应用RAPD技术对中国3品系实验用小型猪进行亲缘关系的分析

随机扩增多态ＤＮＡ (ＲａｎｄｏｍＡｍｐｌｉｆｉｅｄｐｏｌｙｍｏｒｐｈｉｃＤＮＡ ,ＲＡＰＤ)技术 ,在动物、植物、微生物种属鉴定 ,亲缘关系的划分及多态性分析中得到广泛应用 ,但应用于小型猪方面的研究报道很少 ,尤其是对我国特有的实验用小型猪的研究 ,目前国内外尚未见报道。贵州小型香猪、广西巴马小型猪及西双版纳近交系小耳猪由于其近交程度高、遗传性稳定以及良好的实验应用效果 ,已引起了国内外相关领域的关注。本实验应用 1 0 0条随机引物对上述 3品系小型猪的基因组ＤＮＡ进行ＲＡＰＤ研究 ,旨在筛选具有品系间多态性的ＲＡ…     

广西巴马小型猪21个微卫星座位的DNA多态性分析

利用21个微卫星座位统计了广西巴马小型猪品系内的等位基因组成，计算了各位点的基因纯合率和多态性信息含量（PIC）及平均杂合度。结果，21个位点的平均基因纯合率为55．5％，平均PIC为0．3501，平均杂合度为0．3881。结果提示，广西巴马小型猪具有一定的遗传稳定性，已成为一个稳定的遗传群体，符合封闭群动物的遗传特征。     

荣昌猪和两种小型猪遗传背景的微卫星分析

荣昌猪是我国优良地方品种,巴马香猪和贵州小型香猪为我国独特小型猪品系。本研究采用美国猪基因组协作计划推荐的19个微卫星标记对荣昌猪、荣昌猪B系、巴马香猪、贵州小型香猪及外来猪种大白猪进行了遗传学检测和分析。结果表明:19个微卫星位点在群体中均表现为多态,每位点等位基因数10~23个。5个猪种中荣昌猪B系的遗传多样性最高,荣昌猪次之;2种小型猪的遗传多样性较低,其中巴马香猪的等位基因数(121个)略大于贵州小型香猪(114个),但其遗传多样性指数(平均期望杂合度0.6535±0.0347)小于贵州小型香猪(0.6919±0.0227),反映了巴马香猪较低的基因杂合度和较小的遗传变异;大白猪的遗传多样性最低。从品系的共有等位基因来看,荣昌猪B系基因背景组成中其亲本品系荣昌猪所占比例(30.22%)要大于大白猪(24.37%);大白猪和其他4个猪群体的共享等位基因数均较低(21.24%~25.12%);巴马香猪和贵州小型香猪之间共有等位基因数最高(45.06%)。采用基于遗传距离的NJ法和基于基因频率的最大似然法进行系统聚类,除了大白猪明显为独立分支及荣昌猪B系表现出较远的聚类关系外,其他3个猪种间的聚类有所不同。     

3个中国实验用小型猪品种血液生化指标分析

用全自动生化分析仪检测了五指山小型猪近交系、贵州小型猪和广西巴马小型猪封闭群25个血液生化指标，统计分析结果显示，3个品种间无差异的指标有1项，差异极显著（P＜0.01）的指标有7项；3个品种中所有指标的变异系数平均值依次为：0.18、0.21和0.17。通过3个小型猪品种间同一指标的比较，以及与人类参考值、国外著名的哥廷根小型猪、地方猪品种和引进大型猪品种比较，为小型猪用于人类医学研究应用提供参考。     

中国实验用小型猪种群血液生理指标分析

用全自动血液分析仪检测了五指山小型猪近交系、贵州小型猪和广西巴马小型猪封闭群18个血液生理指标，统计分析结果显示3个品种间无差异的指标仅有1项，差异极显著（P＜0.01）的指标有6项；这18项指标在上述3个品种中的变异系数平均值依次为0.243、0.19和0.182。通过3个小型猪品种间比较，以及与人类参考值、国外著名的哥廷根小型猪、地方猪品种和引进大型猪品种比较，为小型猪用于人类医学研究应用提供参考。     

利用微卫星标记对中国4种小型猪的遗传多样性研究

本研究通过10个微卫星位点对我国特有的4个小型猪种（五指山猪、滇南小耳猪、贵州小型香猪、巴马香猪）进行了遗传学检测，结果表明：除S0003位点表现为单态外，其它9个位点均为高度或中度多态位点；4个小型猪种群体内的遗传多样性比较高，平均基因杂合度分别为0.7165，0.6611，0.6602，0.5990；多态信息含量在0.5774－0.6871之间；五指山猪与贵州小型香猪的遗传距离较近，与滇南小耳猪次之，它们与巴马香猪都较远。     

