近交系HFJ大鼠的培育及其部分表型观察

目的培育高繁殖力近交系HFJ大鼠并观察其部分表型特征。方法以一对Wistar大鼠为基代,通过全同胞近亲交配方式,采用选优法培育高繁殖力近交系HFJ大鼠。采用生化标记法、皮肤移植实验进行遗传质量检测;观察比较其部分表型特征。结果HFJ种群符合近交系标准;其窝产仔数、离乳率、胎次间隔显著高于Wistar大鼠;HFJ大鼠12周龄后生长缓慢,体重低于同龄Wistar大鼠;HFJ大鼠部分血液常规指标及血液生化指标与Wistar大鼠有显著差异。结论HFJ大鼠繁殖力强,是具有独特生物学特性的近交系大鼠。     

雄性不育大鼠近交系MIJ的建立及其遗传特征观察

以发现的雄性不育大鼠的正常表型同胞鼠为种鼠,通过全同胞近亲交配方式,采用选优法成功培育出自发雄性不育大鼠近交系MIJ.同系异体皮肤移植验证其遗传纯合度,观察其表型特征,并通过遗传测交试验测定雄性不育性状的遗传方式.结果表明.MIJ种群符合近交系标准;雄性不育大鼠呈睾丸下降延迟、睾丸及附睾发育迟缓、精子数量少及精子生成障碍;近交系内其他个体表型正常.不育性状呈隐性遗传方式,由常染色体上单一隐性基因控制.该雄性不育大鼠可作为人类男性不育研究的动物模型.     

实验大鼠的生化多态性及在遗传监测中的应用

利用生化标记基因(biochemical markergene)对近交系小鼠的遗传纯度进行检测,目前已成为各国实验动物遗传监测的主要方法。随着大鼠在生物医学研究中应用的日益广泛,目前世界上育成的近交系大鼠数目已逾百个,我国近年来引进及自己育成的至少也有十几个品系。为了建立近交系大鼠遗传质量监测的生化方法,根据近年来国际上大鼠生化遗传学方面的进展,我们利用同工酶电泳方法,对Wistar等两个远交封闭群和ACI等两个近交系大鼠在九个生化位点的遗传多态性进行了检查,现报告如下:     

近交系DA大鼠遗传学质量

目的通过鼠尾皮肤循环移植和生化标记法检测DA大鼠的生化标记基因,为动物实验的研究提供丰富的动物基因库。方法采用鼠尾皮肤循环移植法观察自体与异体皮片成活率,采用蛋白质与同工酶醋酸纤膜电泳法,对试验DA大鼠进行碱性磷酸酶等11个生化标记基因位点进行确定。结果DA大鼠自体与异体移植的皮片在100 d的观察期间全部成活,DA大鼠11个生化标记基因位点均为纯合的。结论DA大鼠生化位点的确定,奠定了DA大鼠的生化位点遗传概貌的理论基础,为进一步研究DA大鼠提供遗传学资料。     

黑龙江省实验大鼠遗传学概貌分析

目的对送检的黑龙江省生产的实验大鼠遗传概貌进行分析。方法参照国家标准《实验动物近交系小鼠、大鼠生化标记检测方法》GB/T14927.1-2001,应用乙酸纤维素板,利用Akp1、Es1、Es3、Es4、Es6、Es8、Es9和Es10等8种同工酶位点,对来自编号分别为2011、2014、3026、8028和8029的5个单位的SD、Wistar、DA、PVG等4个品系的25只实验大鼠,进行生化标记位点的检测。结果除单位2014的SD大鼠在Es3存在a和b两种带型,8028和8029未检测Es10、2014和3026未检测Es6,8,9,其余各单位的大鼠在8个位点都表现出相同的带型。结论送检的黑龙江省生产的SD和Wistar大鼠符合封闭群遗传学概貌;DA和PVG大鼠样品间带型一致。     

近交系MIJ和HFJ大鼠生化标记基因的测定

目的 观察MIJ和HFJ大鼠的基因纯合度和遗传稳定性.方法 MIJ大鼠7只,取自F22代基础群中3对种鼠和F22代雄性生殖缺陷鼠1只.HFJ大鼠6只,取自HFJ大鼠F25代基础群中的3对种鼠.按照中华人民共和国国家标准GB/T14927.1-2001实验动物近交系小鼠、大鼠生化标记检测方法测定.结果　MIJ和HFJ近交...     

