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.     

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).     

A new variant of the Es-4 locus in the rat

A new variant of kidney esterase in the DK/Nac rat strain is reported. The new esterase was tentatively named ES-4C determined by a third allele of the Es-4 locus of Linkage Group V (LGV). Strain distribution was surveyed using 17 inbred strains, but no strain except for the DK/Nac strain possessed the ES-4C type. Although we surveyed outbred stocks (Jcl: Wistar and Jcl: SD) we could not find rats carrying the ES-4C type. Genetic analysis of the ES-4C type was carried out using mating experiments between DK/Nac and BUF/Nac (ES-4B). The results indicated that the new variant was controlled by the Es-4 locus and it was named the Es-4c allele.     

用DNA指纹图技术分析Wistar大鼠的遗传距离

采用JL-02多位点探针和Southern杂交对Wistar大鼠基因组进行了DNA指纹分析,并对国内最具有典型的6个地区9个Wistar大鼠群体内和群体间进行了DNA指纹分析比较。结果表明,DNA指纹图较好地反映了封闭群动物的遗传本质,具有良好的多态性。同一群体不同个体间Wistar大鼠遗传距离主要为0.2~0.6,将不同群体的Wistar大鼠DNA指纹图带进行分析表明,所有群体间的DNA指纹图的遗传距离在0.2~0.7。 Abstract:DNA fingerprinting of Wistar rat were studied with JL-02 Mulilocus probe and Southern hybridization,and comparing with different individuals of nine groups Wistar rat from six national classical area and different groups.It was indicated that DNA fingerprinting could reflect genetic material of outbred strain rat,and were more polymorphic.The genetic distances of Wistar rat were distributed for 0.2~0.6 among different individuals within same groups,and the genetic distances of Wistar rat were distributed for 0.2~0.7 among different groups．     

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).     

Slc:Wistar outbred rats show close genetic similarity with F344 inbred rats

Although Slc:Wistar rats are used widely in biomedical research as outbred rats, close similarities in growth curves, survival rates, and immunological and biochemical phenotypes have been reported between Slc:Wistar and F344 inbred rats. We reported previously that nine genetic variations that were fixed in Slc:Wistar rats had identical genotypes in F344 rats. Here, we examined the genetic characteristics of Slc:Wistar rats using 27 simple-sequence length polymorphism (SSLP) markers and compared them with other Wistar stocks available in Japan and with some F344 strains. Among 27 SSLP loci, 23 (85%) were fixed in the Slc:Wistar rats, which was the highest among the other Wistar stocks. The 23 fixed loci shared identical genotypes with corresponding loci in F344 rats. Further, the predominant allele types in the unfixed loci had allele frequencies as high as 80%, and these alleles were identical in the F344 rats. When the nine genetic variations reported previously are added, a total of 32 (89%) out of the 36 loci examined were fixed and identical in the Slc:Wistar and F344 rat genomes. These findings indicate the low genetic variation in Slc:Wistar rats and the high genetic similarity between the Slc:Wistar and F344 inbred rats. This study demonstrates the importance of characterizing outbred rats and the need to pay ample attention to the genetic characteristics the Slc:Wistar rats for their proper use.     

Trends in heterozygosity in the process of producing inbred strains of Japanese quail

Trends in heterozygosity in the process of producing inbred strains of Japanese quail were examined through the characterization of protein polymorphisms based on gene frequencies of 7 polymorphic loci. The average heterozygosity ( H _o) at generation 1 was 0.472 and it decreased with increasing inbreeding coefficient (F) to 0.214 at generation 5 when F was 0.594. In all generations, the observed heterozygosities of the surviving families tended to be higher than those of the families that did not survive. The frequency of heterozygotes of the Es-4 locus in surviving families was higher than that of the extinct families in each generation and the difference became conspisuous in generation 4. These results suggests that a heterozygote advantage of Es-4 locus is revealed by inbreeding.     

中国昆明小鼠亚群蛋白质多态性的研究

本文报道采用电泳技术对北京、上海、长春3市的4个中国昆明小鼠(简称KM)实验群体中24个蛋白质标志研究的结果,与我国1981年从美国引进的NIH小鼠进行比较,显示出:(1)KM小鼠亚群间等位基因组成无明显差异,它们间遗传距离为0.008—0.027,与群体封闭时间成正相关;(2)4个KM小鼠群体间聚类分析发现S:KM群体为特殊一类,该结果与KM亚群间下颌骨分析结果相符;(3)KM与Swiss来源的NIH小鼠群体间在E(?)-3、Es-10、Got-2、Glo-1、Gpt-1、和Mpi-1座位上的等位基因组成存在显著差异,它们之间的遗传距离平均值为0.131±0.011,证实中国KM小鼠为非Swiss来源的一个亚种。     

Screening of inbred rat strains for electrophoretic protein polymorphisms

Nineteen inbred strains of the laboratory rat (Rattus norvegicus) were investigated for genetic differences by starch and agarose gel electrophoretic techniques. For six out of 21 loci, interstrain differences were observed: Tf, 6PGD, Es-1, Es-4, Es-5, and Svp. The variants are briefly described and the allelic distributions are tabulated. The 6GPD locus was found to be linked neither to the major histocompatibility gene region nor to the coat color genes c, a, h.This investigation was supported by the Deutsche Forschungsgemeinschaft (Be 352/10 and Gu 105).     

