蓖麻蚕染色体的核型研究

对蓖麻蚕雄蚕有丝分裂中期、减数分裂粗线期和雌蚕有丝分裂中期、减数分裂粗线期、双线期进行了染色体组型排列 ,并对不同时期染色体的相对长度进行了方差比较分析 ,结果发现 :不同时期染色体的核型基本一致 ,但也存在着明显差异的染色体。因此在考虑利用形态进行绢丝昆虫核型分析 ,以相对长度作为一个重要指标时 ,有必要将各个时期的核型相互参照。     

苏州樗蚕染色体观察

本文对苏州蚕专校园内楼息的樗蚕,进行了细胞学观察,结果在雌蚕卵原细胞有丝分裂中期,看到26条呈短杆状的染色体,在卵母细胞减数分裂双线期看到13对平行接合的二价染色体,由此,可判定该地樗蚕的染色体为2n=26,n=13,由于在双线期未发现单价体,故推定其性型为XX—XY型。关于其生物学性状及核型分析,拟待另报。     

绢丝昆虫染色体研究进展(续)

二、野蚕染色体研究的历史、现状与进展所谓野蚕(wild silkworm)即指家蚕以外的绢丝昆虫(田中,1943),多属于天蚕蛾科(saturniidae)和家蚕蛾科(Bombycidae).主要包括柞蚕、天蚕、蓖麻蚕、樗蚕、枫蚕、栗蚕、柳天蚕、姆咖蚕、惜古比天蚕、琥珀蚕、大乌柏蚕、野桑蚕及桑蟥等,而且主要分布在亚州、尤其     

家蚕三种染色体组型的比较分析

本文比较了家蚕三个不同品种的卵母细胞联合复合体组型、减数分裂染色体组型及雌蚕体细胞有丝分裂染色体组型.结果发现,三种组型的染色体相对长度无显著差异.据此提出家蚕三种组型能以有丝分裂组型为基准,互相参照比较.对雌蚕的异型性染色体及其在减数分裂中的配对行为进行了讨论.     

绢丝昆虫柳天蚕(Actias selene Hünber)的形态习性

1、本实验自1982年秋至1985年春,对重庆地区广泛分布的一种野生绢丝虫柳天蚕(Actias selene Hubner)的形态习性进行了调查研究,并获得初步结果。 2、调查发现柳天蚕在重庆地区为二化,以蛹态越冬,越冬蛹于翌年四月中、下旬羽化产卵,第一代幼虫五月上旬孵化,幼虫共五龄,六月上、中旬结茧化蛹,六月下旬羽化为成虫产卵;第二代幼虫七月下旬孵化,十月上旬开始结茧化蛹越冬。但各虫态时间在野外参差不齐,差异较大。 3、调查还发现,柳天蚕在本地区特别嗜好喜树(Camptothecn acuminatu Decue)叶(此树为中国特产)这在国内外文献记载甚少。 4、通过柳天蚕与同属于天蚕蛾科的中国柞蚕,日本柞蚕(天蚕)的性状比较,发现柳天蚕的诸多性状与中国柞蚕更为近似,但染色体数目却大为不同。     

6种野生蚕类的RAPD分析

野生蚕类是我国重要的泌丝昆虫资源,研究其亲缘关系对于发掘和利用野生蚕类资源具有重要意义。利用随机扩增多态性DNA(RAPD)技术分析大蚕蛾科的柞蚕、栗蚕、野生柞蚕、天蚕、蓖麻蚕、透目天蚕间的亲缘关系,利用从54个引物中筛选出的30个重复性较好的随机引物对6种野生蚕类的基因组DNA进行扩增,共得到632个RAPD标记,其中可变条带数为632条,单个引物扩增的条带数为15～27,平均为21.1。6种野生蚕类相互间的遗传距离(D)较大,说明相互间的亲缘关系较远,其中:蓖麻蚕和栗蚕的遗传距离最大,为0.761 2;天蚕和透目天蚕的遗传距离最小,为0.671 1。采用UPGMA法构建的聚类图显示6种野生蚕类聚为4类,柞蚕与野生柞蚕聚为一类,天蚕与透目天蚕聚为一类,栗蚕、蓖麻蚕各自单独聚为一类。     

