绵羊卵泡发育过程中关键信号通路研究进展

卵泡从原始卵泡发育为成熟卵泡，直至排卵、黄体发育等过程都受到精密的调控，产生大量的优势卵泡是绵羊产多羔及实现快速扩繁的关键因素。研究发现，相关信号通路和转录因子通过影响绵羊卵泡中卵母细胞、颗粒细胞的生长，进而调控卵泡的发育成熟，对这些信号通路进行深入了解，有助于探索卵泡发育的调控机制，早日实现绵羊高效繁育。Notch是卵泡发育过程中发挥重要作用的高度保守信号通路，PI3K/AKT/mTOR信号通路各成员都是广泛存在于细胞内的信号转导分子，在卵泡发育早期发挥了主要作用，还有间隙连接（gap junction，GJ）和跨带突触（transzonal projections，TZPs）等物理连接方式，在细胞间的交流通讯起到重要作用。作者详细介绍了Notch信号通路、PI3K/AKT/mTOR信号通路、间隙连接及跨带突触的结构功能在绵羊卵泡发育中的调控作用，为进一步探明绵羊卵泡发育的调控机制提供参考。     

基于工作过程CAD/CAM工程技术应用课程教学改革实践

针对CAD/CAM工程技术应用的课程体系、理论课程教学内容、教学方法和实验课程教学进行了改革,成功地建立了CAD/CAM工程技术应用课程体系,取得了良好的教学效果。     

大豆胞囊线虫主效抗病基因Rhg4(GmSHMT)的CAPS/dCAPS标记开发和利用

大豆胞囊线虫(soybean cyst nematode,SCN)严重危害世界大豆生产,Rhg4(resistance to Heterodera glycines 4)是控制大豆SCN抗性的2个主效位点之一。本研究针对Rhg4(Gm SHMT)上的2个单核苷酸多态性(single nucleotide polymorphisms,SNP)位点开发了快速、经济、简便易行的CAPS(Rhg4-389)和d CAPS标记(Rhg4-1165),并用开发的2个标记鉴定了以大豆胞囊线虫应用核心种质为主的193份代表性抗感种质。结果表明,Rhg4-389和Rhg4-1165位点间存在显著连锁不平衡(P=0.0001,r2=0.87),可形成4种单倍型。Rhg4-389-G/Rhg4-1165-T和Rhg4-389-C/Rhg4-1165-A为优势单倍型,稀有单倍型Rhg4-389-G/Rhg4-1165-A和Rhg4-389-C/Rhg4-1165-T是在中国抗源中新发现的单倍型。结合193份种质对SCN 3号小种抗性鉴定分析发现,Rhg4-389-G和Rhg4-1165-T主要存在于抗病种质,它们形成的单倍型对抗病种质鉴定效率可达94.1%。本研究开发了可用于辅助大豆SCN抗性鉴定且方便育种家利用的CAPS/d CAPS标记,且用其摸清了应用核心种质等重要抗源在Rhg4位点的"本底",为育种家有效利用这些优异抗源提供了重要信息。     

Comparison of dietary essential amino acid requirements determined from group‐housed versus individually‐housed juvenile bluegill,Lepomis macrochirus

Two 60‐day experiments were conducted sequentially to determine (i) lysine requirement of juvenile bluegill, Lepomis macrochirus based on the dose–response method, (ii) requirements for other essential amino acids (EAAs) using whole‐body amino acid profile and (iii) whether differences in growth rates of group‐housed versus individually‐housed bluegills lead to different lysine requirement levels because of the presence and absence, respectively, of social hierarchies. Seven, semi‐purified, experimental diets (isonitrogenous, isocaloric) were prepared to contain graded levels of digestible lysine (10–31 g kg⁻¹). Experiment‐1 involved group‐housed bluegills (approximately 27 g, n = 10 fish/chamber, 4 chambers/diet) whereas experiment‐2 involved individually‐housed bluegills (approximately 30 g, n = 1 fish/chamber, 14 chambers/diet). Fish were fed twice daily to apparent satiation. Bluegill growth responses in both experiments generally improved (P < 0.05, anova ) with increasing dietary lysine levels from 10 to 16 g kg⁻¹, and then levelled off with further increase in lysine level (P > 0.05). Optimal dietary lysine level (digestible basis) was estimated to be 15 g kg⁻¹ based on broken‐line regression analyses of relative growth rate and feed conversion ratio with no differences being observed between the two rearing methods. Determined dietary requirement levels for other EAAs ranged from 2.4 g kg⁻¹ (tryptophan) to 15.3 g kg⁻¹ (leucine).     

