Pas1 is a common lung cancer susceptibility locus in three mouse strains

Inherited predisposition to lung cancer is a phenotypic trait shared by different mouse inbred strains that show either a high or an intermediate predisposition. Other strains are instead genetically resistant. The Pas1 locus is the major determinant of lung cancer predisposition in the A/J strain (Gariboldi et al. 1993). To define the determinants of susceptibility to lung tumorigenesis in the highly susceptible SWR/J and in the intermediately susceptible BALB/c mice, we analyzed (BALB/c × SWR/J)F₂ and (BALB/c × C3H/He)F₂ crosses by genetic linkage experiments. The present results provide unequivocal evidence that the same Pas1/+ allele that leads to lung cancer predisposition is shared by A/J, SWR/J, and BALB/c strains. The intermediate susceptibility of the BALB/c strain would result by interaction of Pas1 locus with lung cancer resistance loci. Received: 18 April 1997 / Accepted: 15 June 1997     

High-resolution linkage map in the vicinity of the Lp locus

Looptail (Lp) is a mutation that profoundly affects neurulation in mouse and is characterized by craniorachischisis, an open neural tube extending from the midbrain to the tail in embryos homozygous for the mutation. Lp maps to the distal portion of mouse chromosome 1, and as part of a positional cloning approach, we have generated a high-resolution linkage map of the Lp chromosomal region. For this, we have carried out extensive segregation analysis in a total of 706 backcross mice informative for Lp and derived from two crosses, (Lp/ + X SJL/J)F1 X SJL/J and (Lp/ + X SWR/J)F1 X SWR/J. In addition, 269 mice from a (Mus spretus X C57BL/6J)F1 X C57BL/6J interspecific backcross were also used to order marker loci and calculate intergene distances for this region. With these mice, a total of 28 DNA markers corresponding to either cloned genes or anonymous markers of the SSLP or SSCP-types were mapped within a 5-cM interval overlapping the Lp region, with the following locus order and interlocus distances (in cM): centromere-D1Mit110 / Atp1β1 / Cd3ζ / Cd3η / D1Mit145 — D1Hun14 / D1Mit15 — D1Mit111 / D1Mit112 — D1Mit114 — D1Mit148 / D1Mit205/ D1Mit36 / D1Mit146 / D1Mit147 / D1Mit270 / D1Hun13 — Fcgr2 — Mpp — Apoa2/Fcer1γ - Lp - D1Mit149 / Spna1/Fcer1α-Eph1-Hlx1/D1Mit62. These studies have allowed the delineation of a maximum genetic interval for Lp of 0.5 cM, a size amenable to physical mapping techniques.     

Enzyme markers in inbred rat strains: Genetics of new markers and strain profiles

Twenty-six inbred strains of the laboratory rat (Rattus norvegicus) were examined for electrophoretic variation at an estimated 97 genetic loci. In addition to previously documented markers, variation was observed for the enzymes aconitase, aldehyde dehydrogenase, and alkaline phosphatase. The genetic basis of these markers (Acon-1, Ahd-2, and Akp-1) was confirmed. Linkage analysis between 35 pairwise comparisons revealed that the markers Fh-1 and Pep-3 are linked. The strain profiles of the 25 inbred strains at 11 electrophoretic markers are given.     

Genetic variation of an acid phosphatase (Acp-2) in the laboratory rat: Possible homology with mouse AP-1 and human ACP2

A genetic locus controlling the electrophoretic mobility of an acid phosphatase in the rat (Rattus norvegicus) is described. The locus, designed Acp-2, is not expressed in erythrocytes but is expressed in all other tissues studied. The product of Acp-2 hydrolyzes a wide variety of phosphate monoesters and is inhibited by l(+)-tartaric acid. Inbred rat strains have fixed either allele Acp-2^a or allele Acp-2^b. Codominant expression is observed in the respective F₁ hybrids. Backcross progenies revealed the expected 1:1 segregation ratio. Possible loose linkage was found between the Acp-2 and the Pep-3 gene loci at a recombination frequency of 0.36±0.06.Supported by the Deutsche Forschungsgemeinschaft (Grant Be 352/15) and by a grant from the Alexander-von-Humboldt-Stiftung (VB2-FLF).     

