Genetic profile of LIBP/1 inbred strain derived from the Kunming outbred stock of the mouse]

To make the genetic profile of the LIBP/1 inbred strain obtained from Kunming mice, the most widely used outbred stock in China, 26 loci were examined. The genotypes of four kinds of coat color genes were a/a, B/B, c/c and D/D. The results of testing 21 biochemical marker genes showed Akp-1b, Amy-1a, Car-2a, Ce-2a, Es-1b, Es-3a, Es-10a, Es-11a, Gpd-1a, Gpi-1a, Gus-1b, Hbbs, Idh-1a, Ldr-1a, Mod-1a, Mup-1b, Pep-3b, Pgm-a, Sep-1b, Tam-1c, and Trfb. The H-2 gene loci were Kb and Db.     

Effects of cryopreservation of mouse embryos and in vitro fertilization on genotypic frequencies in colonies

To evaluate the effects of cryopreservation and in vitro fertilization (IVF) on genotypic frequencies in mouse colonies, genotypic frequencies at 15 biochemical, 4 immunological and 20 microsatellite loci were examined in three colonies of MCH (ICR) mice derived from noncryopreserved embryos obtained by natural mating without the induction of superovulation, cryopreserved embryos obtained by natural mating with the induction of superovulation, and cryopreserved embryos obtained by the induction of superovulation and IVF. Three (Pgm-1, Ldr-1 and Hbb) out of the 15 biochemical loci, two (Thy-1 and H2K) out of four immunological loci and five (D5Mit18, D6Mit15, D12Mit5, D13Mit26, and D14Mit7) out of 20 microsatellite loci that showed polymorphisms in every colony were used for detection of genotypic frequencies. The genotypic frequencies of the loci in the three colonies did not differ from the predicted genotypic frequencies (P > 0.05). The results suggested that genetic drift does not occur among colonies established from treated and untreated embryos, and it was clear that the embryo banking by cryopreservation is suitable for preservation of outbred stock without genetic drift.     

Genetic drift in an outbred stock of mice.

Survey in protein polymorphism in the nucleus colony of the Him: OF 1-mouse outbred stock showed that 8 of 53 loci were variable in the stock. Allele frequencies of these eight loci (Idh-1, Mup-1, Pgm-1; Ldr-1, Gpi-1s, Hbb, Mod-1, Ce-2) changed between generations investigated. The average percentage of heterozygote animals for these loci decreased with generation. These suggested that genetic drift occurred in the breeding stock. Examination in the breeding record sheets showed that genetic drift was caused by mistakes in mating probably due to repeated personnel changes and insufficient training of the animal technicians. Mice had not been paired according to the schemes prescribed, pairing among relatives and reduction of the number of litters used for mating occurred. The increase in homozygosity showed only little effect on breeding parameters: The interval between pairing and first and second litter increased significantly.     

用19个生化基因位点研究普通级Z:ZCLA长爪沙鼠的遗传多样性

目的调查Z:ZCLA长爪沙鼠原种群普通级长爪沙鼠的遗传多样性。方法用本实验室自行建立的长爪沙鼠19个生化基因位点的乙酸纤维素膜电泳技术并结合基本群体遗传学指标研究了普通级Z:ZCLA长爪沙鼠100个家系的遗传多态性。结果Z:ZCLA长爪沙鼠在Es-1、Car-2、Hbb、Gpi-1、Cs-1、Ce-2I、dh-l、Mod-1呈单态,在Es-2、Es-3、Es-4、Es-6、Es-8、Es-9、Es-10、pd-1、gm-1、Trf、Akp-1个位点上呈现多态性,等位基因从2~4个不等,平均等位基因数3.0,平均杂合度0.512,平均多态信息量0.455。结论提示目前本群遗传多样性水平处于中度多态。     

Linkage of faded gene (fe) to chromosome 6 of the mouse

Linkage tests on the faded gene were carried out with some coat color and biochemical markers, It was shown that the faded locus was not closely linked to the following loci: Idh-1 (chromosome 1), a (2), Car 2 (3), Mup-1 (4), Pgm-1 (5), Hbb (7), Gpi-1 (7), Es-1 (8), Trf (9), Es-3 (11), s (14), Sod-1 (16) and Ce-2 (17). The mutant locus showed linkage with Ggc on chromosome 6.     

