HSP70基因PCR-SSCP实验条件的优化

对HSP70基因PCR-SSCP的分析方法进行了优化,结果发现在凝胶浓度为15%,丙烯酰胺(Acr)和N,N′-亚甲基双丙烯酰胺(Bis)之比为29∶1的聚丙烯酰胺凝胶常温180V电压下,其产物的电泳效果较好,条带清晰,可以为其他SSCP分析方法提供参考。     

鹅肠道微生物区系的PCR-SSCP体系构建

聚合酶链反应 单链构象多态性分析（PCR SSCP）技术是利用DNA单链构象具有多态性进行基因检测的一种快速、简便、较灵敏的分析技术,但其影响因素很多。研究运用PCR SSCP技术分析鹅肠道微生物区系,探讨了凝胶浓度,胶联度,PCR产物的稀释倍数,电泳时间和温度,是否加甘油、尿素和λ 核酸外切酶等因素对SSCP图谱的影响。结果表明,凝胶浓度为12％,胶联度为39∶1,凝胶中不加甘油,电泳电压为120 V,在恒温环境中,试验重复性较好,条带较清晰。因而,在采用PCR SSCP技术分析不同的研究对象,需要对其参数进行最大程度的优化,才能获得试验的成功。     

牦牛LEPR基因第4外显子PCR-SSCP实验条件的优化

单链构象多态性(Single Strand Conformation Polymorphism,SSCP)方法是目前分析单核苷酸多态性(single nucleotide polymorphism,SNPs)较为有效,、简单的方法之一。为研究牦牛LEPR基因的SNPs,建立适合于牦牛LEPR基因第4外显子的PCR-SSCP分析方法,本研究对影响SSCP结果的凝胶浓度、交联度、电泳时间和甘油进行了优化试验。结果表明,凝胶浓度为12%,交联度29:1,不添加甘油,17℃在1×TBE缓冲液中电泳25小时为最佳试验条件。本研究结果可为进一步分析牦牛LEPR基因多态性奠定实验基础,同时为建立其他基因SSCP最优条件提供参考。     

固始鸡与安卡鸡F2资源群Myf5基因PCR-SSCP分析条件的优化

为进行固始鸡与安卡鸡F2资源群Myf5基因的多态性研究,建立适合于该资源群的Myf5基因PCR-SSCP分析方法,对影响单链构象多态性（SSCP）图谱分辨率的凝胶浓度、甘油浓度、电泳电压、电泳温度、电泳时间、PCR产物与上样缓冲液的比例、电泳缓冲液浓度、上样量等影响因素进行了比较系统的优化试验研究。结果表明：凝胶浓度10%、甘油浓度50%、上样量10μL、PCR产物与变性缓冲液比例为10∶10、电泳缓冲液为1×TBE、室温下300 V预电泳10 min后120 V电压电泳16 h,染色后条带细而清晰,能够准确分辨各基因型,为试验SSCP分析的最佳条件组合。     

固始鸡与安卡鸡F_2资源群Myf5基因PCR-SSCP分析条件的优化

为进行固始鸡与安卡鸡F2资源群Myf5基因的多态性研究,建立适合于该资源群的Myf5基因PCR-SSCP分析方法,对影响单链构象多态性(SSCP)图谱分辨率的凝`胶浓度、甘油浓度、电泳电压、电泳温度、电泳时间、PCR产物与上样缓冲液的比例、电泳缓冲液浓度、上样量等影响因素进行了比较系统的优化试验研究。结果表明:凝胶浓度10%、甘油浓度50%、上样量10μL、PCR产物与变性缓冲液比例为10∶10、电泳缓冲液为1×TBE、室温下300 V预电泳10 min后120 V电压电泳16 h,染色后条带细而清晰,能够准确分辨各基因型,为试验SSCP分析的最佳条件组合。     

利用正交设计对简易银染法的优化研究

用正交设计研究了DNA聚丙烯酰胺凝胶电泳(PAGE)凝胶的简易银染中各因素对银染效果的影响,通过PCR技术扩增了山西白猪第六世代15个耳组织基因组的两条微卫星DNA序列,这些序列经聚丙烯酰胺凝胶电泳分离和500ladder Marker标记跑板后,利用正交法设计简易银染法各因素的组合,对凝胶进行染色。试验结果表明,染色液用AgNO3浓度0.10%、显色用含NaOH1.50%、甲醛0.40%混合液、水温30℃时对PAGE凝胶染色的效果最好。     

PCR-SSCP技术在动物育种中的研究进展

PCR—SSCP技术是新近发展起来的一种分子生物学分析方法，由于其广泛和潜在的应用价值，已被广泛应用于医学和其他生命科学的研究中。本文介绍了PCR—SSCP技术的发展、特点及其在动物遗传育种研究中的应用和发展前景。     

绵羊朊蛋白等位基因多态性的研究

绵羊痒病的发生和易感性可受绵羊朊蛋白等位基因密码子136,154和171多态性的影响。利用SSCP电泳和非变性聚丙烯酰胺凝胶结合的方法对10只健康绵羊的朊蛋白等位基因154,171两个多态性位点进行检测,发现8只纯合子羊基因型为154RR171QQ,2只杂合子羊基因型为154RR171HR。表明该方法可以应用于此等位基因多态性的研究中。     

替米考星淀粉微球的制备及缓释性能的研究

以可溶性淀粉为原料,N,N′-亚甲基双丙烯酰胺为交联剂,采用包埋法制备了替米考星淀粉微球,通过L9(34)正交试验设计,以载药量和包封率的综合得分为指标,优化了替米考星淀粉微球的制备工艺;分别用激光粒度分布仪、扫描电镜和综合热分析仪对载药微球进行了表征。结果表明最佳工艺条件为：淀粉4 g、替米考星0.02 g、交联剂0.95 g、乳化剂0.75 g、反应时间1 h;影响因素的大小依次为：交联剂的质量＞替米考星和淀粉的投料质量比＞反应时间＞乳化剂的质量;按优化工艺参数制得的载药微球的总载药量2.24%,包封率为89.6%;替米考星载药微球具有一定缓释效果,其制备方法合理可行。     

高强度酚醛树脂交联剂成胶性能分析评价

交联剂主要分为有机交联剂、金属交联剂两大类别。传统交联剂体系多为单一体系,某一种交联物质单独与聚丙烯酰胺溶液发生反应形成凝胶,其凝胶特性优越性单一,适用限制条件多,不宜应用于矿场试验。本文从一个新的思路出发筛选出高效交联产品——高强度酚醛树脂交联剂,室内试验效果很好,并克服了传统交联剂低温、高矿化度环境下成胶强度低、甚至不成胶、凝胶不稳定易脱水等缺陷。高强度酚醛树脂交联剂是在两种交联剂用量不同条件下相互作用生成类似于金属交联剂性质的物质M和酚醛树脂类交联剂性质的物质N,两者分别与聚丙烯酰胺发生交联反应,两者的协同作用使之形成高质量凝胶,弥补了单一体系的缺陷,使之具有更广泛的适用性。     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

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.     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -