DNA指纹技术在近交系动物遗传检测中的研究

采用生物素标记的(GGAT)4寡核苷酸探针对DBA1、DBA2两种近交系小鼠及DBA2×DBA1 F1代小鼠进行了DNA指纹图分析,并与常规生化位点标记分析法进行了比较.结果显示,DNA指纹图具有良好的多态性,不仅可以分辨生化位点标记分析法能够区分的不同品系的近交系动物,而且也能够分辨生化位点标记分析法不能区分的不同品系的近交系动物.研究还表明,用同一方法重复同一基因组DNA的指纹图时,获得相同的实验结果.因此,DNA指纹图法不仅比传统的生化位点检测分析法有更好的分辨力,也具有良好的稳定性.     

用寡核苷酸探针对近交系小鼠DNA指纹图谱的分析

应用DNA指纹技术，用非放射性标记的寡核苷酸探针(GGAT)。对3个清洁级近交小鼠品系C57、DBA／2、BALB／c进行检测，分析其DNA指纹图谱。结果显示，不同品系近交系小鼠的DNA指纹图谱有明显差异，而品系内小鼠之间的DNA指纹图谱基本一致。证明DNA指纹技术能够较好地检测出近交系小鼠的基因纯合性，反映其遗传质量，可以应用于对近交系小鼠的遗传质量监测。     

DNA指纹图与生化指标分析对近交系小鼠遗传检测的比较

采用JL-02多位点探针对来自北京和西安地区的5个BALB/c群、2个BALB/c-nu/nu群、4个C57群、1个CBA/N群和1个DBA/2群近交系小鼠进行了DNA指纹图分析,并与常规生化标记分析法进行了比较.结果显示,DNA指纹图的图带教均为17～22条,具有良好的多态性.生化标记分析中Hbb位点显示异常的BALB/c及BALB/c-nu/nu小鼠与其同群体正常小鼠的DNA指纹图有较大差异,2个体之间的相似系数(F)及共有带率(X)均在0.8以下,完全相同DNA指纹图的概率(P)均在1.3×10-2以下;生化标记分析未见异常的群体内,DNA指纹图基本一致,P＞2.2×10-1.DNA指纹图显示,不同单位的同一品系间存在一定差异,其F及X均在0.8以下,P＜1.1×10-3.不同品系间DNA指纹图的F及X相差较大,均在0.4以下,P=2.7×10-10.BALB/c群与BALB/c-nu/nu群间DNA指纹图的F和X在0.65以下,P=3.8×10-6.同一动物的基因组DNA,经不同次实验所得出的DNA指纹图基本一致.2种方法比较表明,DNA指纹图在动物遗传检测中比生化标记分析有较大的优势,它不但能确切地反映生化标记分析显示的异常动物的遗传变化,而且还检出了生化标记分析未能检出的动物遗传变异,因此更加灵敏.DNA指纹图能反映出动物个体间、群体间及品系间的变异程度、亲缘关系及遗传距离,这是生化标记分析无法比拟的.     

近交系大鼠DNA指纹图稳定性的研究

为建立ＤＮＡ指纹技术在近交系大鼠遗传监测中的方法，采用ＤＮＡ指纹图对国内已知的７个品系近交系大鼠群体进行了分析，并对相同ＤＮＡ进行了多次ＤＮＡ指纹图重复实验，其结果表明：不同品系之间ＤＮＡ指纹图差异较大，其平均图带数为（１６．３６０±２．１７８），共有带率为（０．０６１±０．００８），相似系数为（０．０６２±０．００８），相同ＤＮＡ指纹图概率为３．６９１×１０－２３。相同ＤＮＡ不同次制作的ＤＮＡ指纹图谱基本一致（Ｐ＞０．０５）。同一个体不同组织的ＤＮＡ指纹图也基本相同，从而证实了该方法具有高度的稳定性和可重复性。     

近交系大鼠DNA指纹图与微卫星DNA比较分析

为了建立一种对近交系大鼠遗传物质进行精确可靠、快速简便的监测方法，利用DNA指纹技术对国内6个品系8个近交系大鼠群体进行了DNA多态性的分析，并与PCR扩增微卫星DNA技术进行了比较。其结束显示：(1)不同品系之间DNA指纹图差异较大，同一群体不同个体间DNA指纹图带的相似系数和共有带率除SHR（哈)和WKY(哈)小于0．7外，其他均大于0．9。不同地区同一SHR间和WKY间DNA指纹图也存在差异，相同DNA不同次制作的DNA指纹图谱基本一致。(2)不同品系个体间微卫星DNA具有显著多态性；同一群体不同个体之间除SHR(哈)的SMST位点和WKY(哈)的AGT位点出现一定的差异外，其他均没有差异。DNA指纹图能更精确可靠地反映出动物个体间的遗传背景，而微卫星DNA遗传监测方法比较简便快捷。     

