Effect of energy and protein levels on performance,egg quality,and nutrient digestibility of laying pigeons

A total of 3,240 female Taisheng pigeons at 40 wk age were fed 9 diets containing 3 ME levels (2,630, 2,770, and 2,940 kcal/kg) and 3 CP levels (14.0, 15.0, and 16.0%) in a factorial arrangement. These diets were fed to investigate the effects of ME and CP on performance, egg quality, and nutrient digestibility. Female pigeons were housed under the same managerial conditions and randomly assigned into 9 treatments (6 replicates of 60 birds each). Two female–female paired pigeons housed in one cage were under a 16L:8D lighting cycle. Feed in pellet form and water were provided for ad libitum consumption. The study lasted 12 wk. As dietary ME level increased from 2,630 to 2,940 kcal/kg, BW, egg production, and apparent DM, crude fat (CF), and phosphorus (i.e., P) digestibilities increased (P < 0.05), feed intake decreased (P < 0.05), and feed conversion efficiency increased (P < 0.05). Increasing the level of dietary protein from 14 to 16% resulted in an increased (P < 0.05) BW, shell percentage, length of the major axis, and DM digestibility. Therefore, dietary ME had a greater influence on the performance of Taisheng laying pigeons than did dietary protein.     

Cloning and Protein Structure Analysis of Hypoxia Inducible Factor-1α Gene in Yak

In this study,hypoxia inducible factor-1α(HIF-1α) gene was cloned from yak spleen by RT-PCR,and it was divided into two sections for amplification.The sequence and protein structure were analyzed using related bioinformatics tools.The length of the coding region was 2 472 bp,which encoded 823 amino acids.Its molecule mass was 92.13 ku,and PI was 5.09.It displayed as a hydrophilic protein,whose secondary structure was mainly composed of random coil and α-helix.It had 69 phosphorylation sites and 4 N-glycosylation sites.Phylogenetic tree displayed that Maiwa yak,Bos grunniens,Bos mutus and Bos taurus gathered into one cluster.Maiwa yak HIF-1α gene was successfully cloned in this study,it provided a viable reference for further study of genetic characteristics of HIF-1α.     

重组减蛋综合征病毒KnobS干酪乳杆菌的构建与表达

以干酪乳杆菌为传递载体,以开发食品级安全的减蛋综合征病毒疫苗为目标,构建了一个温度敏感型自杀型质粒系统p ORZP-UKD。将该质粒电转化到干酪乳杆菌L.casei中,经过2次升温处理和5-氟尿嘧啶抗性筛选,挑选阳性克隆,采用PCR和SDS-PAGE方法进行鉴定。KnobS基因整合到干酪乳酸杆菌基因组内,并实现融合蛋白KnobS的分泌表达。表明得到了一株具有无任何选择性标记、携带有KnobS表达盒元件的基因组整合的重组干酪乳酸杆菌KnobSΔupp L.casei,且整合的外源基因能够随着细菌的复制而进行表达,为减蛋综合征病毒免疫保护性抗原KnobS疫苗的进一步研制提供了试验数据。     

玉米青贮与花生秧配比对奶牛瘤胃中花生秧降解特性的影响

本试验旨在研究玉米青贮与花生秧配比对奶牛瘤胃中花生秧降解特性的影响。选择4头体重、生理状态、生产性能相近,装有永久瘤胃瘘管的中国荷斯坦奶牛,分别饲喂含有玉米青贮与花生秧不同配比的全混合日粮(TMR),3种TMR中玉米青贮与花生秧的干物质(DM)配比分别为3.9∶1.0(A组)、1.2∶1.0(B组)、0.4∶1.0(C组)。试验分3期进行,依次进行A、B、C组试验。每期预试15 d,采样期4 d;共57 d。采用尼龙袋瘤胃降解技术测定花生秧在奶牛瘤胃中DM、粗蛋白质(CP)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)的72 h瘤胃降解率,并求得目标养分的动态降解参数及有效降解率。结果表明:1)花生秧的DM在瘤胃中有效降解率为56.49%~59.62%,CP为40.45%~47.36%,NDF为33.26%~35.20%,ADF为36.31%~37.45%。2)B组DM的有效降解率显著高于C组(P0.05),极显著高于A组(P0.01);B、C组的CP有效降解率显著高于A组(P0.05)。3)B、C组的NDF快速降解部分含量显著高于A组(P0.05);3种TMR对花生秧粗NDF和ADF有效降解率无显著影响(P0.05)。由此可见,花生秧具有较高的饲用价值。本试验条件下,玉米青贮与花生秧DM配比为1.2∶1.0时,可有效提高花生秧DM和CP的瘤胃降解率。     

