably among Castle and Swiss males and occasionally by females in some strains. The lack of normal variation in MUP patterns within and between strains has important implications for the use of laboratory mice in behavioural or neurophysiological research investigating social recognition or mate choice.     

The advertisement role of major urinary proteins in mice

The variation of expression of major urinary proteins was studied in laboratory mice to further the understanding of the role of these proteins in social and reproductive contexts. Mouse major urinary proteins (MUPs) are known to carry volatile substances and protect them during their passage from the liver, through the kidneys into the urine. However, most studies on the role of MUPs were carried out on males. Using densitometry analysis of total MUP concentration in the urine, our present study clearly demonstrates that (i) individuals of both sex up-regulate MUPs during social contact, and that (ii) females use these proteins to advertise their reproductive state by varying the concentration of MUPs during the oestrous cycle. As the concentration of MUPs was normalized by the concentration of creatinine -- a marker of glomerular filtration -- the corrected concentration of MUPs represents instantaneous expression on the level of proteins. Cross-correlation analysis between oestrus quantification and MUP expression revealed that the oestrous curve is delayed by 1 day behind the MUP curve so that the expression of MUPs is up-regulated immediately at the beginning of oestrus. To conclude, the regulation of pheromone-carrying MUPs is directly linked to reproduction and, thus, enables female honest signalling.     

Inertia of endocrine systems due to hormone binding to circulatory proteins

It is often presumed that the main role of hormone binding to albumins and binding proteins (BPs) is to reduce oscillating levels of free hormone molecules and to transport steroid hormones. This paper is an attempt to define possible consequences of hormone molecules binding to carrier proteins in circulation.Binding to albumins and BPs prevents exact and quick control of hormone actions. Hormones without significant protein binding govern vital and fast acting regulatory mechanisms (blood glucose or calcium) in which any added inertia might be dangerous. In the presented model, the added inertia for a partially bound hormone (H) is defined as: H(bound)/H(free). Values, calculated from the reported data, range from 0.4 for GH to more than 2000 for T(4). In comparison to albumins, high-affinity BPs make more stable reserve that would cover periods of low or no hormone secretion. At the same time, hormone molecules are taken away from the blood level control and thus might be considered sequestrated.For hormones without protein binding, the well-perfused areas of the body, or the areas with increased capillary permeability, would be more exposed, making an uneven distribution among target tissues. For the hormone that binds blood proteins, places of secretion and tissue perfusion become unimportant, since the hormone is being liberated anywhere in the circulation (i.e., for strongly bound IGFs, IGF binding proteins do not just stabilize proinsulin actions of IGF-1, but also make all parts of body to be under the same exposure to liberated IGFs, an important feature to promote a symmetrical bone growth).Estrogens are known to stimulate liver secretion of different BPs. A possible explanation is that in the follicular phase there is a small initial mass of granulosa cells, and it takes time to saturate free estrogen carriers, before the normal free hormone level can be reached and FSH secretion inhibited. Less inert peptide inhibin might suppress FSH before free estrogens reach the required level. Without inhibin suppression, an increased FSH level with an increased number of growing follicles can be expected. Estrogens increased production of BPs augments inertia of the estrogen loop and possibly modulates the FSH/estrogen negative feedback.     

Infanticide: accounting for genetic variation in mice

Infanticide, the killing of young, is one of a number of sexually-dimorphic traits in mice that is dependent upon androgen stimulation during perinatal life and during adulthood. Genotype also influences infanticide in that males of some strains of mice (C57BL/6J) exhibit high levels of this behavior while males of other strains (DBA/2J) seldom kill young. The experiments conducted here show that strain differences in pup killing behavior exhibited by males are not related to postweaning social factors nor are they due to differences in perinatal, pubertal, or adult levels of circulating hormones. These results, in combination with those previously reported, suggest that strain differences in the tendency of mice to kill young may instead depend upon the interaction of genotypic features such as prenatal hormone titers and/or sensitivity to these hormones, as well as on extra organismic factors such as intrauterine position. A model for understanding the manner in which genes and hormones may interact to influence infanticide and other hormone dependent sexually-dimorphic behaviors in mice is presented.     

