抑制素免疫及其基因工程疫苗的构建

本文叙述了抑制素的特性、免疫原性及来源途径,并论述了其对提高家畜繁殖力的作用,同时提出了抑制素基因疫苗构建的方法及基因疫苗的优势。     

Application of time-resolved fluorometry to immunoassays for bovine reproductive hormones

The principle of time‐resolved fluorometry with lanthanide chelates was established in the 1980s, but in the field of animal sciences it has not been widely applied to immunoassays. However, immunoassays that utilize time‐resolved fluorometry are possible alternatives to radioimmunoassays, since they can attain high sensitivity without safety risks. In this short review, we introduce the development of time‐resolved immunoassays for inhibin A, inhibin B and follicle‐stimulating hormone (FSH), and describe their application to the investigation of FSH regulation in male and female cattle. The results obtained using these newly developed immunoassays indicate that inhibin A acts as a feedback regulator for FSH secretion in female cattle, whereas inhibin A, and probably inhibin B, do so in male cattle.     

池养线纹尖塘鳢的生殖及全人工繁殖

引进线纹尖塘鳢野生幼鱼,在池塘驯养至性成熟,经多代的混合选育,2002年育出子二代以后亲本2 000尾。进行池塘人工诱导产卵、受精,连续4年间获得受精卵6 143.5万粒,孵育出仔鱼4 983万尾,孵化率81.1%,相对孵育仔鱼量为65.1尾/g,取得全人工繁殖成功。试验结果表明,线纹尖塘鳢的卵小,长径仅0.6~0.9 mm,短径0.4~0.6 mm,初孵仔鱼全长2.875 mm;仔鱼混合营养期短,仅2~3 d以上,这些特点对仔鱼成活率极为不利。     

Protection of olive planting stocks against parasitism of root-knot nematodes by arbuscular mycorrhizal fungi

The effects were investigated, under controlled conditions, of single and joint inoculation of olive planting stocks cvs Arbequina and Picual with the arbuscular mycorrhizal fungi (AMF) Glomus intraradices , Glomus mosseae or Glomus viscosum , and the root-knot nematodes Meloidogyne incognita and Meloidogyne javanica , on plant performance and nematode infection. Establishment of the fungal symbiosis significantly increased growth of olive plants by 88·9% within a range of 11·9–214·0%, irrespective of olive cultivar, plant age and infection by M. incognita or M. javanica . In plants free from AMF, infection by Meloidogyne spp. significantly reduced the plant main stem diameter by 22·8–38·6%, irrespective of cultivar and plant age. Establishment of AMF in olive plants significantly reduced severity of root galling by 6·3–36·8% as well as reproduction of both Meloidogyne spp. by 11·8–35·7%, indicating a protective effect against parasitism by root-knot nematodes. Infection by the nematodes influenced root colonization by AMF, but the net effect depended on the AMF isolate–olive cultivar combination. It is concluded that prior inoculation of olive plants with AMF may contribute to improving the health status and vigour of cvs Arbequina and Picual planting stocks during nursery propagation.     

Cohort-dependent seedling recruitment, survival and reproductive capacity of Tribulus terrestris

Knowledge of the population biology of the summer annual Tribulus terrestris can provide valuable information for managing the risk of its colonising crop fields. Because of spring‐summer crop management practices, fields can exhibit bare ground in late April and early May. In this situation, four cohorts in 2000 and three cohorts in 2001 were censused and monitored throughout the vegetative and reproductive season, in order to evaluate the relationship between time of emergence, survival, vegetative growth and plant reproductive capacities. To a great extent, seedling survivorship depended on emergence timing; the earlier the emergence of the seedlings, the higher was the proportion of survivorship (64% and 4%, for early and late emergences). The time of emergence also influenced plant development; in both years, surviving individuals of the first cohorts presented significantly greater plant biomass and larger numbers of reproductive structures (60.5 fruits per plant) than those of later cohorts (0.8 fruits per plant). Reproductive meristem allocation was also highest in the earliest cohorts. Results showed that T. terrestris can increase its population size in fields if gaps of bare soil surface are available from mid spring to early summer.     

