Linkage of one component of the major urinary protein complex of mice to the brown coat color locus

Genetically determined electrophoretic variants of the major urinary protein (Mup) complex in mouse urine

The major urinary protein (Mup-complex) excreted in mouse urine, has been studied electrophoretically both on starch gel and on cellogel. On stargel six anodally migrating protein bands were observed. These bands are designated component 3, 2', 1, and 4 (i.e. two bands) in the order of decreasing mobility toward the anode. The slower protein band of component 4 on starch gel was not observed on cellogel. By testing mouse inbred strains, we were able to dinstinguish five male and four female Mup phenotypes. Test crosses suggested a four-allelic (a, b, c, d,) variation with regard to components 2', 2 and 1: 'group A' strains showed component 1, 'group B' strains components 1 and 2, 'group C' and 'group F' strains none, and 'group D' strains showed components 1 and 2'. Component 3 may be encoded by another Mup locus, although no crossing-over has been observed: presence (A, B, D, and F strains), absence (C strains). Insufficiently reproducible demonstration of the variation with regard to component 4, forced us to exclude this component for strain distinction. The Mup phenotypes described, can be useful for the detection of certain strain contaminations, especially if F1 hybrid Mup phenotypes are distinguishable.

Construction of a BALB/c congenic mouse, C.C3H-Lpsd, that expresses the Lpsd allele: analysis of chromosome 4 markers surrounding the Lps gene

Development of a congenic BALB/c mouse strain that contains a segment of chromosome 4 including the Lpsd allele of the lipopolysaccharide (LPS)-hyporesponsive C3H/HeJ strain is presented. On the basis of LPS-induced spleen cell mitogenesis, macrophage tumor necrosis factor secretion, and tyrosine phosphorylation in vitro and lethality in galactosamine-sensitized mice in vivo, the C.C3H-Lpsd strain provides a model of LPS hyporesponsiveness that is comparable to that of the parental C3H/HeJ strain. Analysis of markers in this region indicates that length of the donor fragment is approximately 5.5 centimorgans. Thus, the C.C3H-Lpsd strain provides an important genetic tool for analysis of markers in this region and for examining functional effects of Lpsd expression on the BALB/c background.

Role of a genetic region on chromosome 4 in the regulation of natural killer cell activity in mice

Natural killer cell (NK) activity is regulated by both the H-2 and non-H-2 genes. Using bilineal congenic HW26C and HW13 mice which differ from the background strain C57BL/6By (B6) in a region of chromosome 4, we investigated the role played by a gene/genes in a segment of chromosome 4 of BALB/cBy on NK cell activity. Percoll separated low density spleen cells from young HW26C and HW13 mice showed a 3.5 fold higher NK activity than the B6. We also observed that the increase in NK activity of HW26C was not due to an increase in the number of NK cells. Using five other bilineal congenics containing different regions of chromosome 4 of BALB/cBy, we observed that the putative gene(s) regulating NK activity may be located between b and IFN-alpha/beta genes of chromosome 4. The level of NK activity of (B6xHW26C)F1 ranked between the HW26C and B6 suggesting that the gene product described is inherited in an incompletely dominant fashion.

Linkage between sperm abnormality level and major urinary protein phenotype in mice

Segregation of sperm abnormality level and the pattern of major urinary proteins (MUPs) were investigated in F2 and B1 hybrid males obtained from crosses involving two contrasting inbred strains of mice: CBA/Kw (Mup-1a1a, 3.3% abnormal sperm) and C57BL/Kw (Mup-1b1b, 21.9% abnormal sperm). In the progeny of both crosses mean levels of abnormal spermatozoa were significantly higher for males typed as Mup-1b1b than for heterozygous Mup-1a1b males. Moreover, all F2 hybrid males showing very high percentages of abnormal sperm were Mup-1b1b homozygotes. Similarly, among B1 males with a high level of deformed spermatozoa, a statistically significant majority were Mup-1b1b genotypes. Our results suggest that at least two genes which influence sperm abnormality level are segregating in these crosses. Both appear to be recessive for high sperm abnormality level, and one shows weak linkage to Mup-1 on chromosome 4.

Decreased major urinary protein in male Bar Harbor 129 REJ dystrophic mice indicates a hormonal deficiency

A significant decrease in major urinary protein (MUP) in adult male Bar Harbor 129REJ dystrophic mice correlated with a marked decrease in the amount of translatable MUPmRNA in the liver. Previous investigations have shown that MUP synthesis is under complex multihormonal regulation suggesting that the dystrophic mouse may have a hormonal deficiency.