近交系大鼠DNA指纹图与微卫星DNA比较分析

为了建立一种对近交系大鼠遗传物质进行精确可靠、快速简便的监测方法,利用DNA指纹技术对国内6个品系8个近交系大鼠群体进行了DNA多态性的分析,并与PCR扩增微卫星DNA技术进行了比较.其结果显示(1)不同品系之间DNA指纹图差异较大,同一群体不同个体间DNA指纹图带的相似系数和共有带率除SHR(哈)和WKY(哈)小于0.7外,其他均大于0.9.不同地区同一SHR间和WKY间DNA指纹图也存在差异,相同DNA不同次制作的DNA指纹图谱基本一致.(2)不同品系个体间微卫星DNA具有显著多态性;同一群体不同个体之间除SHR(哈)的SMST位点和WKY(哈)的AGT位点出现一定的差异外,其他均没有差异.DNA指纹图能更精确可靠地反映出动物个体间的遗传背景,而微卫星DNA遗传监测方法比较简便快捷.     

利用RAPD标记分析近交系小鼠的遗传多态性

采用随机扩增多态性DNA（RAPD）标记，分析了BALB／c、57BL／6、DBA／2、C3H／He近交系小鼠的遗传多态性。结果表明，上述小鼠表现出了各自不同的多态性RAPD标记；RAPD可作为近交系小鼠的分子标记， 在DNA水平区别4种近交系小鼠。     

微卫星DNA在近交系小鼠遗传监测中的应用

用7对引物对5种不同品系近交系小鼠的微卫星位点进行多态性分析。结果显示,不同品系及同品系不同个体近交系小鼠的扩增产物在7个微卫星位点上均出现一清晰条带,在不同品系小鼠之间筛选出4个（D3Mit22、D6Mitl92、D6Mit36、D6Mitl49）具有多态性的位点;同品系内不同个体之间没有多态性。结果表明,所检测的小鼠符合近交系要求,筛选出的4个微卫星位点可用于国内有关近交系小鼠的遗传背景监测。     

日粮核苷酸对机体炎症抗炎症平衡体系的影响

为探讨日粮核苷酸对小鼠炎症／抗炎症平衡体系的作用，用CpG DNA和脂多糖（LPS）刺激小鼠构建炎症反应模型，观察分别饲喂无核苷酸（NF）日粮和核苷酸（NT）日粮小鼠的炎性细胞因子IL-1、IFN-λ，、抗炎性细胞因子IL-10水平和小肠髓过氧化物酶（MPO）活性变化。结果显示，在刺激后第4h时，NT组小鼠的IL-1（P〈0．05）、IFN-λ，（P〈0．01）和小肠MPO（P〈0．01）明显低于NF组，IL-10（P〉0．05）高于NF组；刺激后第18h时，NT与NF组的IL-1（P〈0．01）、IFN-λ，（P〈0．01）、IL-10（P〉0．05）和MPO（P〈0．01）均较刺激后第4h有所降低，NT组的IL-1（P〉0．05）、IFN-λ，（P〈0．05）和小肠MPO（P〈0．05）仍低于NF组，IL-10（P〉0．05）仍高于NF组。表明，日粮核苷酸对CpG DNA或LPS所诱导的炎症反应有明显的抑制作用，有助于维持机体炎症／抗炎症平衡，保护机体免受炎症损伤。     

用牛的小卫星探针BM6.21A进行鸭的DNA指纹分析

用牛的小卫星探针ＢＭ６．２１Ａ对７个品系的北京鸭进行ＤＮＡ指纹分析。结果表明，该牛小卫星探针能产生具有个体特异性的鸭ＤＮＡ指纹图。通过用ＤＮＡ指纹图的（１－ＢＳ）值对７个鸭品系进行聚类分析还表明，该聚类图分析结果和各品系的来源及选育过程基本一致。     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.     

