CACNA1S基因与低钾周期性麻痹

CACNA1S基因是L-型钙离子通道α1亚单位的编码基因,CACNA1S的基因突变会引起人低钾周期性麻痹及猪高温综合症,有关研究推测该基因是影响猪肉质性状的候选基因。笔者对CACNA1S基因的生物学特性、结构组成和CACNA1S基因突变引发的遗传病及CACNA1S基因的研究进展作了综合性阐述。     

鸡CACNA1S基因SNPs及其与部分屠体性状的关联性研究

为了研究L型钙离子通道α1亚单位(CACNA1S)编码基因与动物肌肉收缩和发育的关系,试验采用PCR-SSCP技术,首次对萧山鸡、仙居鸡、灵昆鸡、萧山鸡×仙居鸡杂交F1代、爱拔益加鸡(AA鸡)CACNA1S基因5’-调控区(5’-UTR)和外显子1进行多态性检测,同时结合屠体性状进行关联分析。结果表明:试验群体CACNA1S基因5’-UTR和外显子1存在2个单核苷酸多态性(SNPs)位点与屠体性状关联;SNPs716位点JJ基因型的胸肌率极显著大于KK基因型(P<0.01),SNPs1711位点YY基因型的胸肌率极显著大于XY和XX基因型(P<0.01),YY基因型的半净膛率极显著大于XX基因型(P<0.01)。初步推断CACNA1S基因可能是影响鸡部分屠体性状(全净膛率、半净膛率、胸肌率、腿肌率)的主效基因或与主效基因连锁,并且这些突变位点可能作为分子遗传标记用来选择鸡的屠体性状。     

猪SelS基因启动子区的克隆及序列分析

本研究旨在克隆和分析猪硒蛋白S基因(Selenoprotein S,SelS)启动子序列,并初步探讨潜在转录因子结合位点对其表达的影响.通过SON-PCR技术克隆猪SelS基因启动子序列,利用PromoterScan、Promoter 2.0等在线工具预测其启动子特征,利用细菌脂多糖(Lipopolysaccharides,LPS)刺激PK15细胞,研究NF-kappaB转录因子对猪SelS基因启动子活性的影响.试验获得了猪SelS基因约3kd的启动子序列,部分序列比对发现猪、人、牛和小鼠物种间相似性仅7%～51%.预测猪SelS基因转录起始位点在-398 bp,猪和人SelS基因启动子存在系列保守的转录因子结合位点,包括NF-kappaB、CCAAT box、SP1、USF等,但均未发现典型的TATA box.细胞试验表明,NF-kappaB转录因子可以上调猪SelS基因的表达.结果提示,物种间SelS基因启动子相似性较低,但猪和人SelS基因的转录因子非常保守,LPS诱导试验提示,猪SelS基因表达可能受NF-kappaB转录因子的调控.     

屠宰猪肝脏中乙型肝炎病毒的PCR检测与电镜观察

为探讨屠宰猪体内乙型肝炎病毒(HBV)流行情况,从北京某屠宰场采集肝脏样品,应用1对乙型肝炎病毒(HBV)S基因保守区的引物,采用PCR方法从屠宰猪肝脏中检测到HBV,序列分析表明,扩增片段与人HBV S基因的同源性高达99.05%;利用透射电镜观察到了样品中的病毒样离子。     

猪新基因NPM1的克隆、序列分析与染色体定位

克隆了猪NPM1基因的cDNA和第4内含子序列，并利用生物信息学方法进行验证。所得cDNA序列全长1195bp且包含一个完整的开放阅读框，编码294个氨基酸。内含子序列长300bp，遵循GT／AG剪接法则。序列分析表明，该基因与已报道的人、大鼠和小鼠等物种的NPM1基因高度同源，氨基酸序列同源性分别为95％、91％和91％。该基因编码的蛋白具有Nucleoplasmin保守功能域。用体细胞杂种板将该基因定位在猪16号染色体q21区段，辐射杂种板定位结果表明该基因与猪16号染色体上SW977标记紧密连锁。     