Linkage relationships of peptidase-7, Pep-7, in the mouse

An electrophoretically detectable variant of peptidase-7 in Mus musculus has been found and used to locate the structural gene, Pep-7, on chromosome 5. Gene order and recombination frequencies are estimated as Pep-7 3.5±2.0 Rw 8.8±2.2 go 20.0±4.6 bf.     

Linkage of Pgm-3 in the house mouse and homologies of three phosphoglucomutase loci in mouse and man

The discovery of a third phosphoglucomutase locus (Pgm-3) in the house mouse is reported. Three alleles are recognized on the basis of differences in electrophoretic mobility and enzymatic activity. Pgm-3 ^a (fast mobility and high activity) is present in inbred strain C57BL/10J and 24 other strains; Pgm-3 ^b (slow mobility and high activity) is present in LP/Pas and six other strains; and Pgm-3 ^c (no detectable activity in any tissue tested) is present in strain DBA/2J and 14 other strains. Seventy-four recombinant inbred strains derived from progenitors that differed at Pgm-3 were used to study genic linkage. Pgm-3 is on chromosome 9 and is linked to Sep-1, d, Mod-1, and Ltw-3. Gene order and recombination frequencies are estimated as d 3.8±1.8% Pgm-3 2.3±1.2% Mod-1. Substrate specificities and cofactor requirements show that mouse Pgm-1 is homologous with human Pgm-2, mouse Pgm-2 with human Pgm-1, and mouse Pgm-3 with human Pgm-3.This research was supported in part by NIH Research Grant GM18684 from the National Institute of General Medical Sciences to B.A.T. and by grants from NIH A105531-02 and the Volkswagon Foundation to Jan Klein. J.H.N. was a recipient of a Fellowship from the Max-Planck-Gesellschaft, Munich. G.S. and J.K. were supported by funds from the Deutsche Forschungsgemeinschaft.     

Interstrain differences in bitter taste responses in mice

Interstrain differences in bitter taste responses were examinedusing inbred strains of mice. Taste responses were recordedfrom the glossopharyngeal and chorda tympani nerves of SWR/J,LP/J, BDP/J and DBA/2J mice. There were large differences inthe magnitude of responses to sucrose octaacetate (SOA) in boththe glossopharyngeal and chorda tympaninerves of SWR/J miceas compared with the other strains of mice. SOA thresholds ofSWR/J mice were 10^–7–^–6 M, whereas they were– 10^–4 M in LP/J mice. On the other hand, no appreciabledifferences were observed in the responses to quinine hydrochlorideand pnenyl-thio-carbamide. The results obtained in the presentexperiments fully explain the findings in behavioral studiesshowing that only SWR/J mice avoid SOA solutions whereas otherstrains do not. ^*Present address: Department of Physiology, Niigata UniversitySchool of Dentistry, Niigata 951, Japan     

Linkage of isozyme loci in the mouse: Phosphoglucomutase-2 (Pgm-2), mitochondrial NADP malate dehydrogenase (Mod-2), and dipeptidase-1 (Dip-1)