Subfamily of submaxillary gland-specific Mup genes: chromosomal linkage and sequence comparison with liver-specific Mup genes

Mouse major urinary proteins (MUPs) are encoded by a family of ca. 35 genes that are expressed in a tissue-specific manner in several secretory organs; in the liver, in the submaxillary, sublingual, parotid and lachrymal glands, and in the skin sebaceous glands. In this paper we describe the isolation of a Mup gene, Mup-1.5a, which is expressed predominantly in the submaxillary gland of BALB/c mice. We show that Mup-1.5a is a member of a subfamily consisting of two closely related genes, both of which are closely linked to the Mup-1 locus on mouse chromosome 4. Mup-1 is the locus of a class of Mup genes (Group 1) expressed in the liver. The complete nucleotide sequence of Mup-1.5a has been determined, and was compared to a previously sequenced Group 1 Mup gene. The comparison shows that the differentially expressed Mup genes are uniformly divergent in exons, introns and in their flanking sequences. The regions of homology extend at least 5 kb into the 5' flanking region of Mup genes.

Genes that modify expression of major urinary proteins in mice

A survey of major urinary proteins (MUPs) from eight BALB/c mouse substrains by isoelectric focusing identified a common pattern with about 10 protein bands in males. One substrain, BALB/cJPt, differed in that it expressed two variant MUP patterns, designated 4.1lo and null. To find the chromosomal location of the gene which determines the 4.1lo phenotype, BALB/cJPt-MUP-4.1lo was crossed with a wild-derived Mus musculus domesticus inbred strain (CLA) that expresses the common BALB/c MUP pattern. The F1 phenotype revealed that the gene(s) controlling the MUP-4.1lo trait was recessive. A restriction fragment polymorphism between these strains found with a MUP cDNA probe allowed us to establish that a gene determining the MUP-4.1lo trait was not linked to the MUP structural genes on chromosome 4. Assays for other chromosomal marker loci revealed that a gene determining the MUP-4.1lo trait, designated Mupm-1, was closely linked to Myc-1 on chromosome 15. To determine the genetic basis of the null trait, BALB/cJPt-MUP-null mice were crossed with BALB/cJPt-MUP-4.1lo mice. A MUP restriction fragment polymorphism between these two lines was tightly linked to a gene or genes involved in determining the MUP-null phenotype. The two variant MUP phenotypes in BALB/cJ mice are determined by separate genes, one of which is located on chromosome 4 and the other on chromosome 15. The chromosomal location of Mupm-1 suggests that it produces a trans-acting factor which regulates MUP expression.

Genes that modify expression of major urinary proteins in mice

A survey of major urinary proteins (MUPs) from eight BALB/c mouse substrains by isoelectric focusing identified a common pattern with about 10 protein bands in males. One substrain, BALB/cJPt, differed in that it expressed two variant MUP patterns, designated 4.1lo and null. To find the chromosomal location of the gene which determines the 4.1lo phenotype, BALB/cJPt-MUP-4.1lo was crossed with a wild-derived Mus musculus domesticus inbred strain (CLA) that expresses the common BALB/c MUP pattern. The F1 phenotype revealed that the gene(s) controlling the MUP-4.1lo trait was recessive. A restriction fragment polymorphism between these strains found with a MUP cDNA probe allowed us to establish that a gene determining the MUP-4.1lo trait was not linked to the MUP structural genes on chromosome 4. Assays for other chromosomal marker loci revealed that a gene determining the MUP-4.1lo trait, designated Mupm-1, was closely linked to Myc-1 on chromosome 15. To determine the genetic basis of the null trait, BALB/cJPt-MUP-null mice were crossed with BALB/cJPt-MUP-4.1lo mice. A MUP restriction fragment polymorphism between these two lines was tightly linked to a gene or genes involved in determining the MUP-null phenotype. The two variant MUP phenotypes in BALB/cJ mice are determined by separate genes, one of which is located on chromosome 4 and the other on chromosome 15. The chromosomal location of Mupm-1 suggests that it produces a trans-acting factor which regulates MUP expression.

The gene family for major urinary proteins: expression in several secretory tissues of the mouse

The major urinary proteins (MUPs) of the mouse are encoded by a multigene family located at the Mup a locus on chromosome 4. Previous investigations have shown that the MUPs are synthesized in the liver, secreted and then excreted in the urine. We have found significant levels of MUP mRNA in several secretory tissues: the liver and the submaxillary, lachrymal and mammary glands. There are striking differences in hormonal and developmental regulation of MUP gene expression in these tissues. Furthermore, each tissue appears to express a characteristic pattern of MUP mRNAs. In particular, the lachrymal glands appear to express an entirely different set of MUP mRNAs. These results are discussed in relation to the organization of the MUP gene cluster and a possible function of the MUPs.