雌激素和植物雌激素对大鼠杏仁核多巴胺能系统的调节

用快速周期伏安法(fast cyclic voltammetry,FCV)测定了动情周期各期雌鼠、去卵巢(ovaricectomized,OVX)鼠和正常雄鼠的杏仁核(amygdala,Amy)多巴胺(dopamine,DA)释放,同时应用酪氨酸羟化酶(tyrosine hydrox-ylase,TH)免疫组化技术检测了以上各组大鼠腹侧背盖区(ventral tegmental area,VTA)的TH阳性神经元数目。并在此基础上,将植物雌激素——大豆异黄酮侧脑室注射,观察了其对各组大鼠Amy DA释放的作用。结果显示,雌鼠动情前期DA释放量最高,高于其余三期和OVX鼠;AmyDA释放和VTATH阳性神经元数目存在明显的性别差异,雌性高于雄性;大豆异黄酮可快速(5min内)增加雌鼠、OVX鼠的Amy DA释放,提示大鼠内源性雌激素水平差异对中脑边缘系统DA能神经元存在调节作用,大豆异黄酮可在中枢发挥类雌激素作用,调节杏仁核DA能神经递质系统功能。     

微卫星DNA监控大鼠近交系的培育

采用微卫星DNA技术来监控大鼠仔代基因状况,选择性地进行交配繁殖,使基因快速纯合,缩短培育新的近交系动物周期。利用PCR扩增30个微卫星DNA位点对封闭群SD和Wistar大鼠交配繁殖的仔代鼠进行微卫星DNA多态性分析,仔代中与母代SD大鼠相似系数高的与中的进行定向交配繁殖。F2代大鼠均为杂合多态的位点,没有纯合位点;到F9代时基因纯合位点达27个,纯合基因位点率为90%。每代相似系数具有不断上升的趋势,上升率为6-20%。采用皮肤移植方法验证了F9代大鼠间无排斥。建立了一种新的快速培育近交系动物的方法。     

大鼠内细胞团和胎儿神经干细胞构建嵌合体的潜力

嵌合体大鼠是研究人类疾病的重要动物模犁.用囊胚注射法研究了大鼠内细胞团(ICM)和胎儿神经干细胞(FNS)构建嵌合体的潜力.结果发现来自黑色(DA)大鼠第5天(D5)和第6天(D6)囊胚的ICM细胞注入D5 Sprague-Dawley(SD)大鼠囊胚后得到3只嵌合体大鼠:D5 SD大鼠ICM细胞注射入D5 DA囊胚后得到4只嵌合体大鼠:而体外培养的DA或SD人鼠ICM细胞注射后均未能获得嵌合体大鼠.本研究用大鼠胎儿神经干细胞(rFNS)和LacZ转染的rFNS构建嵌介体,未能获得嵌合体人鼠:但在LacZ转染的SD rFNS注射到DA大鼠囊胚后发育来的41只胎儿中,有2只胎儿其组织切片中发现少量LacZ阳性细胞.结果表明DA和SD大鼠ICM具有参与嵌合体发育的潜力,但ICM细胞经体外培养后构建嵌合体的潜力显著F降(P＜0.05);大鼠胎儿神经干细胞构建嵌合体的潜力较低,可能仅具有参与早期胚胎发育的潜力.     

SPF级近交系Wistar大鼠繁殖性能的观察

目的对近交系Wistar大鼠进行繁殖性能的测定。方法选取血缘扩大群共18对,90日龄开始按1♀＊1♂进行交配,统计其生长繁殖性能。结果第二、三、四胎的平均窝产仔数和断奶窝重比第一和第五胎高。第一胎仔鼠从出生第3天到第7天（增重9．42g）、第14天到第21天（13．98g）快速生长。母鼠怀孕期、哺乳期体重、饲料和水的日消耗量有明显的差异,母鼠哺乳期饲料和水的日消耗量均比怀孕期高,母鼠怀孕期体重明显比哺乳期重,母鼠怀孕期体重后期比初期增加150g左右,曲线呈上升趋势。结论本群Wistar近交系大鼠的生长繁殖符合近交系大鼠的生长繁殖规律。     

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.     

Elevated atrial natriuretic polypeptide in plasma of hypertensive Dahl salt-sensitive rats

The relationship between circulating atrial natriuretic polypeptide (ANP) and blood pressure was studied in inbred Dahl salt-sensitive (S) and inbred Dahl salt-resistant (R) rats. Two month old S and R rats raised on normal rat chow had only small differences in blood pressure and no difference in plasma ANP levels. In contrast, when 6-month-old rats also raised on normal chow were studied, S had markedly elevated blood pressure and a 4 fold increase in plasma ANP compared to R. Similar strain differences in blood pressure and plasma ANP could be induced in young rats by feeding them diets high in salt. In six week old S and R rats which had been fed high salt diet for 3 weeks the S rats showed higher blood pressure and plasma ANP than R rats. The high plasma ANP levels seen in the hypertensive S rats were interpreted to be a response to hypertension and not a cause of hypertension. There was no qualitative strain difference in the plasma ANP molecule as assessed by reverse phase high pressure liquid chromatography.     

