微卫星DNA标记在近交系大鼠HFJ和MIJ遗传监测中的应用

目的 用24对引物对近交系HFJ和MIJ大鼠的微卫星位点进行多态性分析,并选用近交系Lewis和F344大鼠作为对照,进行比较分析.方法 用传统的酚-氯仿法分别提取4个近交系大鼠MIJ、HFJ、Lewis和F344 的基因组DNA,选取大鼠24个微卫星位点,通过PCR扩增,扩增产物经过非变性聚丙烯酰胺凝胶电泳和银染,根据电泳结果,比较分析4种品系近交系大鼠之间微卫星多态性.结果 4种品系及品系内不同个体的近交系大鼠在24个微卫星位点上的扩增产物均出现一个条带,MIJ和HFJ大鼠在品系间和品系内均表现为单态性,同Lewis 和F344的扩增结果比较,14个位点显示多态性,有10个位点显示单态性.结论 两个近交系大鼠品系MIJ和HFJ符合近交系要求,筛选出的14个多态性微卫星位点可用于有关近交系大鼠的遗传背景监测.     

Predictability of heterozygosity scores and polymorphism information content values for rat genetic markers

Construction of a genetic linkage map of the laboratory rat, Rattus norvegicus, establishes the rat as a genetic model. Allele sizes were reported for 432 simple sequence length polymorphisms (SSLPs) genotyped in 12 different substrains belonging to nine different inbred strains of rats. However, these nine strains represent only a fraction of the more than 140 inbred strains available. If allele sizes are not known, alternative indices of markers' polymorphism content can be used, such as heterozygosity (H) and polymorphism information content (PIC). Here, we have determined heterozygosity scores and PIC values for all markers of the rat genetic linkage map, and we evaluate the predictability of the heterozygosity and the PIC values. Correlation analysis between the nine inbred strains reported for the rat map and ten test strains yielded r=0.42 and r=0.44 for heterozygosity and PIC values, respectively. While the correlation of the indices between the two groups of animals is low, these indices do provide a means of predicting whether a genetic marker will be informative in strains where allele sizes are not known.     

Characterization of strain specific typing antisera for genetic monitoring of inbred strains of rats

Strain-specific typing antisera (SSTA) were prepared for six inbred strains of rats by using a pooled immunization protocol. The SSTA were used in both a haemagglutination assay and a complement dependent microcytotoxicity assay to compare the usefulness of the two test systems. Both assays were simple, reliable and repeatable, and each system had distinct advantages and disadvantages. The haemagglutination assay was faster and required less specialized equipment than the microcytotoxicity assay. On the other hand, interpretation of results in the microcytotoxicity assay was easier and more objective. It was concluded that SSTA could be used with the microcytotoxicity assay and/or the haemagglutination assay to provide a simple and effective genetic monitoring method for inbred strain of rats.     

PCR-based microsatellite analysis for differentiation and genetic monitoring of nine inbred SENCAR mouse strains

Sixteen DNA microsatellites or simple sequence length polymorphisms (SSLPs), generated by polymerase chain reaction (PCR) were selected for use in the genetic quality control of the nine inbred SENCAR strains currently available. The SENCAR strains constitute a powerful tool for mechanistic studies of multi-stage skin carcinogenesis, as well as for studies to understand the underlying genetic basis of resistance to tumour promotion and progression. SSLP analysis is a fast and economical way for detecting genetic contamination (unexpected outcrosses) among these closely-related albino strains, where standard immunological and biochemical markers have been shown to be insufficient.     

Blood pressure, heart rate and motor activity in 6 inbred rat strains and wild rats (Rattus norvegicus): a comparative study.

Inbreeding for many generations under optimal environmental conditions may have favoured the survival of alleles for blood pressure increase in phenotypically normotensive rat strains. To prove this hypothesis we measured telemetrically systolic (SBP) and diastolic blood pressure (DBP), heart rate (HR) and motor activity (MA) in 6 inbred rat strains (BB, BN, LEW, DA, F344, WKY) and wild rats most probably possessing all of the alleles for normotension. For the first time it is shown that systolic blood pressure can significantly differ between normotensive inbred rat strains and that most probably some inbred rat strains will be characterised by a systolic blood pressure found in their progenitors, the wild rats. In addition, the typical night activity of rodents was not seen in 2 inbred rat strains. All findings together may be interpreted in the sense that most, if not all inbred rats strains have more or less disturbances in blood pressure, HR and/or MA and that there is most probably no "healthy" inbred rat strain available so that wild rats may be an alternative for crossing studies dissecting hypertension in particular and diseases in general.     