冰淇淋混合料液的老化

阐述了冰淇淋混合料液老化过程的条件控制及混合料在老化过程中发生的主要变化。经过老化过程,混合料液的黏度显著增加,有助于凝冻过程中的搅打起泡,使冰淇淋产品的质构更加细腻,抗融性和贮藏稳定性更好。     

抗凋亡融合蛋白PTD-Bcl-xL原核表达载体的构建及表达纯化

人工抗凋亡蛋白PTD-Bcl-x L能保护多种因素引起的细胞异常凋亡,为了获得高纯度Bcl-x L与PTD(Protein transduction domains)的融合蛋白,首先采用TRIzol法提取SD大鼠肝脏总RNA,将RNA反转录为c DNA,设计引物以c DNA为模板,PCR扩增Bcl-x L基因,构建p UM19-T-Bcl-x L质粒,并对质粒双酶切鉴定和测序鉴定;其次设计包含PTD序列的Bcl-x L引物,以测序正确的p UM19-T-Bcl-x L质粒为模板,PCR扩增PTD-Bcl-x L序列,将扩增序列克隆入p ET28a载体,构建PTD-Bcl-x L蛋白的原核表达质粒p ET28a-PTD-Bcl-x L,并对p ET28a-PTD-Bcl-x L载体双酶切鉴定和测序鉴定;将p ET28a-PTD-Bcl-x L重组质粒转化大肠杆菌BL21(DE3),用IPTG诱导表达,并对IPTG诱导融合蛋白表达的浓度和诱导时间进行了优化;SDS-PAGE分析表达蛋白的可溶性情况,在变性条件下用Ni-NTA琼脂纯化融合蛋白;最后用SDS-PAGE、Western Blot及质谱对融合蛋白进行鉴定。结果表明:双酶切p UM19-T-Bcl-x L质粒出现约774 bp大小条带,p UM19-T-Bcl-x L质粒测序结果与NCBI数据库比对序列一致,表明成功构建p UM19-T-Bcl-x L质粒;双酶切p ET28a-PTD-Bcl-x L质粒出现约744 bp大小条带,p ET28a-PTD-Bcl-x L质粒测序结果与预期序列一致,表明成功构建了p ET28a-PTD-Bcl-x L原核表达载体;在IPTG诱导下p ET28a-Bcl-x L重组质粒在大肠杆菌BL21(DE3)中表达出36 k Da大小蛋白,最优IPTG诱导浓度为0.1 mmol/L,最佳IPTG诱导时间为6 h;SDS-PAGE电泳显示融合蛋白主要出现在菌液超声后的沉淀里,以包涵体形式表达,经Ni-NTA琼脂纯化获得了高纯度的融合蛋白;Western Blot和质谱鉴定证明IPTG诱导表达蛋白和纯化的融合蛋白为PTD-Bcl-x L蛋白。纯化得到了PTD-Bc L-x L融合蛋白,推进了PTD-Bcl-x L蛋白在猪、牛等家畜精液冷冻保存的应用进程。     