河北省邢台市及周边地区猪流行性腹泻病毒流行情况调查及S1基因序列分析

为初步调查河北省邢台市及周边地区猪流行性腹泻(PED)分子流行病学情况，试验于2022年1月—12月从河北省邢台市及周边县(市、区)采集疑似感染PED猪肠道病料或新鲜粪便共206份，采用荧光定量PCR技术检测样品猪流行性腹泻病毒(PEDV)阳性率；同时采用RT-PCR法扩增部分PEDV阳性病料S1基因序列，根据S1基因序列特征分析毒株基因型和变异情况。结果显示：共47份样品为PEDV核酸阳性，平均阳性率为22.82%,其中腹泻仔猪、育肥猪和母猪样品PEDV检出率分别为27.05%、15.15%和20.83%;采用RT-PCR法共扩增6份PEDV阳性样品S1基因部分序列，进一步序列分析发现5个毒株属于PEDV变异株，1个毒株属于PEDV经典株。研究结果表明，河北省邢台市及周边地区PED流行情况较严重，且同时流行PEDV经典株和变异株，但PEDV变异株为优势基因型。     

猪SKP1基因的克隆及其在梅山猪与杜洛克猪卵泡中的表达研究

为探索SKP1(S-phase kinase association protein 1)基因在猪卵泡中的表达规律,本试验从猪卵泡组织中克隆了猪SKP1基因CDS区全长序列,采用Real-time PCR方法检测SKP1基因在不同组织中的表达谱,进一步分析了该基因在梅山猪和杜洛克猪S卵泡、M1卵泡、M2卵泡、L卵泡中的表达。结果表明,经克隆测序,得到了猪SKP1基因492 bp编码区全长序列,与羊、人、黑猩猩、牛、大鼠的同源性分别为93.10%、92.90%、92.29%、91.89%、89.86%。SKP1基因在各组织中均有不同程度的表达(肌肉、脂肪、心脏、肝脏、脾脏、肺脏、肾脏、胃、十二指肠、卵巢、输卵管、子宫、子宫角、垂体、黄体、大脑、下丘脑),其中在子宫、脾脏、输卵管中表达量较高。SKP1基因的表达量在梅山猪S卵泡、M1卵泡和M2卵泡中的表达量均高于杜洛克猪,特别是在梅山猪M1卵泡和M2卵泡中SKP1基因的表达量极显著高于杜洛克猪(P<0.01),分别达到了2.39、2.82倍,而在L卵泡中的表达量却是杜洛克猪高于梅山猪,结果提示SKP1基因可能参与猪卵泡发育过程。     

猪流行性腹泻病毒SZ株的分离与鉴定

从资阳某猪场发生腹泻症状的猪肠道内容物中分离得到一株病毒,经荧光检测、RT-PCR检测及序列分析鉴定后,证实该分离株为猪流行性腹泻病毒,命名为SZ株。PCR方法克隆S基因的部分片段,序列分析结果表明PCR扩增的部分S基因与其他毒株比对,结果表明与CH/XJUrumqi及韩国AF500215 S1的亲缘关系较近。     

猪肺炎支原体S株的分离与鉴定

从典型猪肺炎支原体病变肺组织传代分离到一株支原体,经培养特性、血清学鉴定、生化鉴定、PCR检测及测序分析证明其为猪肺炎支原体,纯化后命名为S株。将S株P46基因和P97基因R1区的氨基酸序列与其他菌种的相应序列进行同源性分析,该菌株P46基因氨基酸序列与其他菌种同源高达99%以上,P97基因R1区的氨基酸重复数为11个,不同于其他菌株;免疫原性试验结果表明该菌株具有良好的免疫原性。     

鸡传染性支气管炎病毒S1基因与猪IgG Fc基因在HeLa细胞中的融合表达

根据GenBank中发表的猪的IgG Fc段基因及鸡传染性支气管炎病毒(IBV)S1基因序列,设计并合成引物.以猪肝组织总RNA为模板扩增出猪IgG Fc基因,以舍全长IBV M41 S基因的质粒为模板扩增出IBV S1基因,分别克隆至T裁体.DNA测序表明,所获得的IBV S1基因大小为1.5 kb,lgG Fc大小为1 kb,序列正确.将IBVS1与IgG Fc基因串连,插入舍有人组织型纤维蛋白溶酶原激活物分泌信号肽序列(tPA)的真核表达载体pcDNA3.1-tPA上,在HeLa细胞上进行瞬时融合表迭.经免疫光和斑点杂交检测,表达产物同时具有IBV S1蛋白和IgG Fe活性.     

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 -