蒙古马生长激素基因的克隆及部分序列的PCR-SSCP分析

通过PCR-SSCP方法对7个品种285匹马的生长激素基因做了多态性分析,在所检测的5′端侧翼区、第一内含子、第二外显子和第五外显子4个位点中,仅第五外显子检测到多态,该多态位点由A和B两种等位基因控制.GH基因第1 719处1个T→C的突变和1 743处G→A的突变,导致等位基因B变为等位基因A.除纯血马外,A基因在各品种中均为优势等位基因,B基因为纯血马的优势基因.在此多态位点,乌珠穆沁马、乌审马和巴尔虎马处于Hardy-Weinberg平衡状态,纯血马、三河马和锡尼河马则未达到Hardy-Weinberg平衡状态.     

猪2,4-双烯-辅酶A还原酶（DECR1）基因的多态性研究

选取山西马身猪、山西白猪、长白猪、大白猪和杜洛克猪5个品种共454头,采用PCR-SSCP技术,检测了DECR1基因第5外显子位点的遗传多态性.结果显示,DECR1基因第5外显子位点存在多态性,表现出CC、CD、DD三种不同基因型.群体遗传学分析结果表明,除山西马身猪外,其余品种都是等位基因D为优势基因;Hardy-Weinberg平衡检验显示,长白猪、大白猪、山西白猪处于平衡状态,山西马身猪、杜洛克处于非平衡状态;各品种猪的多态信息含量均表现为中度多态,PIC值均在0.3629～0.3748之间.     

马COMT基因第4外显子多态性分析

探讨COMT基因第4外显子(C4位点)多态性,进而探究不同品种马在该位点的遗传变异程度和选育强度。采用PCR-SSCP方法对不同品种马的COMT基因C4位点进行多态性分析。结果表明:第4外显子区域存在多态现象,发现AA、BB 2种基因型,并有3处突变分别是13处C突变为A、199处C突变为G的颠换、120处T突变为C的转换。不同品种间的基因型分布存在差异,纯血马的优势基因型和优势等位基因是BB型和B;而乌审马、锡尼河马、三河马、巴尔虎马、乌珠穆沁马的优势基因型和优势等位基因均为AA型和A;处于哈代-温伯格平衡状态(P0.05)的只有巴尔虎马,其他品种马都没有处于哈代-温伯格平衡状态(P0.01)。纯血马C4位点的杂合度为0.499,多态信息含量为0.374,呈中度多态性。纯血马C4位点杂合度和多态信息含量较高,表明该群体的遗传物质基础一致性较高,该位点遗传性能趋于稳定。     

马生长激素基因多态性与体尺指标之间的关联性分析

为研究广西德保矮马、百色马和新疆伊犁马的生长激素(GH)基因多态性与体尺指标之间的相关性,本实验利用PCR-SSCP技术分析3个品种277匹马GH基因5′侧翼区、第3外显子、第4外显子、第5外显子的遗传多态性。结果表明:只有GH基因第5外显子出现多态性,表现为AA、BB和AB 3种基因型,其他片段未发现多态性。群体遗传学分析表明,等位基因A和B的基因频率相等;Hardy-Weinberg平衡检验显示,3个品种马均处于非平衡状态;它们的多态信息含量均为中度多态。统计分析表明,GH基因第5外显子的基因型与3个品种马体尺指标之间无显著相关性。     

5个猪种DECR1基因外显子2单链构象多态性的群体遗传学分析

试验利用PCR-SSCP技术检测了山西马身猪、山西白猪、长白猪、大白猪和杜洛克猪5个品种共490头猪的DE-CR1基因外显子2的多态性。结果显示,DECR1基因外显子2位点存在多态性,表现出AA、BB和AB 3种基因型。群体遗传学分析结果表明,5个猪种都是等位基因B为优势基因;Hardy-Weinberg平衡检验结果显示,山西白猪和杜洛克猪处于平衡状态,山西马身猪、长白猪和大白猪处于非平衡状态;各品种猪的多态信息含量均为中度多态。     

中国南方荷斯坦奶牛κ-CN基因第四、第五外显子的多态性研究

本文利用PCR-RFLP技术，检测了中国南方荷斯坦牛κ-酪蛋白（κ-casein，κ-CN）基因第4、第5外显子的遗传多态性。结果表明：κ-CN基因第4、第5外显子均存在遗传多态性，第4外显子上存在突变位点g．10943A〉C，第5外显子上存在突变位点g．15153T〉C。第4外显子有两种基因型（AA，AB），等位基因频率分别为0．9379和0．0621，第5外显子有三种基因型（AA，BB，AB），等位基因频率分别为0．6512和0．3488。κ-CN两个外显子PCR-RFLP位点的基因型分布符合Hardy-Weinberg平衡定律（p〉0．05）。κ-CN基因第4、第5外显子座位的多态信息含量分别为0．1097和0．3511，第4外显子呈现低度多态，第5外显子呈现中度多态；其杂合度、有效等位基因数分别为0．1165、1．1318和0．4543、1．8324。     