Studies of immunological function in mice with defective androgen action. Distinction between alterations in immune function due to hormonal insensitivity and alterations due to other genetic factors.

The presence of androgen receptors in thymocytes and the well-described effects of exogenous androgens on thymus size suggest a role for androgenic hormones in thymocyte growth and maturation. Testicular feminization (Tfm/Y) mice which bear a heritable defect in the androgen receptor protein were studied to investigate how androgens might influence immune phenotype and function. These mice were compared to two types of controls; their Tabby/Y normal male littermates and male mice of the C57 Bl/6 strain from which the Tabby and Tfm mice were derived. Thymuses and spleens from Tfm/Y mice were larger than both types of controls. Phenotypic differences in thymocyte and splenocyte subpopulations identified by the T-cell markers CD3, CD4 and CD8 suggested that T-cell maturation was altered in the androgen-resistant animal. However, both Ta/Y and Tfm/Y were found to be high producers of interleukin-4 (IL-4) by both spleen and thymus cells, while cells from the C57 mice produced predominantly IL-2. These findings suggest that some immunological features of the Tfm/Y mouse may be related to its defect in androgen action, but that high levels of IL-4 production are probably related to other genetic changes in the C57 background.     

Effect of genetic variation on induced neutrophilia in mice.

Mice from a variety of strains were injected with a sterile irritant (Brewer's thioglycolate) and killed bacteria (Staphylococcus aureus, Staphylococcus epidermidis, or Escherichia coli) to determine their effect on accumulation of neutrophils in the peritoneal cavity. Peak accumulation occurred around 15 h postinjection and showed significant strain-related variation. C57BL/10 mice were identified as having a high-responder phenotype and BALB/c mice a low-responder phenotype. Inheritance of the high-responder phenotype followed simple Mendelian genetics: (BALB/c x C57BL/10)F1 mice were found to be more responsive than either parental phenotype. Major histocompatibility complex H-2d haplotype was found to convey an augmented neutrophil response in conjunction with B10 background high-responder genes (B10.D2/n) but the H-2d haplotype per se was not the only factor in determining high responsiveness. Gram-positive and gram-negative bacteria appeared to activate different immune mechanisms. Both gram-negative bacteria and lipopolysaccharides (LPS) induced a response similar to, but less potent than, that induced by Brewer's thioglycollate. Neutralization of the LPS content of Brewer's thioglycolate abrogated the response.     

Abnormal laboratory data due to interaction between immunoglobulins and other serum proteins

Two cases with abnormal laboratory data due to interaction between immunoglobulins and other serum proteins are described. Case 1 was a patient with lactate dehydrogenase (LD) -IgG3 complex whose serum LD value was moderately elevated. Case 2 were nondiabetic patients with IgA type M-proteinemia who had significantly increased serum fructosamine (FRA). The IgG3 in Case 1 was found to be conjugated to LD by immunoprecipitation assay. The LD-IgG3 complex was easily dissociated by affinity chromatography on 5'-AMP or Cibacron Blue F3G-A. The relative molecular weights of the patient's gamma3 chains and light chains were 67,000 and 28,000, respectively, by Western blotting, which corresponded to the expected values. However, the patient's IgG3 did not react to the anti-kappa and anti-lambda light chain antibodies in Immunofixation electrophoresis. Serum FRA concentrations were higher in patients (Case 2) with IgA type M-proteinemia or polyclonal hyper-IgA than those with the IgG type or IgM type. The sera from the patients with IgG or IgM type M-proteinemia had FRA only at the position of albumin, but 11 of 13 sera with IgA type M-proteinemia stained for glycoprotein at the position of the M-protein band as well as the albumin band. The abnormal precipitin arcs of IgA-albumin complex were observed in 11 of 13 sera from patients with IgA type M-proteinemia that were glycosylated at the position of M-protein band.     