上海PMWS并发PRRS自然病例的病理组织学观察

对上海5例5～13周龄断奶仔猪多器官衰竭综合征（PMWS）并发猪繁殖与呼吸综合征（PRRS）自然病例进行了病理组织学观察。结果：5例病猪均出现坏死性淋巴结炎、间质性肺炎以及不同程度的坏死性脾炎、间质性肾炎和肝炎。2例病猪出现心肌炎，表现为心肌纤维断裂、溶解和心肌间质中淋巴细胞局灶性浸润。2例病猪出现脑炎，在大脑白质区出现神经胶质细胞结节。     

不同种昆虫病原线虫对同一寄主个体的竞争及对线虫繁殖的影响

采用注射侵染和自然侵染法，测试了长尾斯氏线虫X-7品系、小卷蛾斯氏线虫All品系和嗜菌异小杆线虫H06品系对同一寄主大蜡螟幼虫的相互作用，及其对线虫繁殖的影响。结果表明，无论是注射侵染还是自然侵染法，对大蜡螟幼虫个体的致死竞争能力最强的是长尾斯氏线虫，其次是小卷蛾斯氏线虫，嗜菌异小杆线虫的致死能力最弱。在同一大蜡螟幼虫体内时。异小杆线虫的繁殖受斯氏线虫的不利影响较大，而两种斯氏线虫的繁殖受异小杆线虫的不利影响较小。两种斯氏线虫对各自的繁殖影响不大。     

Population structure of poplar rust Melampsora larici-populina in the UK inferred from AFLP

AFLP profiles were generated from poplar leaf rust ( Melampsora larici-populina ) collected from Populus trichocarpa cv. Trichobel at six sites in the UK in 2001. Of a total of 145 isolates, 121 were unique AFLP phenotypes. On one occasion, the same AFLP phenotype was found at two sites. The analysis indicated that 81·88% of the total variation was attributable to differences among individuals within replicate plots, 3·47% to differences among plots within sites and 14·65% to differences among sites. Weir & Cockerham's θ was calculated as 0·138 and θ ^B , the Bayesian analogue of F _ST, as 0·146. Overall, there was sufficient gene flow among different sites to prevent genetic drift, as Nm was calculated as 1·562 using θ and as 1·462 using θ ^B . Nei's genetic distance and population-assignment test indicated that the rust from a site in north-east England was differentiated from those from other sites. There was no significant correlation between genetic and geographical distances. The results indicate that sexual reproduction has a major influence on the relative lack of population structure of M. larici-populina in the UK.     

Epidemiological Observations in a Corriedale Flock affected by Brucella ovis

Brucellosis in sheep, caused by Brucella ovis, is primarily a chronic infectious disease of rams with epididymitis as its most characteristic lesion. Six hundred rams from an infected farm were clinically and serologically examined once a year, over a 3-year period. An increase from 2.1% to 6.3% in the prevalence of animals serologically positive to B. ovis occurred over the 3 years. However, the prevalence of rams with lesions in the reproductive tract declined from 14.2% to 6.5% in the third year following one year of strict culling of clinically affected and rams that were serologically positive for B. ovis. Clinical lesions found in the 179 affected rams fell into two main categories: rams with epididymitis and rams with affected lymph nodes. These results suggest that the prevalence of the disease relates mainly to the sexual activity of the animal and not to age in itself. A single cull based on the results of clinical examination and serological test results was unable to decrease the prevalence of B. ovis in an extensive Corriedale sheep flock.     

耦合水文情势及鱼类繁殖的江垭水库生态调度需求研究（生态调度专刊）

大型水库实施生态调度是修复河流水文情势、维持河流生态系统健康的重要手段。江垭水库位于溇水干流下游的张家界慈利县，是澧水流域具有重要防洪意义的大型水库。本研究通过环境DNA采样、IHA水文指标变动分析和文献资料总结等方法，开展了江垭坝下水文情势及鱼类繁殖需求的关系研究，提出了江垭水库生态调度需求及建议。2021年9月在溇水干支流综合调查到鱼类55种，与上世纪90年代相比，流水性种类在干流江段显著减少了51.35%；按照生态调度优先等级评估原则，确定江垭水库生态调度的主要目标物种为产漂流性卵的银鲴、银鮈、贝氏?和产粘沉性卵的鲤、鲫；江垭建坝前后下游水文情势变化较大，发生高度改变且对鱼类洄游产卵及鱼卵发育有重要作用的水文指标包括：年最大1日、3日平均流量指标，年出现高流量脉冲事件的次数和持续时间，以及连续日流量上涨率。以促进坝下不同产卵类型的鱼类繁殖为目标，江垭水库生态调度一方面需要恢复一定的高流量脉冲次数和历时，另一方面需要控制下游的水位日降幅，通过泄放合理的生态流量来维持下游鱼类的生物多样性。