Comparison of male reproductive parameters in three rat strains: Dark Agouti, Sprague-Dawley and Wistar

The choice of experimental animal can have a large impact on experimental results, an example is the anecdotal evidence suggesting that Dark Agouti (DA) rats have a lower reproductive capacity than other rat strains. In this paper we report on an investigation into male reproductive characteristics in three rat strains--Wistar, Sprague-Dawley (outbred strains) and DA (an inbred strain). Reproductive organ weights, blood testosterone levels and sperm counts were measured in mature age-matched male rats. DA animals had significantly smaller testis weights than the Sprague-Dawley and Wistar animals, and this did not appear to be related to the overall smaller body mass of the DAs. There were no differences between the three strains in testicular histology or sperm counts (per gram testis). Although there was also no significant difference in epididymal sperm count, the DA animals had a much greater variability in sperm count than the other strains. There were no differences in relative (to body weight) epididymal, seminal vesicle or ventral prostate weights or in the blood testosterone levels. These results suggest that differences in reproductive capacity in DAs are neither the result of morphological differences in the reproductive organs nor in circulating testosterone levels. Sperm production appears to be normal but the lowered testicular weight and variability in epididymal sperm counts suggests that there are other factors in the testicular or epididymal environment which alter male reproductive function.     

近交系MIJ和HFJ大鼠部分生理数据测定和分析

目的测定近交系大鼠MIJ、HFJ和封闭群Wistar大鼠的脏器系数、体温、呼吸频率、肠管长度,观察两个近交系大鼠的生理表型。方法 采用常规方法对大鼠脏器系数、体温、呼吸频率及肠管长度进行测定,并对HFJ、MIJ、Wistar大鼠三者间进行比较。结果①体重:HFJ、MIJ、Wistar大鼠同性别间比较差异无显著性。②脏器系数:HFJ与Wistar大鼠雄性间心脏、肺,雌性间子宫、肝;MIJ与Wistar大鼠雄性间肺、脾,雌性间脑、脾,差异均有显著性。HFJ与MIJ大鼠雄性间脑,雌性间脑和脾差异有显著性。HFJ大鼠不同性别间肝、脑、眼球差异有显著性。MIJ大鼠不同性别间,脑、心脏、肾、肺、脾和眼球差异均有显著性。③体温:HFJ雌性大鼠明显高于Wistar雌性,雄性间差异无显著性。HFJ大鼠雌性高于雄性,差异有显著性。④呼吸频率:HFJ雌性大鼠低于同性Wistar大鼠,MIJ大鼠雌性和雄性均高于同性别Wistar大鼠,差异有显著性。⑤肠管长度:HFJ与Wistar同性别间比较,肠管总长和小肠差异有显著性。MIJ与Wistar大鼠雄性间肠管总长、大肠、小肠、盲肠差异均有显著性,雌性间肠管总长、小肠、盲肠差异有显著性。HFJ与MIJ大鼠同性别间差异均无显著性,不同性别的HFJ和MIJ的肠管总长、大肠和小肠差异有显著性。结论 MIJ和HFJ近交系大鼠的脏器系数、体温、呼吸频率、肠管长度都各有其独特的生理概貌。     