Differential binding of IgA proteins of different subclasses and allotypes to Staphylococcal protein A.

The binding of myeloma proteins of known subclass and allotype to staphylococcal protein A has been studied using affinity chromatography with Protein A-Sepharose CL-4B. Three IgA1 proteins did not show any binding, whereas two IgA2 A2m(1) and one IgA2 A2m(2) proteins were found to bind to the column.     

小鼠卵丘透明质酸结合蛋白的分布

目的：观察小鼠卵丘细胞外基质透明质酸结合蛋白（HABPs）的分布,探讨HABPs对小鼠卵丘的结构和功能的影响。方法：应用免疫荧光双重染色检测HABPs在野生型和bikunin基因敲除小鼠卵丘细胞外基质中的表达。结果：HABPs在两型小鼠卵丘细胞外基质呈阳性表达,HABPs的缺失损害小鼠卵丘细胞外基质完整。结论：HABPs对卵丘细胞外基质的完整是必需的。     

Normal neuroanatomical variation due to age: the major lobes and a parcellation of the temporal region

We used high-resolution MRI to investigate gray and white matter aging in the major lobes of the cerebrum (frontal, parietal, temporal, occipital) and the major sectors of the temporal lobe (temporal pole, superior temporal gyrus, infero-temporal region, parahippocampal gyrus, amygdala, hippocampus). Subjects included 87 adults between the ages of 22 and 88 years. Regions of interest were hand-traced on contiguous 1.5mm coronal slices. For the cerebrum in general, gray matter decreased linearly with age, resulting in a decline of about 9.1-9.8% between the ages of 30 and 70 years, and a decline of 11.3-12.3% by the age of 80. In contrast, white matter volume increased until the mid-50s, after which it declined at an accelerated rate. At 70 years, white matter volume was only 5.6-6.4% less than at 30 years, but by age 80, a cubic regression model predicted that the decrease would be 21.6-25.0%. Multivariate analyses indicate that the frontal gray matter was most strongly associated with age, while occipital gray and white matter were least associated. Reduction in volume in the hippocampus was best modeled by a cubic regression model rather than a linear model. No sex differences in aging were found for any regions of interest.     

Failure to genotype Human Cytomegalovirus by PCR-RFLP method due to sequence variation within the primer binding site

Polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) is one of the rapid methods for genotyping Human Cytomegalovirus (HCMV). When genotyping clinical samples by a sensitive nested PCR-based RFLP method for the glycoprotein B (gB) gene of HCMV, it was found that some of the clinical specimens did not give an amplification signal. Analysis of the prototype sequences of the different genotypes showed base pair mismatches over the primer binding site. An alternative assay is suggested for genotyping of HCMV.     

Proteolipid proteins: structure and genetic expression in normal and myelin-deficient mutant mice

Myelin, the unique product of a glial cell membrane that electrically insulates the nerve axon, is composed of relatively few major protein components. The recent characterization of these proteins by molecular cloning techniques has raised interest in studies of myelin formation at the molecular level. Proteolipids, a family of integral membrane proteins specific to myelin of the central nervous system, are highly abundant and serve a structural function in the architecture of the multilayered sheath. A critical role for proteolipid protein (PLP) expression during normal development and for the survival of the myelinating oligodendrocyte is reflected in severe developmental disorders of mice that result from genetic mutations in the single structural gene for PLP. The analysis of PLP gene expression in these mutants and other dysmyelinating mouse strains has revealed interactions between myelin-specific genes that may underlie the coordinate development of oligodendrocytes and myelination in the brain.     

Renal concentrating ability in mice: A model for the use of genetic variation in elucidating relationships between structure and function

Summary In Os/+ mice of the XVIII strain, nephron number was reduced by 80% and GFR by 50%. Plots of (U/P)_Osm against percentage filtered solute load excreted showed that the consequent osmotic diuresis per nephron was a sufficient explanation for the mild concentrating defect in XVIII Os/+ mice. This conclusion was confirmed by the fact that subtotal nephrectomy mimicked the effect of the Os gene in this strain. However the same experiments demonstrated that there was an additional qualitative impairment of the renal concentrating mechanism in mice of the DI strain having oligosyndactyly (DI Os/+). Observations on a genetically segregating backcross generation showed that a reduction in mean length of short loops of Henle, but not the absence of a pars recta of the proximal tubule, was probably responsible for the severe concentrating defect in DI Os/+ mice. The usefulness and specific limitations of genetic variation in physiological investigations are discussed.     

