比格犬MC3R和MC4R基因多态性与体重相关性的研究

犬体重是重要的经济性状,为探讨犬MC3R和MC4R基因多态性与犬体重性状的关系,本研究利用PCR-R FLP、AS-PCR方法对120只比格犬MC4R基因T101N位点,MC3R基因的A167T位点,G291A位点的不同基因型与体重的关系进行最小二乘分析、结果表明:对于MC4R基因NN基因型的比格犬体重显著高于其他2个基因型(P<0.05),而MC3R基因中TT和AA基因型的比格犬体重则显著高于其他2个基因型(P<0.05)。在MC4R基因型一致时,NNTT和NNAA基因型的犬体重显著高于其他合并基因型(P<0.01),NNTTAA合并基因型的犬体重最高,MMAAGG基因型犬体重最低。实验结果表明,MC3R和MC4R基因可以作为犬体型的候选基因,可筛选MC3R和MC4R合并基因型的犬用于培育不同体重的犬。     

MC3R和MC4R基因多态性位点与犬体型性状的关系

为了探讨犬MC3R和MC4R基因多态性与体质量等体型性状的关系,本研究利用PCR-RFLP、AS-PCR方法对已培育的北方实验用犬MC3R基因A167T,MC4R基因T101N多态性位点与体质量、体长、身高、胸围等体型指标的关系进行分析.结果显示,这2个多态性位点的基因型与犬的体质量、胸围和体质量指数(BMI)等呈显著性相关.另外,方差分析显示MC3R和MC4R合并基因型对体质量、胸围和体质量指数影响显著,MC3R和MC4R基因对体型性状的影响有协同作用.结果表明,MC3R、MC4R基因可以作为犬体型性状的候选基因,可选不同MC3R和MC4R合并基因型的犬用于培育小型或大型实验用犬.     

新发现的两个犬黑素皮质素受体-4缺失突变的探讨

目的：克隆犬黑素皮质素受体-4（Melanocortin-4 receptor，MC4R）基因片段，寻找其多态性位点。方法：根据犬、人和鼠等的MC4R基因序列，设计MC4R基因特异PCR引物。提取：本地犬基因组DNA，PCR扩增MC4R基因部分片段，回收纯化，连接载体，转化入感受态细胞，扩大培养。质粒酶切鉴定后，送测序公司测序。结果：本地犬MC4R基因片段有2处A碱基缺失突变。结论：本地犬中存在MC4R基因的多态性。本实验的MC4R两处缺失突变可能影响转录而引起：MC4R基因功能的改变。     

罗威纳杂交犬MC4R基因多态性与体重体尺的相关性研究

为了探讨黑素皮质素受体4(melanoeortin receptor-4,MC4R)基因多态性对罗威纳杂交犬生长性状的影响,以罗威纳杂交犬混合DNA为模板,对MC4R基因进行PCR扩增,扩增产物直接测序筛选多态性位点。结果发现3个碱基颠换,分别是154 bp处T/C、755 bp处G/T及895 bp处T/C颠换,其中895 bp处T/C颠换存在于ApaⅠ酶切位点内,以此建立了基于ApaⅠ的PCR-RFLP检测方法,并对67只罗威纳杂交犬进行检测分析。结果表明,在受检罗威纳杂交犬中检测到AA(0.104)、AB(0.493)和BB(0.403)3种基因型,AB基因型体重显著高于BB基因型,AA、AB基因型胸围极显著高于BB基因型。可以考虑将MC4R基因作为犬体重、体尺性状选择的候选基因。     

大白猪MC4R、CDC16基因多态性及其与生长性状的关联分析

本研究旨在利用高分辨率熔解曲线(high resolution melt,HRM)分型方法检测大白猪黑素皮质素受体(melanocortin-4 receptor,MC4R)和细胞分裂周期蛋白16(cell division cycle 16,CDC16)基因的多态性,并对其与大白猪的生长性状进行关联性分析。试验共采集246头大白猪的耳组织样提取基因组DNA,对小群体样本进行PCR扩增后,通过测序方法寻找两个基因在该群体中的多态性位点,针对已发现的多态性位点设计HRM专用引物,利用HRM方法对大群体进行多态性检测,将所得结果与大白猪生长性状进行关联性分析。结果表明,在MC4R基因序列中检测到1个突变位点2207A>G,2个等位基因:A和G,3个基因型:AA、AG和GG;在CDC16基因第18外显子上检测到了1个突变位点837T>C,2个等位基因:T和C,2种基因型:TT和CT。χ~2适合性检验结果显示,2个基因的基因型频率和等位基因频率在2个种群中分布差异不显著,符合Hardy-Weinberg平衡定律(P>0.05)。多态信息含量(PIC)分析显示,MC4R基因在2个群体中均处于中度多态(0.25相似文献   