The linkages of the isozyme genes Mod-2, Pgm-2, and Dip-1 have been determined in tests with established linkage group markers among inbred strains of mice. Unique alleles for both Mod-2 and Pgm-2 have been observed in the strain of SM/J. Linkage was determined from backcross progeny of the matings C57BL/6J×(SM/J×C57BL/6J)F₁, (SM/J×SWR/J)F₁×SM/J, and (SM/J×SWR/J)F₁×SJL/J. The gene Mod-2 is on linkage group 1. In a three-point cross of the loci Gpi-1, c, and Mod-2, the c locus was determined to be the middle gene. No double crossovers were observed. Our combined data show the following linkages: Gpi-1 to c, 28.3±3.2%; Gpi-1 to Mod-2, 33.3±3.0%; and c to Mod-2, 4.1±2.8%. The proposed gene order for four markers on LG I is Gpi-1-p-c-Mod-2. The gene Pgm-2 was linked to Gpd-1 (27.0±4.2%) on LGVIII. Two backcrosses segregating for Pgm-2 and b, (SM/J×DBA/2J) F₁×DBA/2J and (SM/J×DBA/2J)F₁×C57BR/cdJ, showed 9.1±4.3% recombination. The proposed gene order on LG VIII is b-Pgm-2-Gpd-1. The genes Pgm-1 and Pgm-2 are not linked (53.4±4.4%). Linkage of the isozyme genes Dip-1 and Id-1 on LG XIII was observed in backcross progeny of the crosses (SJL/J×C57BL/6J)F₁×SJL/J and C57BL/6J×(SM/J×C57BL/6J)F₁. The combined recombination was 23.8±2.8%. Two cases are established where genes whose enzyme products share substrate affinities (Pgm-1 and Pgm-2; Mod-1 and Mod-2) are not linked. Our data generally support the conclusion that functionally or metabolically related isozyme genes are not contiguous on mouse linkage groups.This investigation was supported in part by Public Health Service General Research Support Grant GM-09966 and in part by Public Health Service Training Grant 5T01 HD-00032-07 from the National Institute of Child Health and Human Development, and by Atomic Energy Commission contract AT(30-1)-3671.     

Genetic studies on hexokinase in the mosquitoAedes togoi

Hexokinases (EC 2.7.1.1) were genetically analyzed in the mosquitoAedes togoi by agar gel electrophoresis. Enzyme activity was observed anodally in one major banding region (HK-1) on the gel and in another faintly stained region (HK-2). A total of six bands was detected in the HK-1 region. All six bands could be detected in three body parts, head, thorax, and abdomen, of adults with different banding intensities. The third and fourth bands, numbered from the more anodal side, showed the broadest substrate specificity and the greatest enzyme activity throughout development. Genetic analysis of the six HK-1 bands was undertaken on the hypothesis of a single gene locus (or three extremely tightly linked loci). The analysis gave the following gene order:HK-1—4.2±1.8 (recombination units±SE)—To-2—Odh-2—29.5±2.5—sex (M/m)—s. A comparison is made of gene loci for hexokinases among the mosquito speciesCulex pipiens, Aedes aegypti, and this species, along with a comment on linkage relationships betweenHk andOdh (octanol dehydrogenase) loci in threeAedes species.This research was supported by National Institutes of Health Grant AI 16983 and a Grant-in-Aid for Co-operative Research (57340033) from the Ministry of Education, Science and Culture, Japan.     

Peptidase-3 (Pep-3), dipeptidase variant in the rat homologous to mouse Pep-3 (Dip-1) and human PEP-C

Starch gel electrophoresis and histochemical staining with l-leucyl-l-tyrosine have revealed genetic variation for dipeptidase in Rattus norvegicus. The tissue distribution, substrate specificity, and heterozygous expression as a monmeric protein suggest homology of the variant peptidase to human PEP-C and mouse Pep-3 (Dip-1). We propose Peptidase-3 (Pep-3) as a name for this autosomal locus in the rat. The allele responsible for slower (less anodal) electrophoretic migration is designated Pep-3 ^a and is characteristic of strain ACI/Pit. A faster (more anodal) electrophoretic mobility is the product of the Pep-3 ^b allele in strain F344/Pit. Twenty-five additional inbred strains carry Pep-3 ^a and 16 others carry Pep-3 ^b . Wild rats trapped in Pittsburgh were polymorphic for this locus. Alleles at Pep-3 segregated independently of c (linkage group I), a (linkage group IV), RT2 and Es-1 (linkage group V), h (linkage group VI), and RTI (linkage group VIII).     