滇南小耳猪与巴马小型猪SLA-DQA基因多态分析

对滇南小耳猪和巴马小型猪的SLA-DQA基因的部分内含子1、完整的外显子2和部分内含子2共341bp片段进行了PCR-RFLP酶切分型,结果表明：2品种经EcoR Ⅰ酶切后BB基因型频率（0.468 8）高于AB型（0.375 0）,AA型最低（0.156 3）,B为优势基因（0.656 3）,A为劣势基因（0.343 7）.经AluⅠ酶切后,滇南小耳猪MM基因型频率（0.500 0）高于MN型（0.321 4）和NN型（0.178 6）;而巴马猪则以MN基因型频率（0.485 3）高于MM型（0.338 2）和NN型（0.176 5）;2个品种中M等位基因（0.604 2）频率高于N等位基因（0.395 8）.经分析表明,2猪种在两酶切位点上各分型已达Hardy-Weinberg平衡.巴马小型猪和滇南小耳猪中分别存在9种和7种PCR-RFLP组合基因型,其中BBMN为优势组合基因型,AAMN为劣势组合基因型;AAMM组合基因型在2品种间差异显著（P＜0.05）.遗传多态参数分析表明：SLA-DQA基因外显子2的两酶切位点在2猪种间均表现为中度多态,AluⅠ的基因多样性略高于EcoRⅠ,巴马小型猪杂合性略高于滇南小耳猪,2品种间遗传距离为0.000 4.     

中国实验用小型猪生化标记检测研究

本试验采用聚丙烯酰氨凝胶电泳法,对我国实验用小型猪生化标记实行相应的探究。收集五指山小型猪、贵州小型猪、广西巴马小型猪和山东莱芜猪等的血液样品,检测了不同品种猪碱性磷酸酶(APK)、转铁蛋白(Tf)、蛋白抑止物(Pi-1)、后白蛋白(Po-2)、葡萄糖6磷酸脱氢酶(G6PD)、乙醇脱氢酶(ADH3)、醛缩酶(ALDA)、碳酸酐酶(Ca)和谷氨酸脱氢酶(GLD)等9个生化标记位点。结果显示:所检测的4个品种猪、9个生化标记位点中的ADH3、GLD、ALDA三个位点电泳呈现单条带,不存在多态性;其他6个位点都存在多态性。此外,还发现G6PD和Ca两个位点在五指山小型猪、贵州小型猪、广西巴马小型猪品种和山东莱芜猪中表现型有明显不同。经对所统计数据与结果进行相应的分析与总结,确定了4个类型猪的遗传性变异、体系构造及种类之间的遗传联系等;并从此方向揭示了我国现存实验用小型猪的遗传多样性情况,丰富了我国地方猪种遗传资源数据库。     

广西巴马小型猪MyoG基因克隆及外显子3多态性分析

为了解RT-PCR扩增广西巴马小型猪肌细胞生成素(MyoG)cDNA序列,并分析与其他物种间的聚类关系,试验采用PCR-SSCP技术分析广西巴马小型猪、长白猪、杜洛克猪、大约克猪MyoG基因外显子3多态性,根据GenBank中已发表的猪MyoG基因序列设计PCR引物,以广西巴马小型猪肌肉组织总RNA为模板进行RT-PCR,所得目的片段经纯化、克隆、鉴定和测序;从4个猪种的耳组织中分别提取30个个体的基因组DNA,采用PCR的方法扩增出外显子3并进行SSCP分析。结果表明:克隆得到广西巴马小型猪MyoG基因编码区长675 bp,与四川野猪、人、奶牛、小鼠同源序列相似性分别为99.7%、93.8%、91.7%、90.5%,且不同物种间保守性较强;与四川野猪相比,克隆得到的广西巴马小型猪MyoG cDNA序列在第233位点及第642位点上发生基因突变;广西巴马小型猪MyoG基因的基因型只有AA型,而长白猪、杜洛克猪、大约克猪MyoG基因的基因型只有AB型,各群体内无多态性。     

6个中国小型猪种SLA-DQB基因外显子2多态性分析

采用PCR-RFLP法对甘孜藏猪、合作猪、滇南小耳猪、荷包猪、五指山猪和巴马小型猪SLA-DQB基因外显子2多态性进行分析。结果表明:经RsaⅠ酶切检测到5种等位基因,14种RFLP带型,遗传杂合度(He)在0.538~0.729,多态信息含量(PIC)在0.488~0.728,该位点表现为高度多态;χ~2适合性检验显示,甘孜藏猪、巴马小型猪和五指山猪3个群体处于Hardy-Weinberg平衡状态。经HinfⅠ酶切检测到3种等位基因,6种RFLP带型,He在0.315~0.524,PIC在0.291~0.461,在该位点表现为中度多态。χ~2适合性检验显示,甘孜藏猪、滇南小耳猪、巴马小型猪、荷包猪4个群体处于Hardy-Weinberg平衡状态。因此,6个小型猪种的SLA-DQB基因外显子2多态性丰富且存在明显差异。     

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