Immunization with major outer membrane proteins in experimental salmonellosis of mice.

Porin (outer membrane protein) preparations extracted from a rough (Rb2) mutant of Salmonella typhimurium proved to be good immunogens in mice and rabbits. The antibody response achieved was measured by using enzyme-linked immunosorbent assay techniques. High titers of both antiporin and antilipopolysaccharide were detected in both species. The rabbit antiserum raised against the porins and the porin preparations themselves had a highly significant protective capacity against intraperitoneal Salmonella infection of mice. Absorption of the rabbit antiporin serum with lipopolysaccharide immunosorbent did not change its protective capacity in a passive immunization experiment, suggesting that the antiporin antibody preparations were the active components.     

Association between exposure to farming, allergies and genetic variation in CARD4/NOD1

BACKGROUND: Caspase recruitment domain protein (CARD) 4 has been recently identified as an intracellular pattern recognition receptor that interacts with muropeptides found in common Gram-negative bacteria. We therefore aimed to explore whether the previously observed inverse association between exposure to microbial products and asthma and allergies in childhood is modified by genetic variation in CARD4. METHODS: We genotyped 668 children [mean age 9.3 (SD 1.5) years] enrolled in the cross-sectional ALEX study for seven haplotype tagging single nucleotide polymorphisms in CARD4. We studied the association of asthma, hay fever and allergen-specific serum immunoglobulin E with exposure to a farming environment and with levels of endotoxin and muramic acid measured in house dust samples. We tested whether these associations differed between the genotypes of the polymorphisms under study. RESULTS: A strong protective effect of a farming environment on allergies was only found in children homozygous for the T allele in CARD4/-21596, but not in children carrying the minor allele (C). Among the former, farmers' children had a significantly lower frequency of sensitization against pollen (5.8%), hay fever (1.7%) and atopic asthma symptoms (1.7%) compared with children not living on a farm (19.4%, 13.0% and 7.6%, P<0.01, <0.01 and <0.05, respectively). Conversely, no significant difference in prevalence of these phenotypes by farming status was found among children with a C allele in CARD4/-21596 (14.3%, 7.1% and 8.0%vs 16.5%, 9.0% and 5.7%, respectively). CONCLUSION: Polymorphisms in CARD4 significantly modify the protective effect of exposure to a farming environment.     

Different genetic control of cutaneous and visceral disease after Leishmania major infection in mice

The mouse strains BALB/cHeA (BALB/c) and STS/A (STS) are susceptible and resistant to Leishmania major-induced disease, respectively. We analyzed this difference using recombinant congenic (RC) BALB/c-c-STS/Dem (CcS/Dem) strains that carry different random subsets of 12.5% genes of the strain STS in a BALB/c background. Previously, testing the resistant strain CcS-5, we found five novel Lmr (Leishmania major response) loci, each associated with a different combination of pathological and immunological reactions. Here we analyze the response of RC strain CcS-16, which is even more susceptible to L. major than BALB/c. In the (CcS-16 x BALB/c)F(2) hybrids we mapped three novel loci that influence cutaneous or visceral pathology. Lmr14 (chromosome 2) controls splenomegaly and hepatomegaly. On the other hand Lmr15 (chromosome 11) determines hepatomegaly only, and Lmr13 (chromosome 18) determines skin lesions only. These data confirm the complex control of L. major-induced pathology, where cutaneous and visceral pathology are controlled by different combinations of genes. It indicates organ-specific control of antiparasite responses. The definition of genes controlling these responses will permit a better understanding of pathways and genetic diversity underlying the different disease phenotypes.