重组山羊FSH基因在毕赤酵母中的高效表达

为探讨快速高效表达山羊FSH（促卵泡素）基因的方法,将获得的FSHα,β亚基基因克隆到毕赤酵母快速表达载体pPICZαA中,然后将构建的载体线性化处理后,电击转化至毕赤酵母GS115中,经Zeocin抗生素筛选后获得阳性菌落,经甲醇诱导表达后进行SDS-PAGE和Western–blot分析。结果表明：pPICZαA载...     

山羊FSH真核表达载体pVITRO-FSHαβ构建及在CHO细胞内稳定表达

在对山羊促卵泡素α、β亚基基因克隆和瞬时表达的基础上，构建促卵泡素αβ双表达载体，并转染中国仓鼠卵巢细胞（Chinese Hamster Ovary Cells，CHO），在潮霉素B的抗性筛选下，进行稳定表达，获得了稳定表达的CHO细胞株，为重组激素制剂的研制提供了必备条件。     

鹅FSH基因原核表达

促卵泡激素（follicle stimulating hormone,FSH）作为调节家禽卵泡发育重要的候选基因,但FSH在生物体内的半衰期非常短,本试验将具有延长基因半衰期作用的CTP序列添加到鹅FSH基因各亚基的C末端进行基因融合,以期获得pET32a-FSHα-CTP、pET32a-FSHβ-CTP和pET32a-FSHβ-CTP-α重组蛋白。设计去除目的基因信号肽和含有酶切位点的特异性引物,经融合PCR扩增获得了目的基因FSHα-CTP、FSHβ-CTP和FSHβ-CTP-α,通过构建原核表达载体pET32a-FSHα-CTP、pET32a-FSHβ-CTP和pET32a-FSHβ-CTP-α,将重组质粒转化到大肠杆菌BL21（DE3）中,经IPTG诱导,SDS-PAGE检测,蛋白纯化。结果显示,3个融合蛋白FSHα-CTP、FSHβ-CTP和FSHβ-CTP-α的IPTG最佳诱导时间分别为4、5和5h,最佳诱导浓度分别为0.2、0.8和1.5mmol/L,且都是以包涵体形式存在,相对分子质量分别为32 000、35 000和46 000,与预期大小一致。结果表明,本试验成功构建了鹅pET-32a-FSHα-CTP、pET-32a-FSHβ-CTP和pET-32a-FSHβ-CTP-α的原核表达载体,并对它们的重组蛋白进行了纯化,为开展鹅FSH的基因免疫研究和鹅rFSH生物制剂研发奠定基础。     

山羊FSH及其长效类似物基因在小鼠乳腺中的暂态表达

应用山羊促卵泡素长效类似物基因构建其乳腺暂态表达载体pcDNAFSH-βCTP、pcDNAFSH-βCTP-α及构建报告基因pcDNAEGFP,测序后通过脂质体转染至怀孕末期的小鼠乳腺组织。结果表明,构建的乳腺暂态表达载体在小鼠乳腺中获得了表达,表达量分别为pcDNAFSHα,β(7.933±2.074)IU/L,pcDNAFSHα,-βCTP(9.311±2.995)IU/L,pcDNAFSH-βCTP-α(11.059±4.107)IU/L。     

梅花鹿促卵泡激素α亚基基因克隆与融合表达

以原构建的克隆载体为模板,PCR扩增梅花鹿FSHα亚基基因,TA克隆后经双酶切插入表达载体pGEX-6P-2,阳性克隆导入E.coli BL21,IPTG诱导表达GST-FSHα融合蛋白,SDS-PAGE进行分析鉴定。结果表明,FSHα PCR产物大小约380 bp,测序结果与GenBank序列一致;重组表达载体pGEX-6P-2-FSHα构建成功;融合蛋白经SDS-PAGE分析,结果发现,在分子质量39.3 ku处出现特异性蛋白质条带,说明梅花鹿FSHα亚基基因片段已在E.coli BL21中成功表达了FSHα-GST融合蛋白。     

FSHβ亚基基因多态性对猪产仔性能的影响

FSH是一种重要的生殖激素,在动物繁殖过程中起重要作用,由β和α两个亚基组成,激素功能的特异性由α亚基决定.本文综述了猪FSH β亚基基因调控区、编码区、内含子区域内发生的遗传变异及对产仔性能的影响,并就FSHβ亚基基因在猪育种实践中的应用提出建议.     