A second gene affecting the sialylation of lysosomal α-mannosidase in mouse liver

We have previously reported on a mouse liver-specific genetic polymorphism associated with altered sialylation of lysosomal a-mannosidase. A second electrophoretic polymorphism for liver lysosomal a-mannosidase has now been found and characterized. This variation, between SWR/J and SM/JCv inbred mice, is determined by a single genetic locus (Map-2) on chromosome 17 and appears to be the result of further differences in sialylation of the lysosomal enzyme. The Map-2 gene appears to affect the processing of liver, spleen, and lung lysosomal a-mannosidase, whereas the Map-1 gene appears to be specific to the processing of liver lysosomal a-mannosidase (Dizik and Elliott, 1977). The more negatively charged electrophoretic liver phenotype (MA-A) characteristic of the SM/JCv strain is recessive to the phenotype (MA-B) characteristic of the SWR/J strain. In contrast, at the Map-1 locus, the more negatively charged phenotype is dominant. The electrophoretic pattern of development of the liver enzyme from SM/JCv mice is described.This work was supported in part by Grant GM-19521 from the U.S. Public Health Service. One of the authors (M. D.) was supported in part by USPHS Grant TAO-CA05016.In partial fulfillment of the requirements for the Ph.D. degree.     

Genetic linkage relationships between two enzyme loci,Est-2 and acph,in the mosquito Aedes (Finlaya) togoi

An esterase locus (Est-2), coding for carboxylesterase, and an acid phosphatase locus (Acph) were genetically studied by agar gel electrophoresis in the mosquito Aedes (Finlaya) togoi. The Est-2 and Acph variants occur as a monomer and a dimer, respectively. Both enzyme loci are linked to the sex locus (M) and s (straw-colored larva); the gene arrangement and recombination distances were Est-2—12.6%—s—31.7%—M—2.9%—Acph—3.2%—Est-3. The Est-3 locus was previously shown to code for carboxylesterase.This work was supported by Grant AI 16983-02 from the National Institutes of Health, Bethesda, Md.     

Linkage of lactate dehydrogenase-2, Ldh-2, in the mouse

An electrophoretically detectable variant of lactate dehydrogenase-2 in Mus musculus has been found and used to locate the structural gene, Ldh-2, on chromosome 6. Gene order and recombination frequencies are estimated as Sig—36.0±4.8—Lc 21.0±4.1—Mi ^wh—20.0±4.0—Ldh-2.     

Y-chromosomal factor is involved in neonatal lethality in (♀ DDD × ♂DH-Dh/+) F1-Dh/+ male mice

The dominant hemimelia(Dh) mutation causes various developmental abnormalities in mice. Most -Dh/+ males, crosses between DDD females and DH-Dh/+ males, have lethal abnormalities during the neonatal period. This is a consequence of synergism among three independent gene loci; that is, theDh allele on chromosome (Chr) 1, the DDD allele on an X Chr-linked locus, and a Y Chr-linked locus in some strains. With regard to the Y Chr derived fromMus musculus musculus (M. m. musculus), the Y Chrs of C57BL/6J and BALB/cA caused lethality, but the Y Chr of C3H/HeJ did not, suggesting that not allM. m. musculus Y Chrs are the same. In the present study, whether Y Chrs derived fromM. m. domesticus andM. m. castaneus could cause lethality was investigated. Among seven inbred strains, including AKR/J, DDD, RF/J, SJL/J, SWR/J, TIRANO/Ei, and CAST/Ei, Y Chrs of AKR/ J, DDD, SJL/J, SWR/J, and TIRANO/Ei caused lethality, but Y Chrs of RF/J and CAST/Ei did not. It was unlikely that the mitochondrial genome of the DDD strain contributed to the lethality. The X Chr-linked locus could not compensate for the role of the Y Chr-linked locus. These results suggest that not allM. m. domesticus Y Chrs are the same.     