No relationship between sequence variation in protein coding regions of the Tas1r3 gene and saccharin preference in rats

Nearly all mammalian species like sweet-tasting foods and drinks, but there are differences in the degree of 'sweet tooth' both between species and among individuals of the same species. Some individual differences can be explained by genetic variability. Polymorphisms in a sweet taste receptor (Tas1r3) account for a large fraction of the differences in consumption of sweet solutions among inbred mouse strains. We wondered whether mice and rats share the same Tas1r3 alleles, and whether this gene might explain the large difference in saccharin preference among rats. We conducted three experiments to test this. We examined DNA sequence differences in the Tas1r3 gene among rats that differed in their consumption of saccharin in two-bottle choice tests. The animals tested were from an outbred strain (Sprague-Dawley; experiment 1), selectively bred to be high- or low-saccharin consumers (HiS and LoS; experiment 2), or from inbred strains with established differences in saccharin preference (FH/Wjd and ACI; experiment 3). Although there was considerable variation in saccharin preference among the rats there was no variation in the protein-coding regions of the Tas1r3 gene. DNA variants in intronic regions were detected in 1 (of 12) outbred rat with lower-than-average saccharin preference and in the ACI inbred strain, which also has a lower saccharin preference than the FH/Wjd inbred partner strain. Possible effects of these intronic nucleotide variants on Tas1r3 gene expression or the presence of T1R3 protein in taste papillae were evaluated in the ACI and FH/Wjd strains. Based upon the results of these studies, we conclude that polymorphisms in the protein-coding regions of the sweet receptor gene Tas1r3 are uncommon and do not account for individual differences in saccharin preference for these strains of rats. DNA variants in intron 4 and 5 are more common but appear to be innocuous.     

Respiratory responses to leukotrienes and biogenic amines in normal and hyperreactive rats

The effects of leukotriene D4, serotonin, and methacholine were studied on respiratory smooth muscle in vitro and respiratory responses in vivo in three strains of rats. These were an inbred strain of hyperresponsive rats, Sprague Dawley rats, and Fischer rats. Trachea from inbred rats responded in vitro to serotonin and methacholine but not to leukotrienes or histamine. Parenchyma from inbred rats responded to serotonin, methacholine, and leukotrienes. In vivo respiratory responses in inbred rats were observed after aerosol administration of histamine and serotonin, methacholine, and leukotriene D4. When these in vitro and in vivo experiments were repeated in Sprague Dawley and Fischer rats, a clear correlation was observed between the responses of strains of rats to aerosolized antigen and responses to spasmogenic mediators. It is concluded that inbred rats have a nonspecific bronchial hyperreactivity that contributes to their sensitivity to aerosolized antigen and that they may be a useful model for human asthmatic conditions.     

Blood pressure in rats: a comparison of a multifactorial experimental design to measurements in an outbred stock

Systolic blood pressure was measured in males of 8 inbred strains and 1 outbred stock of rats 5 times over a period of 20 min on 5 consecutive days. The strain means ranged between 107.9 mmHg and 149.3 mmHg. The estimated variance between strains (V = 248.7 mmHg) was about 5 times higher than the variance within strains (V = 54.3 mmHg). The intraindividual variance within strains was relatively constant (V = 24.0-37.6 mmHg), while the interindividual variance varied to a great extent (V = 4.5-44.5 mmHg) from strain to strain. The outbred stock showed values of blood pressure and components of variance similar to those of a single inbred strain. Thus, by investigation of a battery of 8 inbred strains in a multifactorial experimental design a greater phenotypic variability due to genetic strain differences is achieved than by measurements in a single outbred stock.     

Inconsistent susceptibility to autoimmunity in inbred LEW rats is due to genetic crossbreeding involving segregation of the arthritis-regulating gene Ncf1