Genetic diversity in Cucumis sativus L. assessed by variation at 18 allozyme coding loci

Summary The genetic diversity of the U.S. Cucumis sativus L. germplasm collection [757 plant introductions (PI) representing 45 countries] was assessed using 40 enzymes which represented 74 biochemical loci. Polymorphisms were observed at 18 loci (G2dh-1, Gpi-1, Gpi-2, Gr-1, Gr-2, Idh, Mdh-1, Mdh-2, Mdh-3, Mpi-2, Pepla-2, Peppap-2, Per-4, Pgd-1, Pgd-2, Pgm-1, Pgm-3, and Skdh). Two PIs (285606 and 215589) contained alleles [G2dh-1(1) and Per-4(2), respectively] which did not occur in any other PI. Other alleles which occurred in low frequencies (in < 1% of the PIs) included Gpi-1(3), Gpi-2(3), Gr-1(3), Gr-2(1), Idh(1), Mdh-1(2), Mdh-2(1), Peppap-2(1), and Pgd-1(1). Individual loci containing more than one allele in greater than 20% of the PIs included Mpi-2, Pepla-2, Pgd-2, and Pgm-1. Multivariate analyses aided in the reduction of data (principle components), depicted relationships among PIs (cluster), and identified the most discriminating enzyme loci (Pgm-1, Pepla-2, Gr-1, Pgd-2, Mpi-2, and Skdh) (classification and regression tree).Research partially supported by Asgrow, DeRuiter, Nickerson-Zwaan, Nunhems, and Sun Seed Companies; and the Graduate School, University of Wisconsin, Madison     

Coarse-grained population structure in Central European sculpin (Cottus gobio L.): secondary contact or ongoing genetic drift?

Population genetic affinities of 261 European sculpins Cottus gobio L. across the Rhenanian-Danubian and the Rhenanian-Rhónian watersheds were assessed by horizontal agarose-gel electrophoresis of up to 20 allozyme systems (encoded by 29 genetic loci). Polymorphism P_mean= 0.0689 (range: 0.000-0.1379), and heterozygosity H_e(mean)= 0.0167 (range: 0.000-0.0507) indicated low genetic variability within local stocks from single streams. Significant genetic distances D_mean= 0.1917 ± 0.0336 (D_max= 0.2407), based on differential fixation at 3–6 loci (Acp-1**, Pgdh**, Fh**, Est-1**, Gpi-2**, and Pgm-1**) distinguished populations from the Neckar catchment basin from those of the Hochhrein-Oberrhein and Danube basins. Differential fixation of alleles and pronounced genetic distances also separated sculpins of the Rh6nian tributary Doubs from Neckarian populations (D_men= 0.2131 ± 0.0033; Ah**, Acp-1**, Fh**), of the Doubs from the Danube (D_mean= 0.2177 ± 0.0028; Gpi-2**, Pgm-1**, Pgdh**, Ah**), and of the Doubs from the Hochrhein-Oberrhein (D_mean= 0.1780; Pgm-1**, Pgdh**, Ah**). Genetic distances between streams within these drainages proved low (Neckar: D_men= 0.0047 ± 0.0014, Danube: D_mean= 0.026 ± 0.0179, Rhine: D_mean= 0.0308). Screening of another 16 small-size samples consisting of 55 sculpins for nine diagnostic loci (Aat-2**, Acp-1**, Acp-2**, Ah**, Est-1**, Fh**, Gpi-2**, Pgdh** and Pgm-1**) confirmed the genetic homogeneity of sculpins within the Danubian and Neckarian drainage systems, but Neckarian sculpins were similar to those from the river Main. Populations from Hochrhein-Oberrhein resembled the Danubian stock but contained a decreasing frequency of ‘Neckarian’ markers when approaching the Danubian region. The genetic divergence between Neckarian, Danubian and Rhdnian sculpins suggests the existence of hitherto neglected taxa of anteglacial divergence.     

Effects of marked chromosome sections on quantitative traits in the mouse

Summary An investigation of the influences of marked chromosome sections on quantitative traits in a backcross-generation with 2321 mice (C57BL/6JHan × (AKR/NHan×C57BL/6JHan)) is described. In the animals the chromosomes 1, 4, 7, and 8 were marked by the gene loci Idh-1, Gpd-1, Gpi-1s, Es-1, resp. Within the backcross-generation, for Idh-1 and Es-1, more heterozygous genotypes were found than expected under random conditions. By comparing animal-groups with different homologous sections of the marked chromosomes, effects were observed on quantitative traits (body length and weight, dry weight and matter, fat weight and content). The results indicate that a few chromosome sections influence to a major extent the genetic variation of some quantitative traits.This investigation was supported by the Deutsche Forschungsgemeinschaft (Sonderforschungsbereich 146)     

Gene mapping in Mus musculus by interspecific cell hybridization: assignment of the genes for tripeptidase-1 to chromosome 10, dipeptidase-2 to chromosome 18, acid phosphatase-1 to chromosome 12, and adenylate kinase-1 to chromosome 2.