Single and Interactive Effects of Temperature and Light Quality on Four Canola Cultivars

Combined effects of temperature and light quality on plants have received little attention. We investigated the single and interactive effects of temperature and light quality on growth and physiological characteristics of four canola (Brassica napus) cultivars – Clearfield 46A76 (cv₁), Clearfield 45H72 (cv₂), Roundup Ready 45H24 (cv₃) and Roundup Ready 45H21 (cv₄). Plants were grown under lower (24°/20 °C) and higher (30°/26 °C) temperature regimes at low red/far‐red (R/FR), normal R/FR and high R/FR light ratios in environment‐controlled growth chambers (16 h light/8 h dark). Higher temperature reduced stem height and diameter; leaf number and area; dry matter of all plant parts; and specific leaf weight, but increased leaf area ratio; and chlorophyll (Chl) fluorescence (Y). Low R/FR increased stem height; Y; and ethylene, but decreased stem diameter; F_v/F_m; Chl a; Chl b; and carotenoids. Among cultivars, plants from cv₄ were tallest with thickest stems and greatest dry matter. None of the main factors affected gas exchange. Higher temperature at high R/FR caused cv₃ to be shortest, whereas lower temperature at low R/FR caused cv₄ to be tallest. We conclude that heat and other stress factors will adversely affect sensitive crops, but tolerant genotypes should perform well under future climate.     

An experimental study of charcoal degradation in a boreal forest

Degradation rates of pyrogenic carbon (PyC) under natural environmental conditions are largely unknown. Here we present results from a field experiment monitoring the change in mass, C- and N concentrations of a variety of charcoal types in a Norwegian boreal forest over a period of 20 months. The charcoal types represent different feedstock tree species, production temperature regimes, and placements in the forest, i.e. above ground, in the humus layer or in contact with the mineral subsoil. The types of charcoal had different initial C concentrations mainly depending on their production temperature. Nevertheless, all types of charcoal at all placements in the forest showed an initial drop in their C concentrations, which subsequently rose back to reach near initial values in part of the charcoal types. In part of the charcoal types, N concentrations decreased throughout the experiment, exhibiting considerable variation among feedstock species, production temperature regime, and placements in the forest. C/N ratios rose especially in charcoal made from wood of Scots pine (Pinus sylvestris L.), and charcoal that had been stored in contact with the mineral subsoil showed the most rapid mass gain. Our results confirm the important influence of production temperature and feedstock type on the degradation of charcoal, but they also show that microbial activity and environmental conditions play significant roles in charcoal degradation and thus for the fate of pyrogenic carbon under natural conditions.     

厄贝沙坦及其复方制剂中痕量杂质N-亚硝基-N-甲基-4-氨基丁酸残留方法学研究

采用超高效液相色谱-三重四级杆质谱(UPLC-MS/MS)建立厄贝沙坦及其复方制剂中N-亚硝基-N-甲基-4-氨基丁酸(NMBA)的测定方法。采用Waters ACQUITY UPLC○RHSS T3色谱柱进行分离,以0.005 mol/L甲酸铵(用甲酸调pH值至3.0)为流动相A,甲醇为流动相B,梯度洗脱,质谱检测器,流速为0.3 mL/min。结果显示NMBA的线性范围为0.156 6~3.132 6 ng/mL,相关系数r>0.99,方法检出限浓度为0.047 0 ng/mL(相当于样品浓度0.01μg/g),定量限浓度为0.156 6 ng/mL(相当于样品浓度0.03μg/g),样品加标回收率在80%~130%。说明该方法可以快速、简便、灵敏、准确地测定厄贝沙坦及其复方制剂中NMBA含量。     

伪狂犬病病毒在NF-κB家族p65基因敲除细胞系的复制规律研究

试验旨在研究伪狂犬病病毒(PRV)在NF-κB家族p65基因敲除细胞系中的复制规律。利用慢病毒介导的CRISPR/Cas9基因定点修饰技术构建猪肺泡巨噬细胞(3D4/21)p65基因稳定敲除细胞系。通过构建p65-sgRNA重组质粒,转染至HEK293T/17细胞,收取慢病毒,感染3D4/21细胞后利用嘌呤霉素筛选获得多克隆细胞系,T7核酸酶检测敲除效率,再通过有限稀释法获得3D4/21-p65^-/-的稳定细胞系。CCK-8试剂盒检测3D4/21细胞中敲除p65基因后对细胞增殖的影响;流式细胞术检测PRV-GFP感染3D4/21及3D4/21-p65^-/-细胞后病毒增殖的差异;实时定量PCR检测PRV感染3D4/21及3D4/21-p65^-/-细胞后PRV gB、TK基因mRNA表达水平及PRV感染细胞诱导的IL-1β和IL-6基因mRNA水平表达的变化;Western blotting检测PRV-QXX感染3D4/21及3D4/21-p65^-/-细胞后PRV gB、gE蛋白的表达;滴度测定检测PRV-QXX感染3D4/21及3D4/21-p65^-/-细胞后子代病毒滴度。结果表明,sgRNA2和sgRNA3的基因编辑效率较高,对其进行克隆化培养进而获得敲除p65基因的稳定表达细胞系;CCK-8试剂盒检测细胞活力表明,p65基因敲除对细胞活力无影响;流式细胞仪检测表明,同一时间点PRV-GFP在3D4/21-p65^-/-中的增殖显著高于对照细胞;实时荧光定量PCR表明在3D4/21细胞中敲除p65基因促进了PRV gB、TK基因的mRNA表达水平,而抑制了IL-1β、IL-6基因的mRNA表达;Western blotting结果表明,在3D4/21细胞中敲除p65基因促进了PRV gB、gE蛋白的表达;滴度测定结果表明,同一时间点PRV-QXX在3D4/21-p65^-/-细胞中子代病毒的复制显著高于对照细胞。以上结果均表明,p65基因敲除可促进PRV在3D4/21细胞中复制。