Impaired B and T cell antigen receptor signaling in p110delta PI 3-kinase mutant mice

Class IA phosphoinositide 3-kinases (PI3Ks) are a family of p85/p110 heterodimeric lipid kinases that generate second messenger signals downstream of tyrosine kinases, thereby controlling cell metabolism, growth, proliferation, differentiation, motility, and survival. Mammals express three class IA catalytic subunits: p110alpha, p110beta, and p110delta. It is unclear to what extent these p110 isoforms have overlapping or distinct biological roles. Mice expressing a catalytically inactive form of p110delta (p110delta(D910A)) were generated by gene targeting. Antigen receptor signaling in B and T cells was impaired and immune responses in vivo were attenuated in p110delta mutant mice. They also developed inflammatory bowel disease. These results reveal a selective role for p110delta in immunity.     

川油15核不育三系制种技术的应用研究

油菜显性核不育杂合型不育系8702AB及其转育的纯合型不育系38AB和全不育系38AC的不育株在苗期长势长相相似，物侯期基本一致，株型和花器官形态无明显差异，可恢性未发生变化。杂合型不育系8702AB及其纯合型不育系38AB的不育株率为50％左右，而全不育系38AC的不育株率为100％。不育系8702AB和38AC与同一恢复系(T1082)组配的杂交一代种在植株形态、花器官、恢复率、主要农艺性状及产量上无明显差异，全不育系38AC的制种产量显著高于杂合型不育系8702AB，提高制种产量76．18％。     

ABI3130xl全自动测序仪规模化测序的影响因素研究

【目的】提高利用ABI3130xl全自动测序仪对小麦与条锈菌互作的cDNA文库进行大规模测序的成功率,降低成本。【方法】将BigDye(BigDye(Teminator V3.1 Cycle Sequencing RR-100)分别稀释16,24和32倍设计测序的PCR反应体系,分析了EDTA溶液(125 mmol/L,pH 7.0)和醋酸钠溶液(3 mol/L,pH 5.2)以及不同模板类型等相关因素对测序结果的影响。【结果】BigDye稀释16倍的PCR反应体系的测序结果易出现染料峰,影响碱基正确读值;稀释32倍体系的测序结果中可用序列短,成功率低;稀释24倍体系测序结果的可用序列长且准确率高,为最佳反应体系。EDTA溶液和醋酸钠溶液可提高DNA纯化的质量,改善测序效果。以质粒DNA为模板测序较PCR产物直接测序效果好,通过控制模板质量可以提高测序成功率。【结论】利用优化体系共测得15 000条ESTs序列,其中有高读长序列13 080条,占87.2%,表明该优化体系简单有效,且可有效节约成本。     

Early season weed mapping in sunflower using UAV technology: variability of herbicide treatment maps against weed thresholds

Site-specific weed management is defined as the application of customised control treatments only where weeds are located within the crop-field by using adequate herbicide according to weed emergence. The aim of the study was to generate georeferenced weed seedling infestation maps in two sunflower fields by analysing overlapping aerial images of the visible and near-infrared spectrum (using visible or multi-spectral cameras) collected by an unmanned aerial vehicle (UAV) flying at 30 and 60 m altitudes. The main tasks focused on the configuration and evaluation of the UAV and its sensors for image acquisition and ortho-mosaicking, as well as the development of an automatic and robust image analysis procedure for weed seedling mapping used to design a site-specific weed management program. The control strategy was based on seven weed thresholds with 2.5 steps of increasing ratio from 0 % (herbicide must be applied just when there is presence or absence of weed) to 15 % (herbicide applied when weed coverage >15 %). As a first step of the imagery analysis, sunflower rows were correctly matched to the ortho-mosaicked imagery, which allowed accurate image analysis using object-based image analysis [object-based-image-analysis (OBIA) methods]. The OBIA algorithm developed for weed seedling mapping with ortho-mosaicked imagery successfully classified the sunflower-rows with 100 % accuracy in both fields for all flight altitudes and camera types, indicating the computational and analytical robustness of OBIA. Regarding weed discrimination, high accuracies were observed using the multi-spectral camera at any flight altitude, with the highest (approximately 100 %) being those recorded for the 15 % weed threshold, although satisfactory results from 2.5 to 5 % thresholds were also observed, with accuracies higher than 85 % for both field 1 and field 2. The lowest accuracies (ranging from 50 to 60 %) were achieved with the visible camera at all flight altitudes and 0 % weed threshold. Herbicide savings were relevant in both fields, although they were higher in field 2 due to less weed infestation. These herbicide savings varied according to the different scenarios studied. For example, in field 2 and at 30 m flight altitude and using the multi-spectral camera, a range of 23–3 % of the field (i.e., 77 and 97 % of area) could be treated for 0–15 % weed thresholds. The OBIA procedure computed multiple data which permitted calculation of herbicide requirements for timely and site-specific post-emergence weed seedling management.     

Strain C3H-A-vy-fB mice: ninety percent incidence of mammary tumors transmitted by either parent

Mammary tumorigenesis in C3H-A(vy)fB female mice is not due to milk-borne mammary tumor virus but to factors transmitted at conception. Prominent among these is the A(vy) gene which may increase the virulence or transmissibility of a variant of mammary tumor virus vertically transmitted by either parent, or may increase the tumorigenic response of the mammary tissue. These factors together with the influence of hormones of pregnancy resulted in the high incidence observed.     

基于玉米F2：3 群体株型性状 的灰色关联度分析

以玉米F2:3群体株型性状为研究对象,采用灰色关联度分析法对影响玉米叶向值的主要株型性状进行分析。结果表明,穗上二叶挺直长、穗上一叶挺直长和穗上三叶挺直长与叶向值的关联度排在前3位,所有性状对叶向值的关联度顺序是:Lf2(0.9147)Lf1(0.9082)Lf3(0.906)EH(0.8996)L1(0.8856)LW3(0.8855)LW2(0.8854)L3(0.8812)LW1(0.881)L2(0.8772)PH(0.8691)LA2(0.8468)LA1(0.8444)LA3(0.841)。研究结果明确了玉米株型主要农艺性状对叶向值的影响,为株型育种、QTL定位及叶向值遗传机制等基础研究提供依据。     

小麦株高的QTL分析

【目的】研究控制小麦株高的数量性状位点(QTL)。【方法】利用SSR和AFLP分子标记构建连锁图谱,在3种不同试验环境(2003~2004年北京、2004~2005年北京和河南安阳)下分析百农64×京双16组合的218个F2:3株系群体的株高。【结果】构建了由158个分子标记(100个SSR标记和58个AFLP标记)位点组成的遗传连锁图谱,覆盖了除1D连锁群外小麦全基因组的3 114 cM;检测到3个控制株高的QTL,分别位于2B、4D和6A染色体上,贡献率分别为7.3%~11.5%,7.4%~12.9%和5.7%~11.3%。【结论】3个株高QTL位点在不同环境下表现稳定,其紧密连锁的分子标记可用于矮秆、半矮秆小麦的标记辅助育种。