Chinese hamster X mouse somatic cell hybrids segregating mouse chromosomes were examined for their mouse chromosome content using trypsin-Giemsa (GTG) banding and Hoechst 33258 staining techniques. Simultaneously, they were scored for the presence of 24 mouse enzymes. The results confirm the assignments of 11 genes previously mapped by sexual genetics: Dip-1 and Id-1 to chromosome 1; Pgm-2 and Pgd to 4; Pgm-1 to 5; Gpi-1 to 7; Gr-1 to 8; Mpi-1 and Mod-1 to 9; Np-1 and Es-10 to 14. They also confirm chromosomally the assignments of 3 genes that were made by other somatic cell genetic studies: Aprt to 8; Hprt and alpha-gal to the X chromosome. But most importantly, four enzyme loci are assigned to four chromosomes that until now were not known to carry a biochemical marker which is expressed in cultured cells: Trip-1 to 10; Dip-2 to 18; Acp-1 to 12; and Ak-1 to 2. Cytogenetic examination of clones showing discordant segregation of HPRT and A-GAL, suggested the assignment of alpha-gal to region XE leads to XF of the mouse X chromosome. The cytologic studies provide a comparison between data from sexual genetics and somatic cell hybrids and validate hybrid cell techniques. They provide evidence of the reliability of scoring chromosomes by GTG and Hoechst staining and stress the importance of identifying clones with multiple chromosome rearrangements. Striking examples of norandom segregation of mouse chromosomes were observed in these hybrids with preferential retention of 15 and segregation of 11 and the Y chromosome.     

Genetic polymorphism of the sixth component of complement (C6) in mice

Immunofixation after isoelectric focusing revealed two forms of mouse C6, C6A and C6M, both of which consist of two major protein bands and one or more acidic minor bands. They were distinguishable by their different isoelectric point (pI) ranges: C6M has more acidic pI ranges (pH < 6.2) than C6A (pH < 6.3). C6A was found in common inbred mice of Mus musculus domesticus, while C6M was found in inbred and wild mice of M. m. molossinus (Japanese wild mice, an Asian subspecies). Breeding experiments showed that these two forms of C6 were controlled by a single codominant autosomal locus. We propose the designation C-6 for this locus with two alleles, C-6 ^a and C-6 ^m , which encode for C6A and C6M, respectively. Linkage analysis indicated that the locus is not closely linked to the following loci: Idh-1, agouti, Amy-1, brown, Gpd-1, Mup-1, Pgm-2, Pgm-1, albino, Hbb, Es-1, Mod-1, Sep-1, Es-3, Igh-1, beige, Es-10, Sod-1, and C-3.     

Genetic variability within and between outbred Wistar strains of rats.

The allelic frequencies at 6 isozyme loci (Es-1, Es-2, Es-3, Es-4, Es-Si and Amy-1) were examined in 4 outbred Wistar strains and additionally 2 SD strains as controls. From the allelic frequencies, the averages of the heterozygosities in individual strains and the geometric genetic distances between every pair of all possible strain combinations were calculated. The averages of the heterozygosities in 2 SD strains were both intermediate (around 0.2) and the genetic distance between them was rather short. But among the Wistar strains, the averages of the heterozygosities were highly variable and the genetic relationships among them were very variable in their genetic distances. From these results, it was suggested that the outbred Wistar strains were different each other in their genetic constitutions and that no suggestion was obtained to descriminate genetically the Wistar strains from the SD strains.     

Electrophoretic variation in multiple recessive tester, T, stock mice

The multiple recessive tester stock, homozygous for seven recessive visible markers, has been used since the 1950s in the specific locus test of mutagenicity in the mouse. The stock was developed by W.L. Russell in Oak Ridge, sent to the MRC Radiobiology Unit (Harwell) in 1953 and then passed to Research Triangle Institute (RTI) in 1988. Stocks are maintained by random mating in all three centres. and in addition stocks that have been selected for homozygosity at certain enzyme and protein markers are kept at both Harwell and RTI. The extent of electrophoretic variation was investigated in the random bred tester stocks at Harwell in 1981 and 1990, and in both random bred and fixed tester stocks at RTI in 1990. Altogether 44 loci were scored and eight of these (Acy-1, Es-3, Gpi-1, Hba, Hbb, Idh-1, Mod-1 and Pgd) have been polymorphic in one or more colonies at various times. Three loci (Es-3, Hbb and Mod-1) had low levels of polymorphism in 1981 and had become monomorphic by 1990. Despite this slight loss of variation, overall the tester stocks show considerable variability. The proportion of polymorphic loci and mean heterozygosity is of the same order of magnitude as island populations of wild mice or other isolated random bred laboratory populations. Contamination of tester stocks with other stocks can be ruled out, and thus tester stocks can be considered to be characteristic island populations. The retention of an appreciable amount of genetic variability in tester stocks is of practical importance in designing new mutation tests involving these mice. When using these stocks, care must be taken to ensure that they are homozygous for the loci under test.     