柳蚕卵黄原蛋白(Vg)cDNA3′端的克隆及序列分析

柳蚕(Actias seleneHbner)是野生泌丝昆虫。从柳蚕雌蛹脂肪体中提取总RNA,根据已经解析出的其它泌丝昆虫的卵黄原蛋白cDNA序列设计特异性引物,对柳蚕卵黄原蛋白cDNA3′端进行RACE(rapid amplification ofcDNA ends)扩增,经克隆和测序得到了一条1 072 bp的cDNA片段,该序列与柞蚕(Antheraea pernyi)、天蚕(An-theraea yamamai)、野桑蚕(Bombyxmandarina)、家蚕(Bombyxmori)、樗蚕(Samia cynthia pryeri)、蓖麻蚕(Philosamiacynthia ricini)、樟蚕(Saturnia japonica)相应序列的同源性分别为82.5%、82.4%、67.0%、63.2%、80.3%、78.5%、81.0%。同源性分析表明,昆虫卵黄原蛋白的一级结构在进化上具有较高的保守性。     

柳蚕卵黄原蛋白(Vg)cDNA 3'端的克隆及序列分析

柳蚕(Actias selene Hubner)是野生泌丝昆虫.从柳蚕雌蛹脂肪体中提取总RNA,根据已经解析出的其它泌丝昆虫的卵黄原蛋白cDNA序列设计特异性引物,对柳蚕卵黄原蛋白cDNA 3'端进行RACE(rapid ampliftcation of eDNA ends)扩增,经克隆和测序得到了一条1 072 bp的cDNA片段,该序列与柞蚕(Antheraea pernyi)、天蚕(An.theraea yamamai)、野桑蚕(Bombyx mandarina)、家蚕(Bombyx mori)、樗蚕(Samia cynthia pryeri)、蓖麻蚕(Philosamia cynthia ricini)、樟蚕(Saturnia japonica)相应序列的同源性分别为82.5%、82.4%、67.0%、63.2%、80.3%、78.5%、81.0%.同源性分析表明,昆虫卵黄原蛋白的一级结构在进化上具有较高的保守性.     

柞蚕、(天蚕×柞蚕)F_1、蓖麻蚕蛹期血液及脂肪体酯酶同工酶凝胶电泳分离

本文报道了柞蚕、(天蚕×柞蚕)F_1、蓖麻蚕蛹期血液及脂肪体酯酶同工酶的聚丙烯酰胺凝胶电泳的不连续电泳图谱并试图探讨这些同工酶和蚕体内生理生化过程的某些关联,提出同工酶活性高低和蚕体内能量代谢有关的推测,试验结果表明:柞蚕血液及脂肪体的酯酶同工酶酶带较多,且颜色较深,而蓖麻蚕的较少,且颜色很浅、(天蚕×柞蚕)F_1介于二者之间。雌雄比较:血液酯酶同工酶活性全部雌强于雄、脂肪体酯酶同工酶活性全部雄强于雌,唯(天×柞)F_1例外。同一类蚕的不同个体,不同发育时期,不同器官,不同性别之间均存在差别。     

家蚕细胞遗传学的研究——家蚕幼虫雌粗线期染色体形态的分析

Ⅰ前言家蚕染色体研究,从外山(1894)开始,以雄蚕为材料,认为染色体数是14,但谷津(1913)发现为28,以后胜木(1918)、小熊(1919)、川口(1923)等均有研究.田中(1917)发现伴性油蚕,在实验上证明家蚕性型是尺蠖型(Abraxas),雌为异质性.但究竟为zw抑为zo尚未明确,川口(1928)发现家蚕雌卵母细胞染色体亦为     

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 -