Biochemical genetics of rat esterases: Polymorphism,tissue expression,and linkage of four loci

Two alleles at each of four esterase loci in Rattus norvegicus are described with regard to tissue expression, electrophoretic characterization, and genetic linkage. A previously described dominant gene for prealbumin serum esterase is demonstrated to exist as two codominant alleles in the genetically determined absence of the characteristic albumin esterase. The allelic composition of 16 inbred strains for four esterase genes is provided, and the heretofore ambiguous nomenclature of rat esterase genetics is standardized. Linkage of Es-1, Es-2, and Es-3 is demonstrated. Es-2 and Es-3 are tightly linked in that no recombination has been observed in 55 offspring. The same offspring demonstrated 9% recombination between Es-1 and the other two loci.This work was supported by a grant from the Brown-Hazen Fund of Research Corporation.     

Genic heterogeneity and genetic monitoring of mouse outbred stocks.

An outbred stock of Swiss:SE mice has been surveyed for genic heterogeneity at 12 loci, encoding biochemical polymorphisms in mice. Using horizontal starch-gel electrophoresis, 6 loci (Es-1, Es-2, Es-3, Es-5, Trf, Dip-1) revealed no genic heterogeneity within the total sample of 289 male mice examined. The other 6 loci (Mpi-1, Mup-1, Hbb, Gpi-1, Pgm-1, Ldr-1) each showed a 2-allelic variation within each of the 3 stock units (pavillions) involved. A pavillion effect on the observed genotype numbers was found for Pgm-1 and Gpi-1 (P less than 0.10). Inadequate genotyping may have occurred at Gpi-1 and Ldr-1, as suggested by a 'week effect' on the observed genotype numbers (P less than 0.05). For studying long-term genetic changes within outbred stocks, a routine monitoring procedure using biochemical polymorphisms is recommended.     

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.     

Genetic relationships among Chinese pigs and other pig populations from Hunan Province, China

In this study, protein-level polymorphisms of transferrin, pre-albumin, hemopexin, ceruloplasmin and amylase were investigated in Hunan native pigs and Large Yorkshire pigs collected from Hunan (a province of China), allowing calculations of allele frequencies, average heterozygosities, inbreeding coefficients and genetic distances. The genetic relationship between Southeast Asian native pigs and American pigs was more distant than those among Southeast Asian native pig breeds. The genetic relationship between Southeast Asian native pig breeds and Hampshire pigs was the most distant.     

A new variant of the Es-1 locus in the rat

A new prealbumin plasma esterase was demonstrated by the use of miniaturized polyacrylamide slab gel electrophoresis. Genetic analysis indicated that the new variant is controlled by the Es-1 locus and this gene was designated Es-1c. Among 11 rat strains only one strain, WJ, possessed the gene. Two random-bred stocks, Jcl:Wistar and Jcl:SD, also maintained it in their populations. Miniaturized polyacrylamide slab gel electrophoresis showed that the ES-1 band consisted of two close bands with the cathodal one staining darker.     

Esterase-7, a common constituent of numerous mouse tissues.

1. Electrophoretic and staining techniques for the relatively specific demonstration of esterase-7 in mouse tissues are described. Esterase-7 was found to be a common constituent of most mouse tissues. 2. The electrophoretic polymorphisms determined by three alleles a, b and c were studied in nine mouse strains. 3. The banding pattern of esterase-7 is being described and the isoelectric points of the allelic bands are being estimated. 4. Recombination studies on a further 129 animals confirmed that the Es-7 locus is tightly linked to Es-2 and Es-11. 5. Esterase-7 precipitates with antiesterase-2 from the rabbit. 6. It differs from esterase-2 by its individual substrate preference and by its susceptibility to inhibition by acylating agents.     

Electrophoretic variation and differentiation in four strains of domesticated rainbow trout (Salmo gairdneri).

A total of 1462 rainbow trout (Salmo gairdneri Richardson) representing four California domestic strains, were examined electrophoretically at 24 gene loci to investigate the amount of genetic variability within strains and genetic differentiation between strains, relative to wild populations. Estimated heterozygosities of 0.071 to 0.134 were similar to those reported for wild populations and thus indicated that the domestic strains were at least as variable as wild populations. Genetic distances between strains ranged from 0.011 to 0.067, values typical of the level of differentiation observed between local conspecific populations in a variety of organisms. It was suggested that this high level of heterozygosity is due to mixing of populations in the strains' histories and perhaps also to balancing selection.     

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.     