Relationship between tryptophan biosynthesis and indole-3-acetic acid production in Azospirillum: identification and sequencing of a trpGDC cluster

Summary Screening the tryptophan (Trp)-dependent indole-3-acetic acid (IAA) production of different Azospirillum species revealed that A. irakense KA3 released 10 times less IAA into the medium than A. brasilense Sp7. A cosmid library of strain Sp7 was transferred into A. irakense KA3 with the aim of characterizing genes involved in IAA biosynthesis. Trp-dependent IAA production was increased in two transconjugants which both contained an identical 18.5 kb HindIII fragment from Sp7. After Tn5 mutagenesis, cosmids carrying Tn5 insertions at 36 different positions of the 18.5 kb fragment were isolated and transferred into strain KA3. IAA production by the recipient strains was screened by HPLC. The Tn5 insertions of 4 clones with decreased IAA production were mapped on a 2 kb Sall — SphI fragment. Recombination of Tn5 insertions at this locus into the genome of strain Sp7 led to Trp auxotrophic mutants. A 5.2 kb EcoRI — SalI fragment including the kb SalI — SphI fragment was sequenced and six open reading frames were identified. Three of them were clustered and their deduced amino acid sequences showed significant similarity to TrpG, TrpD and TrpC, which are enzymes involved in tryptophan biosynthesis. One of the remaining open reading frames probably encodes an acetyltransferase. The region responsible for the enhanced Trp-dependent IAA production in strain KA3 corresponded to trpD, coding for the phosphoribosyl anthranilate transferase.     

A new alloantigen expressed selectively on B cells: the Lyb-2 system

The new alloantigenic system of the mouse -Lyb-2-is described, and the strain distribution of the phenotype Lyb-2.1 recorded. So far no antiserum to the alternative Lyb-2.2 or other phenotypes is available. On present evidence, the cell-surface component represented by Lyb-2.1 antigen is expressed only on cells of the B-lymphocyte lineage. Cytotoxicity titers of Lyb-2.1 antisera may exceed 1:640 against spleen cells, with maximal lysis usually around 1:80. In two Lyb-2.1⁺ mouse sublines — CBA/J and C3Hf/Bi — the proportion of spleen cells lysed is lower than in other Lyb-2.1⁺ strains. The position of theLyb-2 locus has not been found, but close linkage with several loci has been excluded.     

Strain differences among mice in taste psychophysics of sucrose octaacetate

SWR/J inbred mice consistently avoided a 10^–4 M sucroseoctaacetate (SOA) solution in unconditioned two-bottle preferencetests whereas mice of all other inbred strains tested did not(confirming a previous report that used SWR mice of a differentsubline). In a conditioned taste aversion procedure SWR/J miceavoided SOA at concentrations from 10^–3 M to 10^–7M but not at 10^–8 M. Various other inbred strains firstfailed to avoid SOA at concentrations from 10^–3 M to 10^–5M. The major strain difference between SWR and other inbredmice was robust across rearing regimes and when tested withother psychophysical procedures. In single-bottle, free-lickingtests SWR/J mice differed from C57L/J mice in response to SOAfollowing extremely brief exposure to the SOA.The SOA detectionthreshold differences indicated by these psychophysical proceduresare also consistent with differences reported from electrophysiologicalrecordings from glossopharyngeal and chorda tympani nerves inmice of several of the same strains.     