We recently identified a single-nucleotide polymorphism in the Ncf1 gene, a component of the NADPH oxidase complex, to be the cause of one of the strongest identified loci for arthritis severity in rats. This polymorphism was found to be naturally occurring in a collection of inbred rat strains as well as in wild rats. Among the inbred strains we found that different LEW substrains (LEW/Ztm and LEW/Mol), originating from different breeders, showed an allelic discrepancy in Ncf1, suggesting an impact on arthritis susceptibility between these substrains. In fact, the LEW/Mol strain was completely resistant to pristane-induced arthritis, in contrast to the LEW/Ztm strain, which was susceptible. Moreover, the LEW/Mol strain had higher production of radical oxygen species in peripheral blood leukocytes, a phenomenon most likely regulated by the polymorphisms in the Ncf1 gene. However, the phenotypic difference between LEW/Mol and LEW/Ztm is most likely a combination of several genes, of which Ncf1 is suggested to be the major regulating gene. This has also been confirmed by previous linkage analyses involving the LEW/Ztm strain which shows that a QTL on chromosome 12, most likely caused by polymorphism of Ncf1, is the major regulatory gene but that other loci are contributing. That more genes are likely to contribute was shown by a complete genome comparison of the LEW/Ztm and the LEW/Mol rat strains that uncovered an introduction of approximately 37% non-LEW genome into the LEW/Mol strain, which probably was caused by past crossbreeding. Therefore, the LEW/Mol should be regarded as a recombinant inbred strain.     

近交系剑尾鱼的遗传生化标记研究

目的通过研究对RR-B、RW-H、BY-F三个近交系和非选育剑尾鱼的研究比较,建立近交系剑尾鱼的遗传生化标记检测技术。方法依照国标GB／T14927.1-2008的遗传操作规程优化实验条件,对三个近交品系及非选育群剑尾鱼的不同组织的6个遗传生化位点进行研究,以得到其遗传生化图谱。结果在6个生化位点中,同一品系剑尾鱼同工酶存在组织特异性,多数同工酶在肝中活性较强。同一生化位点在不同品系间存在差异。RR-B系在葡萄糖磷酸异构酶（Gpi）、6-磷酸葡萄糖脱氢酶（Gpd）位点表现出特异性条带,RW-H系在过氧化氢酶（Ce）位点表现出特异性条带。同一生化位点在各品系内表现较为一致,而在非选育剑尾鱼中在上述三个生化位点表现出多态性。在酯酶（ES）、碱性磷酸酶（AKP）、乳酸脱氢酶（LDH）位点,各品系谱带不易区分其差异。结论建立了剑尾鱼近交系生化标记检测技术,可望用于近交系剑尾鱼的遗传质量监测。     

A comprehensive mouse IBD database for the efficient localization of quantitative trait loci

Traditional fine-mapping approaches in mouse genetics that go from a linkage region to a candidate gene are very costly and time consuming. Shared ancestry regions, along with the combination of genetics and genomics approaches, provide a powerful tool to shorten the time and effort required to identify a causative gene. In this article we present a novel methodology that predicts IBD (identical by descent) regions between pairs of inbred strains using single nucleotide polymorphism (SNP) maps. We have validated this approach by comparing the IBD regions, estimated using different algorithms, to the results derived using the sequence information in the strains present in the Celera Mouse Database. We showed that based on the current publicly available SNP genotypes, large IBD regions (>1 Mb) can be identified successfully. By assembling a list of 21,514 SNPs in 61 common inbred strains, we inferred IBD regions between all pairs of strains and confirmed, for the first time, that existing quantitative trait genes (QTG) and susceptibility genes all lie outside of IBD regions. We also illustrated how knowledge of IBD structures can be applied to strain selection for future crosses. We have made our results available for data mining and download through a public website ( ). Electronic Supplementary Material Electronic Supplementary material is available for this article at and accessible for authorised users.     

Binding characteristics of atrial natriuretic factor and the production of cyclic GMP in kidneys of Dahl salt-sensitive and salt-resistant rats

The binding of atrial natriuretic factor (ANF) was studied in kidney membranes of inbred salt-sensitive (S) and inbred salt-resistant (R) rats on high or low salt diet. Important differences between strains were seen in the rate of dissociation of ANF from its renal receptor(s) and this was dependent on salt (NaCl) intake. On low salt diet ANF dissociation rates were similar between strains. R rats responded to high salt diet with a decrease in the rate of ANF dissociation from its renal receptor, but ANF dissociation in S rats was not altered by dietary salt. Receptor density was similar between strains. Basal cGMP production was slightly higher for renal membranes of S rats, but ANF stimulation of cGMP production was similar between strains and was not influenced by salt intake in either strain. Since strain-related salt-induced changes in ANF-receptor binding kinetics were not reflected in any strain-related salt-induced changes in ANF stimulated cGMP production, it is tentatively concluded that the ANF receptor likely to be different between S and R strains is the ANF receptor not linked to cGMP production.     

