小麦族内几种远缘禾草及其杂交种过氧化物酶同工酶分析

采用聚丙烯酰胺垂直板电泳技术对小麦族内的加拿大披碱草,野大麦及其杂种Ｆ１和蒙古冰草,航道冰草及其杂种Ｆ１ＢＣ１的过氧化物酶（ＰＯＤ）同工酶做了比较研究。结果表明,每种植物的ＰＯＤ酶谱可明显分成Ａ,Ｂ两区,在Ｂ区有２条位点相同的酶带,为亲本的基带,所有供试材料呈现６－９条酶带,亲本与其杂种后代的酶谱表型有一定差异,ＰＯＤ同工酶具有多态性,可作遗传标记用于杂种鉴定和回交后代目标性状植株的检测。加拿大披     

蒙古冰草与航道冰草正反交杂种染色体加倍植株F_2的ISSR分析

利用ISSR分子标记技术对蒙古冰草与航道冰草正反交杂种染色体加倍植株F2代间及其与亲本和杂种F1代间在DNA分子水平上的遗传差异性进行分析,结果表明:12个ISSR适宜引物共扩增出515个条带,多态性条带492个,多态性条带百分率为95.3%。6个供试材料间的遗传距离(GD)变幅为0.4094~0.6721,平均为0.5391,亲本航道冰草与蒙古冰草间、航道冰草与正反交杂种染色体加倍植株F2间的遗传距离较大,正反交F1间的遗传距离次之,正反交杂种染色体加倍植株F2间的遗传距离相对较小。以GD值0.51为基准,6个材料聚为3类:第一类为蒙古冰草、反交杂种F1,第二类为正交杂种F1、正反交杂种加倍植株F2,第三类为航道冰草。     

加拿大披碱草与老芒麦种间杂交及F1代细胞学分析

加拿大披碱草与老芒麦同属于禾本科小麦族披碱草属，均为异源四倍体，两个种的杂交为地理上远缘的种间杂交。试验采用将母本穗人工去雄后与相邻种植的父本穗套袋的方法获得了加拿大披碱草与老芒麦正反交的种间杂交种子。对亲本及杂种Ｆ１代花粉母细胞的减数分裂行为进行的分析结果表明，Ｆ１代杂种仍是四倍体，加拿大披碱草和老芒麦所含的两个染色体组之间具有同源性，但也发生了某种程度的结构变异；杂种Ｆ１代高度不育。     

几种小麦族禾草及其杂交后代农艺特性的研究

对几种小麦族多年生禾草及其杂交后代的生育、产草量等农艺特性进行了比较研究,结果表明,加拿大披碱草×野大麦属间杂种F1的生长速度偏向母本,株高呈双亲的中间型,具有父本野大麦的强短根茎特性和果后营养期长的优良特性,表现出很强的分蘖能力和再生能力,其花粉可育率为1.19%,结实率0,杂种平均优势16.98%。蒙古冰草×航道冰草种间杂种F1的生长速度和株高均介于双亲中间,具有父本航道冰草分蘖和再生能力强的特性,花粉可育率为26.75%,结实率5.30%,杂种平均优势19.35%;BC1的生长速度呈双亲的混合型,株高、分蘖性和再生性偏向其回交父本蒙古冰草,花粉可育率为46.67%,结实率14.77%,BC1育性恢复明显。     

以PCR为基础的分子生物学方法及其在寄生虫学方面的应用

扼要介绍了以聚合酶链反应（ＰＣＲ）为基础的随机扩增多态ＤＮＡ（ＲＡＰＤ）ＰＣＲ连接的限制性酶切片段长度多态性（ＰＣＲ－ＲＦＬＰ）扩增片段长度多态性（ＡＦＬＰ）等和ＤＮＡ序列分析在寄生虫学方面的应用及其优势和不足；叙述了检测寄生虫序列变异的几种新方法。     

披碱草和野大麦及其杂种F1与BC1代的RAPD分析

应用RAPD技术对披碱草Elymus dahuricus和野大麦Hordeum brevisubulatum及其杂种F1与BC1代的遗传差异性进行了研究.结果表明,各供试材料基因组DNA具有很高的多态性;依据遗传相似系数,亲本披碱草和野大麦之间的遗传差异较大,正、反交杂种F1均偏向披碱草遗传,正、反交F1间的遗传差异不显著,BC1代偏向轮回亲本野大麦遗传,不同株系间存在遗传差异.RAPD技术可用于禾草远缘杂种鉴定及目标性状植株检测的遗传标记.     