应用微卫星DNA标记对Wistar和SD大鼠封闭群的遗传学研究

封闭群大鼠的遗传质量对其医学生物学实验结果有重要影响,但目前缺乏遗传检测方法和标准.本研究应用6个微卫星标记及其荧光标记一半自动基因分型技术,对北京和上海2家单位分别提供的Wistar和Spague-Darley(SD)大鼠封闭群进行了遗传检测和评估.6个微卫星位点均具有高度多态性,在两大鼠群体共发现等位基因36个,每位点等位基因数5-8个,其多态信息含量(PIC)从0.5892(D11Mgh3)到0.8019(D6Mit1),平均为0.688l.6个位点在Wistar和SD大鼠分别发现25和26个等位基因,其平均期望杂合度分别为O.6260和0.6249.两群体的各组遗传多样性指数间无显著差异.群体间的不同微卫星位点Fst范围0.046l到0.4363.平均为0.2069,表明其遗传分化程度较大;Nei(1972)遗传距离和Nei(1978)无偏遗传距离分别为1.2862和1.2726,表明了2群体之间较大的遗传差异:Hardy-Weinberg平衡检验表明Wistar大鼠在所有检测的6个位点均非常显著偏离Haraly-WeinJaerg平衡,SD大鼠在2个位点(D6Mit1和D11Mgh3)处于遗传平衡状态,且偏离位点均表现为杂合子缺陷.因此研究表明,Wistar和SD大鼠封闭群均具有较好的遗传多样性,且两群体之间有较大的遗传差异和分化程度,分别具有各自不同的遗传特征,偏离Hardy-Weinberg遗传平衡是其繁育过程中较多存在的问题.本研究结果将为两品系大鼠遗传检测方法和标准的建立提供基础资料和依据.     

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.     

Reduction of genetic variability in a hatchery stock of brown trout, Salmo trutta L.

Enzyme gene variability in a lake-dwelling brown trout, Salmo Irulla , population was compared with its hatchery derivative by starch gel electrophoresis. A loss of genetic variability was detected in the hatchery stock founded 16 years ago in comparison to the present day wild stock; of seven originally polymorphic loci ( Aat-4, Ck-l, Gpi-3, G3p-2, Ldh-1, Mclh-2 and Pgm-l ) two, Gpi-3 and Ldh-1 , had become monomorphic. The overall hetero-zygosity was reduced by a third from 6–2% to 4–2%. A comparison between three successive hatchery cohorts indicates a distinction between stock heterogeneity. The decrease in genetic variability is probably attributable to small population size in the founding event with subsequent genetic drift and inadvertent selection during hatchery procedures.     

Genetic variation within and between lines of diabetes-prone and non-diabetes-prone BB rats; allele distribution of 8 protein markers

Twenty-four inbred and 2 outbred lines of the BB rat have been genetically characterized by establishing the allele distribution of 8 monogenic protein markers. The marker genes are: plasma alkaline phosphatase-1 (Alp-1), catalase-1 (Cs-1), carboxylesterases (Es-1, Es-2, Es-14), glyoxalase I (Glo-1), group specific component (Gc), and haemoglobin-beta-chain (Hbb). At least 3 linkage groups are represented by this set of markers. Genetic variation was found both within and between lines. Within-line variation was observed in 4 lines, including the 2 outbred lines. The other 22 lines could be subdivided into 4 groups, each representing a unique allele distribution pattern.     