Establishment and characteristics of three analbuminemic congenic strains of rats

We have established three analbuminemic congenic strains of rats (ACI-alb, F344-alb, and SHR-alb) by repeated backcrossing with a progeny test or intercrossing. Some coat color and biochemical marker genes of each congenic strain agreed with those of the background inbred strain of rats, except for the alb gene locus. These established congenic strains were maintained by cross-intercrossing. Body weights, organ weights and serum lipid concentrations of each strain were measured up to 30 weeks of age. Body weights of ACI-alb congenic strains (alb/alb and alb/+) were similar to those of the original ACI(+/+) strain, but those of F344-alb and SHR-alb were heavier in the order of +/+, alb/+ and alb/alb. The liver and adrenal weights of all strains were higher in the order of alb/alb, alb/+ and +/+. Serum lipid concentrations were also higher in the same order. These three analbuminemic congenic strains originating from different inbred strains should be useful in studies of carcinogenesis and genetically modified mechanisms of albumin functions.     

Unique genetic variation revealed by a microsatellite polymorphism survey in ten wild-derived inbred strains

Here we report on a genome polymorphism survey using 254 microsatellite markers in ten recently wild-derived inbred strains. Allele size analysis showed that the rate of polymorphism of these wild-derived mouse strains when compared with any of the common laboratory strains is on average 79.8%. We found 632 wild-derived alleles that were not present in the common laboratory strains, representing a 61% increase over the genetic variation observed in the laboratory strains. We also found that on average 14.5% of the microsatellite alleles of any given wild-derived inbred strain were unique. Our results indicate that the recently wild-derived mouse strains represent repositories of unique naturally occurring genetic variability and may prove invaluable for the study of complex phenotypes and in the construction of new mouse models of human disease.     

Differences in response to anaesthetics and analgesics between inbred rat strains

Differences in response to analgesic and anaesthetic drugs can partly be attributed to variations in the genetic background of experimental animals. This study was carried out to determine differences in the response of inbred rat strains to a selection of analgesics and drugs used in anaesthetic protocols. A cross between the most contrasting strains can then be phenotyped in future studies in order to localize quantitative trait loci (QTLs) involved in analgesic/anaesthetic drug sensitivity. Eight inbred strains (n = 6 rats/strain) were selected for the study: the pigmented ACI, BN and COP strains and the albino F344, LEW, SHR, WAG and WKY strains. Each rat was injected intravenously with two analgesics (buprenorphine 0.05 mg/kg and nalbuphine 1 mg/kg) and three drugs used in anaesthetic protocols (propofol 25 mg/kg, medetomidine 50 microg/kg and ketamine 10 mg/kg), respectively, using a crossover design. Analgesic responses were assessed using an analgesiometric procedure. The sleep time of the rat and, where applicable, the interval between injection and loss of righting reflex were used to determine the anaesthetic response. Six out of eight strains responded significantly different from each other to the analgesic effect of buprenorphine with the ACI strain as hyper-responder. The tail withdrawal latency at 55 degrees C of the F344 and WKY rats using buprenorphine was not significantly different from baseline tail withdrawal latencies. In this study, all strains were non-responsive to the analgesic effects of nalbuphine. The response to all three drugs used in anaesthetic protocols differed significantly among the strains. The F344 and BN strains were relatively resistant to the sedative effects of medetomidine. Use of ketamine was abandoned in the ACI and BN strains when the first two animals of both strains died soon after induction. With all three drugs the sleep time of albino rats was significantly longer compared with that of the pigmented ones. We conclude that the results from this study can be used in future studies where QTLs for the sensitivity to anaesthetic/analgesic drugs are localized.     

Ontogenesis and independent genetic control of the rat adenylate kinase isozymes (EC 2.7.4.3.)

The level of activity of cytoplasmic isozyme II of adenylate kinase (EC 2.7.4.3) appears to be genetically controlled in the rat (Rattus norvegicus). Adult animals of the Okamoto inbred strain exhibit a ninefold higher erythrocytic activity than the rats of the dilute agouti inbred strain. This difference seems to be due to two codominant autosomal alleles at a same locus. The study of the ontogeny of that enzyme in muscle in the two strains shows that the wellknown postnatal activity increase of that isozyme is reduced in the low activity (dilute agouti) strain. However, the mitochondrial isozyme III activity is not similarly regulated as no difference between the two strains has been observed.     