Behavior and Genetic Variation in Natural Populations

An analysis of allelic variation at genetic loci controllingseveral esterases and hemoglobin, as demonstrated by electrophoresis,indicates that wild populations of the house mouse (Mus musculus)are characterized by fine-scale genetic subdivision, which,through the territorial behavior of family groups (tribes),is achieved even in the absence of physical or ecological barriersto migration. Heterogeneity in allele frequencies among samples from farmsin the same region and from barns on the same farm was demonstrated.Spatial variation in allele frequencies within single barns,involving a clustering of like genotypes, was shown by grid-trapping,thus providing direct evidence of tribal subdivision in continuouslydistributed populations. For two loci, Es-3 and Hbb, an excess of heterozygotes appearedin samples from small populations, while a deficit characterizedsamples from large populations. The evolutionary significance of subdivision and consequentdrift in house mouse populations cannot properly be evaluatedat this time. Although stochastic processes may play the dominantrole in determining, at a given locus, the genotypes of individualsand frequencies of alleles in small populations, geographicpatterns of variation, as studied in Texas, are characterizedby uniformity of allelic frequency in major physiographic orclimatic regions, as would be expected if selection is determiningthe frequencies.     

GENETIC DIVERSITY AND POPULATION STRUCTURE IN CAMELLIA JAPONICA L. (THEACEAE)

Camellia japonica is a widespread and morphologically diverse tree native to parts of Japan and adjacent islands. Starch gel electrophoresis was used to score allelic variation at 20 loci in seeds collected from 60 populations distributed throughout the species range. In comparison with other plant species, the level of genetic diversity within C. japonica populations is very high: 66.2% of loci were polymorphic on average per population, with a mean number of 2.16 alleles per locus; the mean observed and panmictic heterozygosities were 0.230 and 0.265, respectively. Genotypic proportions at most loci in most populations fit Hardy-Weinberg expectations. However, small heterozygote deficiencies were commonly observed (mean population fixation index = 0.129). It is suggested that the most likely cause of the observed deficiencies is population subdivision into genetically divergent subpopulations. The overall level of population differentiation is greater than is typically observed in out-breeders: The mean genetic distance and identity (Nei's D and I) between pairs of populations were 0.073 and 0.930, respectively, and Wright's Fst was 0.144. Differences among populations appeared to be manifested as variation in gene frequencies at many loci rather than variation in allelic composition per se. However, the patterns of variation were not random. Reciprocal clinal variation of gene frequencies was observed for allele pairs at six loci. In addition, principal components analysis revealed that populations tended to genetically cluster into four regions representing the geographic areas Kyushu, Shikoku, western Honshu, and eastern Honshu. There was a significant relationship between genetic and geographic distance (r = 0.61; P < 0.01). Analysis of variance on allozyme frequencies showed that there was approximately four times as much differentiation among populations within regions, as among regions. It is likely that the observed patterns of population relationships result from the balance between genetic drift in small subpopulations and gene flow between them.     

Strain Differences in Superovulatory Response, Embryo Development and Efficiency of Transgenic Rat Production

The differences between rat strains in superovulation response, in vitro and in vivo development of preimplantation embryos and overall transgenic efficiency was studied. The protocols for induction of superovulation using single injections of pregnant mare’s serum gonadotropin (PMSG) or minipumps with follicle stimulating hormone (FSH) were compared in Lewis (LEW), Wistar-Kyoto (WKY), and stroke-prone spontaneously hypertensive rats (SHRSP) or Sprague–Dawley (SD) and Wistar rats as representative inbred or outbred strains, respectively. The percentage of mated animals with positive superovulatory response was similar in all strains (60.0–100%). The mean number of ova per donor was not dependent on the kind of hormonal treatment used within each rat strain. In general, females from outbred SD and Wistar rats were more responsive to hormonal treatments than animals from inbred rat strains. In addition, SD female rats produced a significantly higher number of embryos per female in response to PMSG-treatment compared to all other strains. Between the inbred strains, SHRSP was the most effective for superovulation. In vitro development of intact zygotes to the blastocyst stage was not different between SD, Wistar and SHRSP rats. In contrast, in vitro development of WKY zygotes was significantly less efficient than in other strains. However, 2-cell stage embryos in vivo produced from SD, SD × Wistar and WKY animals showed no difference in competence to develop to blastocyst stage in vitro. The proportion of offspring developing after oviduct transfer of intact zygotes was similar in all strains (44.0–56.4%) with the exception of WKY rats (35.9%). We also compared the survival rate after injection, ability of manipulated zygotes to develop to term and overall transgenic efficiency in various rat strains. SD and SHRSP zygotes survived after microinjection better than the WKY and Lewis zygotes. No differences were found in the efficiency of transgene integration per newborn in different strains ranging from 5.7 to 16.7%. The results of this study demonstrate that different rat strains have varying responses to superovulation, sensitivity to microinjection, capability to develop in vitro until blastocyst stage or in vivo to term after transfer to foster mothers. Despite these differences all studied strains can be used for efficient transgenic rat production.