4个绵羊品种MHC-DRB3基因外显子2的多态性分析

采用PCR-RFLP方法分析4个绵羊品种（阿勒泰羊、中国美利奴肉用多胎品系、湖羊和陶塞特羊）MHC-DRB3基因第2外显子的多态性，并进行聚类分析以及基因杂合度和多态信息含量的计算。结果表明：在绵羊MHC-DRB3基因第2外显子第122、154、168、220和241 bp碱基处表现出多态性；χ2适合性检验结果表明，4个绵羊群体MHC-DRB3基因的第2外显子的PstⅠ酶切位点达到了Hardy-Weinberg平衡状态，TaqⅠ和HaeⅢ酶切位点多态性均未达到Hardy-Weinberg平衡状态；4个绵羊群体基因杂合度和多态信息含量值分别在0.693～0.774和0.662～0.738之间，表明4个绵羊品种具有丰富的遗传多样性；聚类结果表明，中国美利奴肉用多胎羊和湖羊亲缘关系最近，阿勒泰羊和陶塞特羊关系较远，与实际选育过程一致，MHC-DRB3多态性可作为绵羊育种标记进一步研究。     

麦洼牦牛UCP基因多态性及其与生长性状的遗传效应分析

为了探讨麦洼牦牛UCP2和UCP3基因多态性及其与生长性状的相关性,为牦牛育种工作中遗传标记的辅助选择提供数据参考,试验以97头麦洼牦牛为研究对象,采用直接测序法获得UCP2基因第1,2,3,4外显子及部分内含子和UCP3基因第3,6外显子及部分内含子序列,比对获得多态位点,研究其遗传多态性与麦洼牦牛生长性状间的关联性。结果表明:UCP2基因第4外显子检测到1个多态位点(T1 499C),第4内含子检测到2个多态位点(A1 766G、C1 925T); UCP3基因第6外显子检测到1个多态位点(T13 190C)。4个突变位点在麦洼牦牛粉嘴和纯黑类群中均处于HardyWeinberg平衡状态(P0. 05); 4个多态位点均表现为低度多态[多态信息含量(PIC)0. 25]。UCP2基因T1 499C位点CT基因型个体体重均值显著高于TT型(P0. 05)。说明麦洼牦牛UCP2和UCP3基因存在多态性,其中UCP2基因T1 499C位点可作为麦洼牦牛生长发育性状遗传育种辅助选择的分子标记。     

鸡MAOA基因外显子6的SNP分析

研究采用PCR-SSCP方法分析了吐鲁番斗鸡和新罗曼鸡单胺氧化酶A基因外显子6部分序列的多态性。结果表明：吐鲁番斗鸡单胺氧化酶A基因外显子6存在1个单核苷酸多态性（SNP）位点T-102C,产生AA、AB两种基因型;新罗曼鸡未检测到多态,只表现AA一种基因型。χ^2适合性检验结果表明：2个鸡种均处于Hardy—weinberg平衡状态（P〉0．05）,说明吐鲁番斗鸡单胺氧化酶A基因外显子6位点基因型频率的分布与新罗曼鸡差异极显著（P〈0．01）。     

7个牛品种PON2基因第9外显子SSCP分析及其外显子多态性扫描

对氧磷酶2（Paraoxonase-2,PON2）产物是脂肪代谢过程中的抗氧化酶,被确定为影响相关重大心血管疾病和人类寿命的重要候选基因。本研究利用直接测序法对PON2基因所有外显子进行多态位点扫描,利用PCR-SSCP技术对中国西门塔尔牛、鲁西牛、秦川牛、晋南牛、荷斯坦牛、摩拉水牛和尼里-拉菲水牛7个品种的478头个体PON2基因第9外显子T98C位点进行多态性分析。结果表明,PON2基因外显子上共发现4个单核苷酸突变位点,但均未引起氨基酸的改变;第9外显子扩增大小为167bp的片段存在单链构象多态性。除鲁西牛和荷斯坦牛外,其它5个品种牛在该基因座位都处于Hardy—Weinberg平衡状态（P〉0．05）。鲁西牛、南阳牛、晋南牛和荷斯坦牛4个群体处于中度多态（0．25〈PIC〈0．50）,其它3个牛种为低度多态。除摩拉水牛和尼里-拉菲水牛不存在AA基因型外,其它5个牛品种中均存在AA、AB、BB3种基因型,但优势等位基因在7个品种牛群体中存在差异,基因型频率在鲁西牛和南阳牛中AA〉AB〉BB;晋南牛则3种基因型频率之比约为1：1：1;中国西门塔尔牛则出现严重的偏态,B等位基因为绝对优势等位基因;2种水牛中,BB基因型为优势基因型,B等位基因为优势等位基因。利用SAS9．1软件GLM过程分析基因型均值,用邓肯法（Duncan’s）进行基因型间的多重比较,将该基因座不同基因型与7个牛品种间和鲁西牛6个年龄组（n=238）进行了差异分析,结果表明,不同基因型在品种间存在极显著的差异（P〈0．01）;鲁西牛各年龄组与各基因型间差异不显著（P〉0．05）,但各种基因型间存在有着极显著的差异（P〈0．01）。结合各种基因型个体在不同年龄组间的变化趋势,AA型个体可能具有相对较长的使用寿命。     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.     

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.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.     

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 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.