南江黄羊FSHβ亚基基因内含子1序列的测定及分析

利用GenBank中公布的牛、绵羊等动物FSHβ亚基基因序列设计引物,采用PCR法扩增并测定出南江黄羊FSHβ亚基基因内含子1(in-1)全序列(GenBank登录号为AY838283)。山羊FSHβ基因内含子1全序列长641 bp,A、C、G、T4种碱基分别占35．73%、13．88%、17．47%、32．92%,A T (68．65%)的含量远高于G C(31．35%)的含量。不同物种间FSHβ基因序列相似性的变异范围为24．1%～97．3%,分歧度则为2．6%～85．7%。利用FSHβ亚基基因内含子1序列进行的物种间系统发育分析结果与实际的物种演化顺序一致,表明它可用于物种间的系统发育分析。     

天府肉羊FSHβ基因SNPs及其与产羔数的关联分析

本试验选取334只天府肉羊、波尔山羊和成都麻羊为试验材料,对山羊FSHβ基因进行了PCR扩增,采用PCR-SSCP和SNP技术分析了该基因在山羊中的多态性。结果表明,试验羊FSHβ基因5′调控区存在第712位A→G突变,形成了AA、AB和BB 3种基因型。适合性检验和最小二乘分析结果显示,山羊FSHβ基因不同基因型的平均窝产羔数存在显著差异;天府肉羊和成都麻羊的FSHβ多态位点处于Hardy-Weinberg平衡状态(P0.05),波尔山羊极显著偏离了Hardy-Weinberg平衡(P0.01)。由此推测,FSHβ基因可能对于山羊繁殖性能具有较大影响或与控制繁殖性能的主基因连锁,可以尝试将其作为一个重要的分子标记用于山羊的育种实践。     

20个山羊品种FSHβ基因部分序列测定及与其它8个物种的序列比较分析

利用牛、绵羊等动物FSHβ亚基基因序列设计引物，采用PCR法扩增并测定出20个山羊品种（16个本地品种和4个引进品种）FSHβ亚基基因部分序列（GenBank登录号：AY838283和AY853276）。在测定出的FSHβ亚基基因731bp序列中，包括第1外显子全序列（1～61bp），第1内含子全序列（62～702bp）以及第2外显子部分序列（703-731bp），序列的A＋T含量（66．07％）高于G＋C（33．93％），编码7个氨基酸。在所有测定的序列中共检出3个突变位点，分别是78（-／A）、132（G／A）和343（G／A），这些突变都位于内含子1序列中，它们与产羔率之间的联系需进一步研究。利用山羊以及GenBank中其他8个物种的FSHβ基因内含子1序列进行系统发育分析，部分结果与传统生物分类不一致，可能是由于大部分物种的序列长度不足700bp以及物种之间的关系超过了属阶元的限制。     

也木勒羊抑制素α亚基基因克隆及其真核表达

为了克隆也木勒白羊抑制素α(inhibinα,INHα)亚基基因和表达其重组蛋白质,本试验采集发情期也木勒白羊卵巢组织,并从中快速抽提总RNA,以此作为模板并根据白羊INHα亚基基因编码区序列(GenBank登录号:XM_004004955.1)设计合成1对引物,经反转录扩增获得了也木勒白羊INHα亚基基因编码区全长序列。并将扩增产物克隆到表达载体(pEGFP-N1)的ScalⅠ和EcoRⅠ酶切位点之间,构建重组质粒pEGFP-INHα并转化大肠杆菌DH5α感受态细胞,后进行鉴定、测序,证明成功构建了INHα亚基基因的真核表达载体。将也木勒白羊INHα亚基基因与人、大猩猩、牛等动物的INHα亚基基因序列进行同源性比对分析,相似度都在50%以上,说明了抑制素基因具有高度保守性。用RT-PCR和Western blotting方法验证了INHα亚基基因的真核表达载体在BHK细胞中的成功表达及蛋白表达。     

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.     

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.     

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.     

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

Tropical Animal Health and Production -     

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.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

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