Rat interstrain antibody response and crossidiotypic specificity

Interstrain analysis of the humoral response of rats to streptococcal group A carbohydrate (SACHO) 1, employing seven inbred strains representing six histocompatibility haplotypes at the Ag-B locus, suggests that the immune response genes to SACHO are not linked to the major rat histocompatibility locus. The low-precipitin response of all seven inbred rat strains was similar to the precipitin response of F₇ Sprague-Dawley rats selectively bred for a low-precipitin response to SACHO. Although strain differences were not apparent in the magnitude of the precipitin response to SACHO, the qualitative expression of anti-SACHO antibodies with restricted heterogeneity was more frequently observed in the August strain of rats than in the six other inbred strains examined. Cross-idiotypic specificity was demonstrated for anti-SACHO antisera obtained from nine inbred rat strains. The observations on idiotypy favor the importance of germ-line genes coding for rat antibody variable region determinants in response to SACHO.In this paper, the following abbreviations are used SACHO streptococcal group A carbohydrate - Aug August 2887 - W/Fu Wistar Furth - M520 Marshall 520 - Cop Copenhagen - F344 Fisher 344 - Buf Buffalo/Cr - BN Brown Norway - GASV group A streptococcal vaccine - DEAE diethylaminoethyl-cellulose - RIA radioimmunoassay     

Identification of a genetic contamination in a commercial mouse strain using two panels of polymorphic markers

Rapid detection of genetic contamination is critical in mouse studies involving inbred strains. During a Quantitative Trait Locus (QTL) study using simple sequence length polymorphism (SSLP) markers, we noticed heterozygosity at some loci of a commercially available inbred C57BL/6N mouse strain, suggesting a contamination by another mouse strain. A panel of 100 single-nucleotide polymorphism (SNP) markers was used to confirm and specify the genetic contamination suspected. Retrospective analyses demonstrated that the contamination took place as early as autumn 2003 and has persisted ever since at a fairly constant level. Contaminating alleles most probably originated from a DBA strain. Our data demonstrate the suitability of SNP markers for rapid detection and identification of the source of genetic contamination. Further, our results show the importance of a state-of-the-art genetic monitoring of the authenticity of murine inbred strains.     

Strain differences in kidney copper concentrations of male rats

The copper concentrations of the kidneys of male rats of six inbred (BN, F344, LEW, SHR, WAG/Cpb, and WAG/Rij) and one random-bred Wistar strain were determined. In inbred rats the mean concentration varied between strains and ranged from 7.10 μg/g for F 344 to 23.48 μg/g for WAG/Cpb. The calculated coefficient of genetic determination (g²) was 0.88. A remarkable discrepancy was found between the two WAG inbred strains; the WAG/Cpb had a 2.5 times higher kidney Cu concentration than the WAG/Rij. Kidney Cu concentrations of random-bred rats varied considerably; the coefficient of variation of the means was 28 and 34% in two samples taken with a 1-yr interval, respectively, indicating inhomogeneity within the population. The results indicate that the individual differences in kidney Cu concentration have a genetic basis.     

Efficient collection and cryopreservation of embryos in F344 strain inbred rats

In rats, it is now possible to produce genetically engineered strains, not only as transgenic animals but also using gene knockout techniques. Reproductive technologies have been used as indispensable tools to produce and maintain these novel valuable strains. Although studies for collecting and cryopreserving embryos have been reported using outbred rats, efficient methods have not been established in inbred strains. The F344 inbred strain is important in rat breeding and has been used for the production of transgenic/knockout strains and for genome sequencing. Here we studied the optimal conditions for oocyte collection by induction of superovulation, and the development of embryos after cryopreservation in F344 rats. The response to pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG) was examined by injection of 150 IU/kg PMSG + 75 IU/kg hCG or 300 IU/kg PMSG + 300 IU/kg hCG. Superovulation was achieved at high efficiency by an injection of 150 IU/kg PMSG + 75 IU/kg hCG. Furthermore, superovulation in this strain showed similar high response as Wistar rats. Of 2-cell embryos cryopreserved by vitrification in a solution containing 10% propylene glycol, 30% ethylene glycol, 20% Percoll and 0.3 M sucrose, more than 90% survived after warming and 32% developed to offspring. However, the freezability of pronuclear stage embryos was extremely low. This study demonstrated that sufficient unfertilized oocytes and embryos can be collected from F344 rats by the induction of superovulation with 150 IU/kg PMSG + 75 IU/kg hCG. Furthermore, cryopreservation of 2-cell embryos using this vitrification protocol can now be applied to maintaining valuable rat strains derived from the F344 inbred strain as genetic resources.