Transfusion induces blood donor-specific suppressor cells

Transfusion with blood from the organ donor before transplantation can prolong the survival of renal allografts in the rat. To determine if the beneficial effect of preoperative blood transfusion was due to the generation of donor-specific suppressor cells, in vivo and in vitro adoptive transfer experiments were performed. Lymphoid cells were harvested from transfused and untreated rats. These cells were then either (1) transferred to lightly irradiated (200 R) syngeneic hosts which were subsequently challenged with a kidney allograft (in vivo assay) or (2) titrated as regulator cells into naive unidirectional MLC such that the regulator and responder populations were syngeneic. In the LEW-RT1 to DA-RT1av1 strain combination, the adoptive transfer of thoracic duct lymph (TDL) or lymph node (LN) cells (5 x 10(7) to 7.5 x 10(7) cells) from DA animals transfused with LEW blood, 7 days previously into syngeneic (DA), lightly irradiated (200 R) hosts resulted in the indefinite survival of LEW kidney allografts. The phenomenon was blood donor-specific and dose-dependent. In contrast the adoptive transfer of spleen cells (10(7) to 10(8] from blood transfused hosts 7 days after transfusion had no effect on renal allograft survival. In vitro the addition of LN or TDL regulator cells, harvested from DA rats transfused with LEW blood, to a unidirectional MLC (DA responders, LEW stimulators) resulted in a significant depression of the proliferative response when compared with the proliferation of these same cells without the addition of these regulator cells or with the addition of LN or TDL regulator cells from a DA rat transfused with third party (PVG-RT1c) blood. The depression of the proliferative response observed in vitro, was blood donor specific. When LN or TDL regulator cells from a DA rat transfused with PVG-RT1c blood were added to a unidirectional MLC between DA responders and PVG stimulators, a significant depression in the proliferative response was observed. These in vitro findings were confirmed in two other strain combinations (LEW-PVG, and DA-PVG). Thus a single blood transfusion results in the induction of donor-specific suppressor cells detectable both in vivo and in vitro 7 days after transfusion in some but not all lymphoid compartments.     

The effect of inbreeding on potato cyst-nematode, Heterodera rostochiensis

Two populations, Duddingston and Feltwell, of potato cyst-nematode were inbred for seven and six generations respectively. The Duddingston population maintained a high fecundity in some lines for three generations, but in subsequent generations the fecundity as measured by cyst production declined in spite of selection for high fecundity. By selecting for fecundity, some lines of the Feltwell population still produced many cysts after five generations of inbreeding. In the Duddingston population it was possible to increase the number of cysts produced by an inbred line of poor fecundity by using paired cysts plus selection for fecundity. A similar change may have been obtained for unprolific lines of the Feltwell population. Selection for production of few cysts quickly produced lines with poor fecundity. One cause of poor fecundity was the small number of larvae in cysts used for inoculations. Yellow eggs were found in large numbers in some cysts but these were not a cause of loss of fecundity following repeated inbreeding.     

Qualitative and quantitative variability in different classes of proteins: Comparison of mouse and rat

Summary Proteins of membranes and cytosols were extracted from the livers and brains of mice (inbred strain DBA/6J) and rats (inbred strain DA/Han) and separated by two-dimensional electrophoresis (2-DE). The 2-DE patterns were compared with regard to qualitative (spot position) and quantitative (spot intensity) characteristics of the proteins of these two species.The following results were obtained: (1) Brain had more (higher percentage) conservative proteins (proteins found in both mice and rats) than liver; (2) plasma membranes had more conservative proteins than the cytosols; (3) organ-unspecific proteins contained more conservative proteins than relatively organ-specific proteins; (4) the pattern of distribution of genetic variability among different classes of proteins represented by findings 1–3 was the same for the qualitative and quantative characteristics of the proteins; and (5) some observations indicated that quantitative variability occurred more frequently among proteins than did qualitative variability. Our conclusion is that regulatory sequences in the DNA (regulatory genes) are subjected to functional constraints that differ in strength among different classes of proteins by the same ratios as the constraints acting on the structural genes. The overall effect of the selective pressure is, however, less stringent for regulatory genes than for structural genes.The results obtained here by comparing two different species are very similar to previous results we obtained by studying different subspecies (inbred strains of the mouse). From this finding arises a new concept: the study of molecular evolution on the basis of different classes of proteins.Our results were compared with data from the literature that were obtained in part from studies on cultured cells. The comparison suggested that cultured cells have lost their tissue-specific proteins, and so generate predominantly extremely conservative proteins.     

Increased catecholamine output in the hypertensive fawn-hooded rat

The total 24 hour urinary outputs of the catecholamines norepinephrine (NE), epinephrine (E), dopamine (DA) and the DA metabolite homovanillic acid (HVA) were measured in hypertensive fawn-hooded rats and compared to the ancestral strain of normotensive Wistar rats. The hypertensive fawn-hooded rats demonstrated significantly higher urinary outputs of the catecholamines NE and DA, and of the DA metabolite HVA. Following treatment with the antihypertensive, debrisoquin sulfate, the blood pressure of the fawn-hooded rats decreased until it approached the levels observed in normotensive Wistar rats. By inhibiting sympathetic nervous activity and monoamine oxidase, the debrisoquin treatment significantly decreased the output of DA, NE and HVA but not E. The data suggest the fawn-hooded rat is a model of neurogenic hypertension which is characterized by an increased sympathetic output.     

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.