披碱草和野大麦及其杂种F1与BC1代的RAPD分析

应用RAPD技术对披碱草Elymus dahuricus和野大麦Hordeum brevisubulatum及其杂种F1与BC1代的遗传差异性进行了研究.结果表明,各供试材料基因组DNA具有很高的多态性;依据遗传相似系数,亲本披碱草和野大麦之间的遗传差异较大,正、反交杂种F1均偏向披碱草遗传,正、反交F1间的遗传差异不显著,BC1代偏向轮回亲本野大麦遗传,不同株系间存在遗传差异.RAPD技术可用于禾草远缘杂种鉴定及目标性状植株检测的遗传标记.     

结缕草属植物SRAP－PCR体系的建立和优化

以ＳＤＳ法提取的结缕草属植物叶片ＤＮＡ 为模板,分别采用单因子试验和正交设计试验２种方法,对影响结缕草属植物ＳＲＡＰ－ＰＣＲ 的MG²⁺ 、ｄＮＴＰ、引物、ＴａｑＤＮＡ 聚合酶和模板ＤＮＡ 五个因素进行优化试验。单因子试验分别研究各因素在多水平条件下对ＳＲＡＰ－ＰＣＲ 反应体系的影响,得到最佳反应条件。正交设计采用Ｌ１６（４５）方案,综合考虑各因素间的相互作用,通过直观分析法获得各影响因素的最佳反应水平。根据４对引物对６ 份结缕草属植物材料扩增结果的验证比较,２种方法所获得的最佳反应体系存在一定的差异。通过综合比较和分析２种方法的优化体系扩增出的条带数、多态性条带数及多态性比率,最终建立了结缕草属植物ＳＲＡＰ－ＰＣＲ 的最佳反应体系：MG²⁺２．００ｍｍｏｌ／Ｌ、ｄＮＴＰ２２０μｍｏｌ／Ｌ、引物０．２０μｍｏｌ／Ｌ、ＴａｑＤＮＡ 聚合酶０．５０Ｕ、模板ＤＮＡ６０ｎｇ、２μＬ１０×ｂｕｆｆｅｒ,总体积为２０μＬ。这一优化体系的建立为今后利用ＳＲＡＰ标记技术进行结缕草属植物遗传多样性、种质鉴定、遗传连锁图谱及亲缘关系分析等方面的研究提供了科学的依据。     

RAPD技术在动物遗传育种中的应用

ＲＡＰＤ技术在动物遗传育种中的应用龙火生方心葵（西北农业大学动物科学系陕西杨凌７１２１００１关于ＲＡＰＤ技术１９９０年,Ｗｉｌｉａｍｓ和Ｗｅｌｓｈ的两个研究小组几乎同时在各自的实验室建立了检测ＤＮＡ多态性的随机扩增多态ＤＮＡ（ＲａｎｄｏｍＡｍｐｌｉｆ...     

蒙古冰草与航道冰草正、反交F_1及其染色体加倍植株AFLP分析

利用AFLP分子标记技术,对蒙古冰草与航道冰草正、反交F_1及其染色体加倍植株的DNA多态性位点进行了比较分析.结果表明:用筛选出的11对适宜引物对供试材料进行AFLP扩增,共获得430条清晰的条带,其中多态性带396个,多态性比率高达92.1%;供试材料的遗传距离变幅为0.6594～0.8182,蒙古冰草与航道冰草遗传距离较远;以遗传距离0.72为基准可划分为3类,即亲本蒙古冰草与正反交杂种F1为一类、正反交杂种F1染色体加倍植株为一类、亲本航道冰草为一类.     

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