大白猪MC4R、CDC16基因多态性及其与生长性状的关联分析

本研究旨在利用高分辨率熔解曲线(high resolution melt,HRM)分型方法检测大白猪黑素皮质素受体(melanocortin-4 receptor,MC4R)和细胞分裂周期蛋白16(cell division cycle 16,CDC16)基因的多态性,并对其与大白猪的生长性状进行关联性分析。试验共采集246头大白猪的耳组织样提取基因组DNA,对小群体样本进行PCR扩增后,通过测序方法寻找两个基因在该群体中的多态性位点,针对已发现的多态性位点设计HRM专用引物,利用HRM方法对大群体进行多态性检测,将所得结果与大白猪生长性状进行关联性分析。结果表明,在MC4R基因序列中检测到1个突变位点2207AG,2个等位基因:A和G,3个基因型:AA、AG和GG;在CDC16基因第18外显子上检测到了1个突变位点837TC,2个等位基因:T和C,2种基因型:TT和CT。χ~2适合性检验结果显示,2个基因的基因型频率和等位基因频率在2个种群中分布差异不显著,符合Hardy-Weinberg平衡定律(P0.05)。多态信息含量(PIC)分析显示,MC4R基因在2个群体中均处于中度多态(0.25PIC0.5),而CDC16基因在2个群体中均处于低度多态(PIC0.25)。关联分析结果发现,MC4R基因对大白猪体重及日增重具有显著影响(P0.05),CDC16基因对大白猪体高、体长和体重等均具有显著影响(P0.05)。综上所述,MC4R与CDC16基因对大白猪的生长发育具有一定的影响,为后续大白猪肉质性状与生长性状的现代分子选育提供参考。     

鸡MC3R基因多态性与体重和体组成性状的相关研究

研究将鸡黑素皮质素受体3(MC3R)基因作为影响鸡体重和体组成性状的候选基因,以东北农业大学肉鸡高、低脂双向选择品系第六、七、八世代为研究对象,采用PCR-SSCP和测序方法检测了MC3R基因编码区的多态性位点,并分析了MC3R基因多态性对鸡体重的影响。结果在MC3R基因编码区发现了一个C273T单碱基突变,此多态性位点对第六世代和第八世代两个群体的7周龄体重和屠体重有显著影响。结果可为后续肉鸡体重性状的分子标记辅助选择提供理论依据。     

余姚市特种獭兔黑素皮质素受体11(MC1R)基因与毛色表型的研究

目的:研究MC1R基因多态性与獭兔毛色的关系。方法:本试验根据NCBI数据库家兔MC1R基因的编码序列设计引物,利用PCR技术,对余姚兔场的16个獭兔MC1R基因外显子进行克隆测序,得到外显子基因编码序列,并测序;运用Clustal X2、Bioedit等软件对序列进行比对,对MC1R基因进行多态性分析和比较。结论:海狸色、黑色獭兔在MC1R基因扩增片段2上存在A→G碱基突变,这个位点具有成为獭兔毛色性状分子遗传标记的可能性。     

鸽黑素皮质素受体4基因多态性与生长性状及体组成的相关研究

通过比对GenBank中鸡、鹅黑素皮质素受体4（MC4R,melanocortin receptor）基因DNA序列,找出保守序列设计引物,克隆了鸽的MC4R基因编码区985bp序列,与鹅、鸡、短尾猊、北极狐和犬类的同源性分别为94%、94%、91%、84%和84%。利用PCR-SSCP技术和DNA测序方法检测两群体鸽MC4R基因编码区序列的单核苷酸多态性,共检测出两个多态位点,最小二乘分析表明,T933C基因型对肉鸽群体活重、屠体重、全净膛有显著影响（P＜0.05）,对野生鸽群体生长性状无影响（P＞0.2）,多重比较显示,该位点AA基因型个体的活重、屠体重、全净膛显著高于BB基因型个体（P＜0.05）。MC4R基因可能是影响鸽生长性状和体组成的主效基因或与主效基因相连锁。     

野猪和家猪MC4R基因的分子扫描及两个变异位点的PCR-RFLP分析

黑素皮质素受体4是在人类肥胖研究中发现的重要调节因子,参与调节动物的体重、采食量和能量稳态。猪MC4R基因第7跨膜结构功能域的一个高度保守区内的错义突变(G→A)与脂肪性状相关显著。本研究对野猪、民猪、大白猪MC4R基因进行克隆测序,寻找新的多态位点;并对其中的HindⅢ和ClaⅠ位点的突变进行了酶切多态性分析,建立了基于限制性内切酶HindⅢ和ClaⅠ的MC4R基因型的PCR-RFLP分子检测方法。     

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.     

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