The Prevalence and Intensity of Helminth and Coccidial Infections in Dairy Cattle in Central Kenya

A survey of gastrointestinal parasite infections of young (<6 months old), immature (6–12 months old) and adult (>12 months old) dairy cattle on 16 farms in Kiambu District, Kenya was conducted during a dry season (September 1991 to January 1992) and during a wet season (March to July 1992). The survey was based on monthly coproparasitological examination of cohorts and worm counts in tracer calves. The effects of age, sex, farm and season on the prevalence and intensity of helminth and coccidial infections were determined. Faecal egg and oocyst counts revealed that the overall prevalences were: strongyles (including trichostrongyles) (85.5%), liver flukes (Fasciola gigantica) (34.0%), coccidia (30.9%) and tapeworms (9.6%). Eight species of the protozoan Eimeria were identified, the most prevalent species being E. bovis and E. zuernii. The most prevalent nematode genera were Haemonchus, Cooperia, Oesophagostomum and Trichostrongylus. Season, farm and age of the animals had a significant (p<0.05) influence on the intensity of infection with strongyles, liver flukes and coccidia, whereas the sex of the animals had no significant (p>0.05) effect on the prevalence or intensity of infections. A higher intensity of infection with strongyles and coccidia was found in the wet season than in the dry season (p<0.05). The age-specific intensity was in the following order: for strongyles, immature animals of 6–12 months of age had the highest egg counts, followed by young calves and adults. Calves had significantly (p<0.05) higher oocyst counts than immatures or adults. Liver fluke egg counts did not differ significant (p>0.05) between immatures and adult cattle.     

Hypothalamic dopamine is required for salsolinol‐induced prolactin secretion in goats

The aim of the present study was to clarify the relationship between hypothalamic dopamine (DA) and salsolinol (SAL) for the secretion of prolactin (PRL) in goats. SAL or thyrotropin‐releasing hormone (TRH) was intravenously injected into female goats treated with or without the D₂ DA receptor antagonist haloperidol (Hal), which crosses the blood‐brain barrier, and the PRL‐releasing response to SAL was compared with that to TRH. PRL‐releasing responses to SAL, Hal, and Hal plus SAL were also examined after a pretreatment to augment central DA using carbidopa (Carbi) and L‐dopa. The PRL‐releasing response to Hal alone was greater than that to SAL or TRH alone. The PRL‐releasing response to Hal plus SAL was similar to that of Hal alone. In contrast, the PRL‐releasing response to Hal plus TRH was greater than that to TRH or Hal alone. The treatment with Carbi plus L‐dopa inhibited SAL‐ and Hal‐induced PRL secretion. The inhibition of the PRL‐releasing response to SAL disappeared when SAL was injected with Hal. These results indicate that the mechanisms underlying the SAL‐induced PRL response differ from those of TRH, and suggest that hypothalamic DA and its synthesis is associated in part with SAL‐induced PRL secretion in goats.     

Laboratory diagnosis of respiratory diseases of cattle

The authors describe the procedure of laboratory diagnosis for bovine respiratory diseases: direct diagnosis by isolation and for identification of bacteria or viruses and indirect diagnosis by serological methods. They specify the restraints and limits of this diagnosis and the significance results which are obtained and connected with knowledge of anamnestic information.     

The effect of peri-parturient anthelmintic treatment on the productivity of dairy cattle in subtropical western India

Trials with fenbendazole (Panacur, Hoechst India Ltd) were carried out on two commercial farms in subtropical western India to study the response and economics of nematode treatment in adult dairy cows. Milk yield, lactation length, time to first oestrus and worm egg output were monitored in treated and control groups. Treatment reduced the egg count considerably. Treated cows produced 142 litres more milk over 100 days (p<0.05), with extension of lactation length and advancement of time to first oestrus. The economic gain in terms of milk yield far outweighed the cost of anthelmintic used.     

An Evaluation of the Acceptability as Forage of Some Nutritive and Antinutritive Components and of the Dry Matter Degradation Profiles of Five Species of Ficus

The suitability of five species of Ficus, F. mucoso, F. thonningii, F. polita, F. religiosa and F. benjamina, for feeding ruminant livestock was studied. The nutritive and antinutritive components were determined and the acceptability of the forages to livestock was assessed using a cafeteria method in 8 adult small ruminants. Also, the degradation potential of the dry matter of the five Ficus species was investigated using 3 fistulated sheep. The crude protein (CP) content of the Ficus species varied significantly (p < 0.05), ranging from 130 to 180 g/kg DM. The content of neutral detergent fibre (NDF) also varied significantly (p < 0.05), ranging from 650 to 710 g/kg DM. The organic matter (OM) contents did not differ significantly (p > 0.05), having a mean value of 916 g/kg DM. The concentrations of tannin, saponin, phytic acid and oxalic acid were low. The acceptability of the forage was similar for four of the species but poor for F. polita. The extent of DM degradation varied significant among the Ficus species, the ranking order being F. benjamina > F. thonningii > F. mucoso > F. religiosa > F. polita.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.