Occurrence of the heterozygosity at Es-1 locus in a sub-strain of the NZB mice]

In the course of inspection of the biochemical marker genes in inbred strains of mice maintained in our laboratory, a female mouse of the NZB strain was found to be heterozygous for the Es-1 locus. Namely, it was Es-1a/Es-1b type. After this finding, many heterozygous mice were found among her sisters and the descendants. However, these heterozygotes (Es-1a/Es-1b) showed no heterozygosity for other 11 characters, i.e., the 6 biochemical markers (Hbb, Trf, Es-2, Id-1, Mod-1, Gpd-1) and the 5 coat colour markers (A, B, C, D, AND S) were idential as those previously described. It was, moreover, observed that they possessed the immunological characteristics typical of the NZB mice. Therefore, it could be concluded that the heterozygosity had been originated from a single mutation at the Es-1 locus, i.e., from Es-1a to Es-1b or vice versa. With regard to the alleles at the Es-1 locus, an investigation was carried out in two sub-strains of the NZB mice having different breeding history and the followings were clarified. One substrain imported from Karolinska Institute, Sweden, had been fixed with the Es-1a allele and the other imported from England was found to be Es-1b/Es-1b type. The NZB mice which displayed the heterozygosity had been derieved from the Karolinska sub-strain. Importance of biochemical marker genes for inspection of proper maintenance of inbred strains has been discussed.     

Allelic profile at 37 biochemical loci of two inbred strains of the house mouse derived from wild Mus musculus musculus

Two newly established inbred strains derived from Mus musculus musculus, designated PWD/Ph (F29) and PWK/Ph (F33), were examined for their alleles at 37 biochemical loci located on 12 different chromosomes. The allelic pattern showed characteristic differences from those observed in common inbred strains. The genetic distance D between PWK/Ph and PWD/Ph was 0.027, whereas the corresponding values for the genetic distances between PWK/Ph and C57BL/6J, DBA/2J, BALB/cJ and SWR/J were 0.777, 0.721, 0.721 and 0.838 respectively. New allozymes are described as being controlled by the loci Es-23, Pre-2 and Tam-1. The genetic relationship to M.m.molossinus is indicated by identical alleles at six other loci (Es-2, Es-9, Es-10, Es-11, Es-18 and Es-22).     

The genetics of aryl hydrocarbon hydroxylase induction in mice: A single gene difference between C57BL/6J and DBA/2J

Twenty-one inbred strains of mice were surveyed for inducibility of hepatic aryl hydrocarbon hydroxylase (AHH) activity by the carcinogen 3-methylcholanthrene (MC). In 11 strains given MC, AHH activity increased 1.3- to 5-fold (inducible), whereas ten strains responded with a less than 0.5-fold increase (noninducible). Neither the inducible nor the noninducible class was homogeneous, and in each considerable variation was found in both the basal activity of AHH and the response to MC. Strains DBA/2J and C57BL/6J were chosen to represent the noninducible and inducible classes, respectively. In the crosses (C57BL/6 × DBA/2)F₁ × DBA/2 and (C57BL/6 × DBA/2)F₂, inducibility segregated as a single autosomal dominant gene. The gene symbols Ahh ⁱ and Ahh ⁿ are proposed for the alleles present in C57BL/6J and DBA/2J, respectively. No genetic linkage was found between the Ahh locus and the following loci: b, d, Es-1, Es-3, Gpd-1, Hbb, Id-1, Pgm-1, and sex. Some implications of this work in the study of mammalian enzyme induction and chemically induced carcinogenesis are discussed. There is a positive correlation between AHH inducibility and the development of an inflammatory response to the topical application of the carcinogen 7,12-dimethylbenzanthracene.     

Mapping of theEs-4 locus and linear order of esterase genes (linkage group V; LGV) in the rat

There are three different linear orders of esterase loci of linkage group V (LGV) in the rat (Rattus norvegicus). The first is Es-2-Es-3-Es-1, the second Es-3-(Es-2,Es-4)-Es-1, and the third Es-3-Es-2-Es-1-Es-4. We carried out mating experiments to define the order clearly. Linkage analyses of the four esterase loci, Es-1, Es-2, Es-3, and Es-4, were carried out using two inbred strains carrying different alleles at the four loci. Six locus combinations examined in this study were as follows: Es-1-Es-2, Es-1-Es-3, Es-1-Es-4, Es-2-Es-3, Es-2-Es-4, and Es-3-Es-4. The recombination frequencies of each combination were 6.3, 6.3, 6.3, 5.2, 1.8, and 3.4%, respectively. The first recombination between Es-2 and Es-4 was observed. We propose that the esterase loci of LGV be classified into three clusters according to distances between the loci. The linear order of the four loci is shown to be as follows: [Es-3] (cluster II)-3.4 +/- 2.4%-[Es-4-1.8 +/- 1.7%-Es-2] (cluster III)-6.3 +/- 6.1%-[Es-1] (cluster I).