Studies on genetic variation in major urinary protein synthesis in mouse liver

A two- to fourfold difference in the relative rate of total major urinary protein (MUP) synthesis between C57BL/6J and C3H/HeJ female mice has been analyzed at the genetic and molecular levels. The C57BL/6J phenotype is dominant in F1 female progeny of a cross between the two strains. Quantitation of MUP mRNA levels indicates that the rate of synthesis variation does not reflect a change in the concentration of total MUP mRNA. In recombinant inbred strains derived from C57BL/6J and C3H/HeJ progenitors, the rate of synthesis difference segregates as a single genetic determinant that is not linked to the Mup-a locus on chromosome 4. The results suggest an unlinked locus that acts to alter total MUP synthesis without altering total MUP mRNA levels. Two models are proposed to describe the action of this locus, both of which imply some sort of posttranscriptional control of MUP synthesis.

Mapping the structural genes coding for the major urinary proteins in the mouse: combined use of recombinant inbred strains and somatic cell hybrids

We have mapped the multiple (15-25) genes coding for the hormonally regulated major urinary proteins (MUPs) of the mouse by using a cloned cDNA probe. By Southern blot analysis of DNA from Chinese hamster-mouse somatic cell hybrids, all of the MUP genes were found to be on chromosome 4. Different inbred mouse strains showed DNA polymorphism in their MUP Southern hybridization pattern. Analysis of recombinant inbred strains derived from these parent strains has shown that all the polymorphisms are linked to the MUP-a locus on chromosome 4. The combination of these mapping techniques should be applicable to many cloned DNA sequences.

Allelic variation at several different genetic loci determines the major urinary protein phenotype of inbred mouse strains

We have examined the major urinary protein (MUP) phenotype of three inbred mouse strains by one-dimensional isoelectric focusing in acrylamide gels. Each strain gave a distinct pattern of major and minor bands. In the three strains together, seven major and about seven minor bands were observed. F1 phenotypes were intermediate. F2 phenotypes can be explained by recombination between allelic variants at four or more different genetic loci. We propose that variation in MUP phenotype is due in fact, to allelic variation at approximately seven structural gene loci, some of which are linked on chromosome 4. The remainder may or may not be linked to these.

Biosynthesis of the major urinary proteins in mouse liver: a biochemical genetic study

By labeling liver protein in vivo with [3H] leucine, the relative biosynthetic rate has been measured for the major urinary proteins (MUPs), three closely related, androgen-regulated proteins that are synthesized in mouse liver, secreted into the bloodstream, and excreted into the urine. In livers from females of strain C57BL/6J, total MUP synthesis represents about 0.6-0.9% of the total protein synthesis; in males and testosterone-treated females of the same strain, synthesis increases to about 3.5-4.0% of the total. This 4- to 6-fold induction of total MUP synthesis is similar to the androgen-mediated increase in MUP-specific messenger RNA reported by others, and indicates that the previously observed 20- to 25-fold induction of total MUP excretion into urine is generated partly at the posttranslational level. By measuring the ratio of synthesis of the individual MUPs, it was determined that the testosterone-mediated change in the pattern of MUP synthesis, indicating nature, of MUPs excreted. A survey of seven inbred mouse strains revealed polymorphism for the rate of total MUP synthesis in untreated females. Two classes could be distinguished on the basis of a 3-to 5-fold difference in the rate. This variation does not correlate with variation at Mup-a, a locus that controls the ratio of the three MUPs in urine from androgen-induced mice. These findings are consistent with the notion that MUP expression is controlled by a variety of independently assorting genes.

Testosterone: a major determinant of extragenital sexual dimorphism

Sexual dimorphism in selected extragenital tissues is described with emphasis on the molecular basis of the differences. Testosterone rather than 5 alpha-dihydrotestosterone appears to be the major intracellular androgen in organs other than skin and reproductive tract, but other steroid metabolites and their receptors are required to produce the diverse tissue differences observed in males and females. There is also evidence that multiple hormones from several endocrine glands are required to act in concert with androgens to produce and maintain their effects. Although many of the consequences of sexual dimorphism, such as body size and strength, have been evident for centuries, other differences between males and females such as disease incidence, response to drugs and toxins, and the metabolism and assimilation of dietary constituents have only recently been discovered.

Major urinary protein and immunoglobulin allotypes of recombinant inbred mouse strains

Serum and urine samples from seven recombinant inbred mouse strains, derived from a cross between BALB/c and C57BL/6, were examined to determine the immunoglobulin heavy chain (IgCH) and the major urinary protein (MUP) allotypes. CXBG and CXBJ exhibited the same IgCH alleles as did BALB/c; the others resembled C57BL/6, thus providing no evidence of crossover types. Comparison of the Mup and brown coat colour (b) alleles (both on linkage group VIII) revealed that three of the strains resemble BALB/c and two resemble C57BL/6, whereas the CXBE and CXBI strains are crossover types.

Location of the Mup-a locus on mouse linkage group 8

By the use of pintail (Pt) and brown (b) as markers, the location of Mup-a, a locus controlling electrophoretic variation of one of the components of the major urinary protein (MUP) complex, on mouse linkage group VIII has been determined. The order and intervals determined from recombination frequencies in 121 offspring from a back-cross were Pt 4·1 b 6·6 Mup-a.