饲料碳水化合物水平对吉富罗非鱼幼鱼生长性能和血液主要生化指标的影响

【目的】研究不同碳水化合物(CBH)水平对吉富罗非鱼幼鱼生长性能、体成分和血液生化指标的影响,以确定其适宜添加水平。【方法】以CBH质量分数分别为20%,27%,34%,41%和48%的5组等脂纯化饲料,投喂初始体质量为(4.77±0.52)g的吉富罗非鱼幼鱼10周,测定并分析其对吉富罗非鱼幼鱼体质量增加率、特定生长率、鱼体营养成分、血脂含量和血清转氨酶活性等指标的影响。【结果】随着饲料CBH质量分数的升高,罗非鱼幼鱼的体质量增加率和特定生长率先上升后下降,在41%CBH组达到最高,并显著高于其余4组(P<0.05);饲料系数以27%CBH组最低;肝体比、脏体比随着饲料CBH水平上升而显著升高;蛋白质效率和蛋白质沉积率以41%CBH组最高,且显著高于20%,27%和34%CBH组(P<0.05)。全鱼和肝脏粗蛋白含量随着饲料CBH水平的升高而显著下降(P<0.05),全鱼和肝脏粗脂肪含量则显著升高(P<0.05)。幼鱼血清中的胆固醇和甘油三酯浓度、谷草转氨酶和谷丙转氨酶活性均在48%CBH组达到最高,且显著高于其余4组(P<0.05)。【结论】吉富罗非鱼幼鱼饲料中的CBH对蛋白质有节约作用,适宜添加水平可达41%;摄取CBH水平过高(48%)会导致脂肪肝和高血脂,并对鱼体肝脏功能造成损害。     

High-quality binary protein interaction map of the yeast interactome network

Current yeast interactome network maps contain several hundred molecular complexes with limited and somewhat controversial representation of direct binary interactions. We carried out a comparative quality assessment of current yeast interactome data sets, demonstrating that high-throughput yeast two-hybrid (Y2H) screening provides high-quality binary interaction information. Because a large fraction of the yeast binary interactome remains to be mapped, we developed an empirically controlled mapping framework to produce a "second-generation" high-quality, high-throughput Y2H data set covering approximately 20% of all yeast binary interactions. Both Y2H and affinity purification followed by mass spectrometry (AP/MS) data are of equally high quality but of a fundamentally different and complementary nature, resulting in networks with different topological and biological properties. Compared to co-complex interactome models, this binary map is enriched for transient signaling interactions and intercomplex connections with a highly significant clustering between essential proteins. Rather than correlating with essentiality, protein connectivity correlates with genetic pleiotropy.     

Genetic diversity in cowpea [Vigna unguiculata (L.) Walp.] as revealed by RAPD markers

The present study, using RAPD analysis, was undertaken to characterize genetic variation in domesticated cowpea and its wild progenitor, as well as their relationships. The materials used consisted of 26 domesticated accessions, including accessions from each of the five cultivar-group, and 30 wild/weedy accessions, including accessions from West, East and southern Africa. A total of 28 primers generated 202 RAPD bands. One hundred and eight bands were polymorphic among the domesticated compared to 181 among wild/weedy cowpea accessions. Wild accessions were more diverse in East Africa, which is the likely area of origin of V. unguiculata var. spontanea. Var. spontanea is supposed to have spread westward and southward, with a loss of variability, loss counterbalanceed in southern Africa by introgressions with local perennial subspecies. Although the variabilty of domesticated cowpea was the highest ever recorded, cultivar-groups were poorly resolved, and several results obtained with isozyme data were not confirmed here. However primitive cultivars were more diverse than evolved cultivars, which still suggests two consecutive bottlenecks within domesticated cowpea evolution. As isozymes and AFLP markers, although with a larger number of markers, RAPD data confirmed the single domestication hypothesis, the gap between wild and domesticated cowpea, and the widespread introgression phenomena between wild and domesticated cowpea.     

多元统计分析方法在羊体质量与体尺研究中的应用

多元统计分析常用的方法包括回归分析、主成分分析、因子分析、聚类分析、判别分析、相关分析等。全面、综合地分析羊多项体尺及体质量指标所反映的信息,对深入研究育种及生产实践有重要作用。对多元统计分析方法在羊体质量与体尺研究中的应用作出较全面的概述。     

南方主要枣品种授粉花粉离体培养的影响因子研究

以南方适宜栽培的6个枣品种花粉为材料,研究了枣花粉离体培养的影响因子对花粉萌发的影响。结果表明:枣花粉培养的适宜培养基中蔗糖含量为5%～15%,硼酸100～400 mg/L,适宜温度为25℃～30℃。硼酸对花粉管的生长影响尤其明显。     

数据融合技术在温室环境监控系统中的应用

多传感器数据融合技术是一门新兴前沿技术。针对目前温室环境监控的需求,提出了一种基于D-S证据理论和农业专家系统相结合的数据融合方法。实验结果表明,这种方法提高了温室环境参数测控的决策准确性,可显著改善温室环境的控制效果。     

<Emphasis Type="Italic">Oestrus ovis</Emphasis> larval myiasis among sheep and goats in Central Oromia,Ethiopia

A study was conducted to determine the prevalence, larval burden, and associated gross pathological lesions of Oestrus ovis in sheep and goats slaughtered at Luna export abattoir in Central Oromia from November 2007 to March 2008. For this purpose, a total of heads of 431 goats and 369 sheep were thoroughly examined for the presence of first (L1), second (L2), and third (L3) larval stages according to standard procedures. O. ovis larvae were detected in 349(94.6%) sheep and 381(88.4%) goats. All three larval instars were observed in each study months. Statistically significant variation (χ ² = 29.2676, df = 6, P < 0.05) was observed in the prevalence of O. ovis among small ruminants of different origins. Likewise, statistically significant (χ ² = 68.3, df = 4, P < 0.05) difference was recorded in the prevalence of O. ovis in sheep and goats among different study months. The overall monthly prevalence ranged from 77.7% in November to 98.8% in March. The prevalence of O. ovis in small ruminants of less than 1 year of age was significantly (χ ² = 8, df = 1, P < 0.05) higher than those with greater than 1 year of age. An overall proportion of 33.8%, 40.1%, and 26.1% were recorded for L1, L2 and L3, respectively. Whereas 6.8 monthly mean larval burden per individual infested animal was noticed. Out of the total infested heads in goats, 33.6% had catarrhal discharges, 16.8% purulent exudates, 64.83% rhinitis, 68.77% sinusitis, 14.2% pharyngitis, and 9.2% bloody exudates. Similarly, of the total infested heads of sheep, 18.9% purulent exudates, 80.8% rhinitis, 71.9% sinusitis, 13.5% pharyngitis, and 7.7% bloody exudates gross lesions were recorded.     

Independently evolved virulence effectors converge onto hubs in a plant immune system network

Plants generate effective responses to infection by recognizing both conserved and variable pathogen-encoded molecules. Pathogens deploy virulence effector proteins into host cells, where they interact physically with host proteins to modulate defense. We generated an interaction network of plant-pathogen effectors from two pathogens spanning the eukaryote-eubacteria divergence, three classes of Arabidopsis immune system proteins, and ~8000 other Arabidopsis proteins. We noted convergence of effectors onto highly interconnected host proteins and indirect, rather than direct, connections between effectors and plant immune receptors. We demonstrated plant immune system functions for 15 of 17 tested host proteins that interact with effectors from both pathogens. Thus, pathogens from different kingdoms deploy independently evolved virulence proteins that interact with a limited set of highly connected cellular hubs to facilitate their diverse life-cycle strategies.