陆地棉ZF-HD蛋白的全基因组分析

ZF-HD(Zinc finger-homeodomain)蛋白属于同源异型盒蛋白家族,在动植物发育过程中起重要的作用。利用生物信息学的手段,研究陆地棉标准系TM-1基因组中ZF-HD蛋白的数目、亚细胞定位、染色体分布、基序、进化关系和组织表达情况。TM-1中共有35个Gh ZHD蛋白成员,且大部分成员定位到细胞核内;分布在20条染色体和2条Scaffold上,且具有11对直系同源基因;进化树分析表明,TM-1基因组中的ZF-HD蛋白大致分为6个小组,每个小组成员间具有类似的基序类型和排列顺序;大部分Gh ZHD基因在胚珠和纤维组织中表达,还有部分基因在根、茎、花、蕾和分生区中表达,在叶和愈伤组织中表达的基因最少。     

红素氧还蛋白研究进展

自然界中大多数的红素氧还蛋白(rubredoxin)集中来自严格厌氧菌,包括细菌、古菌和少数微需氧细菌,而植物中该类蛋白相对较少,它的功能主要表现在作为辅因子或电子供体参与多个生化途径。也有研究显示,无论是植物中还是微生物中的红素氧还蛋白基因在协助生物抵御氧化胁迫方面均发挥着重要的作用。本文全面介绍自然界中的红素氧还蛋白基因的分布、结构以及在微生物、植物中所发挥的作用等,希望能为今后的进一步研究提供参考。     

Analysis of Inter-Individual Bacterial Variation in Gut of Cicada Meimuna mongolica (Hemiptera: Cicadidae)

Intestinal bacterial community plays a crucial role in the nutrition, development, survival, and reproduction of insects. When compared with other insects with piercing-sucking mouthparts, the habitats of cicada nymphs and adults are totally different. However, little is known about the differences in the gut bacterial communities in the nymphs and adults within any cicada species. The diversity of bacteria in the gut of nymphs and adults of both genders of Meimuna mongolica (Distant) was studied using the denaturing gradient gel electrophoresis (DGGE) method. Few inter-individual variations among gut microbiota were observed, suggesting that M. mongolica typically harbors a limited and consistent suite of bacterial species. Bacteria in the genera Pseudomonas and Enterobacter were the predominant components of the gut microflora of M. mongolica at all life stages. Bacteria of Pantoea, Streptococcus, and Uruburuella were also widespread in the cicada samples but at relatively lower concentrations. The relative stability and similarity of the PCR-DGGE patterns indicate that all individuals of this cicada species harbor a characteristic bacterial community which is independent from developmental stages and genders. Related endosymbionts that could be harbored in bacteromes of cicadas were not detected in any gut samples, which could be related to the cicada species and the distribution of these endosymbionts in the cicada cavity, or due to some of the possible limitations of PCR-DGGE community profiling. It is worthwhile to further address if related cicada endosymbiont clades distribute in the alimentary canals and other internal organs through diagnostic PCR using group-specific primer sets.     

马乳脂肪球膜蛋白组鉴定及潜在功能分析

试验旨在研究马乳脂肪球膜（milk fat globule membrane，MFGM）蛋白组成及潜在的生物学功能。选取12匹5岁左右、平均体重为450~500 kg的健康纯血母马作为试验动物，主要饲喂干牧草，所有马匹饲养和管理条件均相同。将12份样品以每组4份进行混合，分离提取产后第60天马乳中MFGM蛋白，进行高分辨质谱仪鉴定和生物信息学分析。结果显示，马MFGM组分中共鉴定出310种表达蛋白，这些蛋白主要参与的生物过程为生物调节、刺激应答、定位、多细胞生物过程、运输、信号、细胞通讯、发育过程、细胞分化和免疫系统过程等；细胞成分主要为胞外区域、膜、囊泡、核仁和线粒体等；分子功能主要为催化活性、蛋白质结合、碳水化合物衍生物结合和小分子结合等。KEGG通路分析表明，MFGM蛋白主要参与血小板活化通路、内吞、脂肪酸生物合成和Ras信号通路等。马乳MFGM蛋白的蛋白质互作网络分析图中共包含215种蛋白质。本研究结果揭示了马乳MFGM蛋白质组的复杂性，为解析其营养和生物学功能提供了科学数据。