Mapping of theLyb-4 gene to different chromosomes in DBA/2J and C3H/HeJ mice

Linkage has been established between the Lyb-4 alloantigen locus and the chromosome 4 markersLyb- 2 andMup- 1 using recombinant inbred (RI) strains. Only 2 of 24 BXD RI strains possess recombinant genotypes with respect to the B cell alloantigen lociLyb- 4 andLyb- 2, for an estimated recombination frequency of 0.024 ±0.019. One additional BXD RI strain was a recombinant with respect toLyb- 4 andMup- 1 (major urinary protein locus) for an estimated recombination frequency of 0.039 ± 0.026. These linkages were confirmed and further quantitated in a (C57BL/6J × DBA/2J)F₁ × C57BL/6J backcross population, in which the recombination frequency betweenLyb- 4 andMup- 1 was 0.049 ± 0.019. No recombination between the expression of Lyb-4.1 antigen and the ability of anti-Lyb-4.1 serum to suppress MLC reactivity was found, indicating that the genes controlling the antigenic determinant which is recognized with cytotoxic antibodies in anti-Lyb-4.1 serum is the same as, or is very closely linked to, the gene which is responsible for augmentation of the MLC response. In contrast, no linkage was observed between the gene controlling the Lyb-4.1 determinant andMup- 1 in RI strain and backcross mice derived from the cross of C3H/HeJ and C57BL/6J. Again, there was complete concordance between the serologically recognized determinant and the ability of anti-Lyb-4.1 serum to suppress the MLC response. Absorption of anti-Lyb-4.1 serum with C3H/HeJ, DBA/2J, and C57BL/6J lymphocytes, followed by the cytotoxic assay of the absorbed sera on lymphocytes of each of these three strains showed that serologically the Lyb-4.1 antigenic determinant on DBA/2 mice was indistinguishable from that on C3H/HeJ mice. Thus, both traits appear to be under the control of single genes in both DBA/2J and C3H/HeJ, but the C3H/HeJ gene appears to be nonallelic and unlinked to the DBA/2J gene.Abbreviations used in this paper LAD lymphocyte activating determinants - LPS lipopolysaccharide - MLC mixed lymphocyte culture - RI recombinant inbred     

Characterization of a new organization of the plantaricin locus in the inducible bacteriocin-producing<Emphasis Type="Italic"> Lactobacillus plantarum</Emphasis> J23 of grape must origin

Lactobacillus plantarum J23 was previously characterized as a bacteriocin-producer-strain when it was cocultured with other lactic acid bacteria. In this work, the genetic organization of the pln locus in the J23 strain was studied and compared with those of previously described L. plantarum C11, WCFS1 and NC8 strains. A new organization of the plantaricin locus was detected in the J23 strain. The sequenced fragment (20,266 bp) comprised plnJLR, plnMNOP, plnEFI, plnGHSTUVWXY, and plNC8IF-plNC8HK-plnD operons, as well as a new region that includes three new orfs (GenBank accession number DQ323671). When the J23 pln gene sequences were compared with those included in the GenBank database, the identity of the putative encoded proteins was in the range 67.1–100%. The regulatory system and the repertoire of putative bacteriocins of the J23 pln locus presented important differences with respect to the ones of C11, WCFS1 and NC8, such as the absence of plnK and the presence of a larger plnJ gene than the previously described for the other L. plantarum strains. The pln locus in L. plantarum strains seems to be a mosaic-like structure with different modules and reorganizations that presents highly conserved regions related to transport and bacteriocin maturation and variable regions related to regulation and bacteriocin production.     

Comparative biochemistry of murine arylsulfatase B

Arylsulfatase B was purified 4500-fold from liver and kidney of C57BL/6J mice. Hepatic and renal arysulfatase B are apparently determined by a single structural locus; however, posttranslational modification introduces inter- and intratissue microheterogeneity. Partially purified enzyme from C57BL/6J, A/J, C3H/HeJ, and SWR/J mice has similar catalytic properties. The 4500-fold-purified arylsulfatase B from SWR/J and C3H/HeJ mice was more thermostable than that from C57BL/6J and A/J mice, strongly suggesting that the thermostability difference reflects an alteration of the primary structure of the enzyme. Thermal stability of arylsulfatase B was pH dependent and markedly influenced by buffer anion. Variation of thermostability did not appear accountable for the observed activity variation among these strains; however, this possibility cannot be rigorously excluded by presently available data. Thirty-five murine strains were found to possess the As-1 ^a allele (thermostable enzyme), while As-1 ^b was largely restricted to A and C57 strains.This research was supported by PHS Biomedical Sciences Research Support Grant RR-07030.