采用聚合酶链式反应-变性梯度凝胶电泳技术分析小熊猫胃肠道菌群的多样性

本试验旨在研究小熊猫胃肠道菌群多样性。采用聚合酶链式反应(PCR)-变性梯度凝胶电泳(DGGE)技术结合条带的克隆测序、聚类分析和主成分分析(PCA)检测小熊猫胃肠道菌群结构及多样性。结果表明:1)PCR-DGGE图谱显示小熊猫胃肠道中有大量菌群,且不同部位的菌群结构存在一定的差异,相邻肠段菌群结构具有一定的相似性。结肠和粪便样品的菌群多样性较高,其次为胃和直肠样品,而空肠和回肠样品菌群多样性较低。2)小熊猫胃肠道菌群PCR-DGGE图谱中测序的条带大多数归为厚壁菌门(Firmicutes)、拟杆菌门(Bacteroides)、变形菌门(Proteobacteria)和疣微菌门(Verrucomicrobia),共性条带主要是未培养拟杆菌门细菌(uncultured Bacteroidetes bacterium)、粪肠球菌(Enterococcus faecalis)、未培养梭状芽孢杆菌(uncultured Clostridium sp.)、乳酸乳球菌(Lactococcus lactis)和食窦魏斯氏菌(Weissella cibaria),其中厚壁菌门为优势菌群;特异性条带主要是丛毛单胞菌(Comamonas sp.)、梭菌属(Clostridium sp.)和Akkermansia。由此可见,小熊猫胃肠道中栖息着大量菌群,且其多样性按照胃肠道由前至后的顺序呈现高-低-高的趋势。     

聚合酶链式反应-变性梯度凝胶电泳技术分析1只死亡野生川金丝猴胃肠道菌群多样性

本试验旨在对1只死亡野生川金丝猴的胃肠道菌群多样性及其克隆测序条带的系统进化树进行分析。取死亡野生川金丝猴胃肠道内容物,进行聚合酶链式反应(PCR)-变性梯度凝胶电泳(DGGE)分析,结合条带的克隆测序、聚类分析和主成分分析(PCA)检测菌群多样性并构建系统进化树。结果显示:1)野生川金丝猴整个胃肠道栖息着大量细菌,且来自胃、小肠的样品聚为一大簇,来自大肠的样品聚为一簇,而来自粪便的样品单独聚为一簇。2)从DGGE图谱上共回收18个条带,细菌种类鉴定主要是5个菌门,分别为变形菌门(Proteobacteria,38.89%)、厚壁菌门(Firmicutes,22.22%)、拟杆菌门(Bacteroidetes,5.56%)、放线菌门(Actinobacteria,5.56%)、疣微菌门(Verrucomicrobia,5.56%)和不可培养菌(uncultured bacterium,22.22%)。其中,变形菌门和厚壁菌门分布于整个胃肠道。3)菌群的系统进化树分析表明,仅有1种不可培养菌与已鉴定的粪肠球菌进化分类相似,而其他不可培养菌与已知的菌种进化分支差异较大,说明在野生川金丝猴的胃肠道中仍有大量的菌群信息未被鉴定。结果提示,本试验测定的1只死亡野生川金丝猴的胃肠道优势菌群为变形菌门,菌群多样性随着胃肠道由前至后的顺序呈现高—低—高的趋势。     

利用16S rRNA测序、PCR-DGGE和qRT-PCR方法分析肉牛瘤胃上皮细菌群落特征

目前对于附着于瘤胃上皮的细菌群落及其功能了解较少,本研究目的是利用16S rRNA测序、PCR-DGGE和qRT-PCR方法比较分析肉牛瘤胃上皮与瘤胃内容物细菌群落的多样性差异.从6个16S rDNA(～1.4 kb)文库中随机选取2785条序列,结果表明3个瘤胃内容物文库与3个瘤胃上皮文库的细菌群落存在差异.以97％的序列相似度进行计算,结果发现瘤胃内容物菌群文库的多样性指数(4.12/4.42/4.88)比瘤胃上皮组织菌群文库的多样性指数(2.90/2.73/3.23)高.厚壁菌门和拟杆菌门分别是瘤胃上皮组织和内容物的优势菌群,纤维杆菌门、浮霉菌门和疣唯菌门仅在瘤胃内容物中存在.通过PCR-DGGE对22头阉牛瘤胃内容物和瘤胃上皮的细菌群落分析,进一步证实瘤胃上皮栖息着一类以厚壁菌为主的独特菌群,这类菌不仅具有消化饲料的作用,还有其他未知功能.     

褪黑素受体MT1和MT2在绵羊胃中的分布及表达

【目的】应用分子生物学技术探究绵羊不同胃室组织褪黑素(MT)特异性膜受体MT1和MT2的分布规律及表达模式,以初步探明绵羊不同胃室组织褪黑素调节胃消化的生物效应机制。【方法】采集绵羊瘤胃背囊、瘤胃腹囊、网胃、瓣胃和皱胃5个组织部位,用ELISA、实时荧光定量PCR、免疫组化和Western blotting方法检测褪黑素特异性膜受体MT1和MT2在绵羊胃组织不同部位的分布规律及表达模式。【结果】ELISA结果显示,绵羊各胃组织中均含有褪黑素,且皱胃中褪黑素含量最高,瓣胃次之,瘤胃背囊、瘤胃腹囊和网胃中均较低。实时荧光定量PCR结果显示,MT1和MT2基因mRNA在皱胃中含量均最高,其次是瘤胃腹囊,在瘤胃背囊和网胃中含量较低。免疫组化结果显示,MT1和MT2蛋白在绵羊各胃组织中均有分布,主要表达于各胃组织的黏膜层,且在皱胃腺体中的分布呈从底部到颈部逐渐增多的趋势。Western blotting结果显示,MT1和MT2蛋白在网胃中表达均最高,瓣胃次之,在瘤胃背囊、瘤胃腹囊和皱胃中表达均较低。【结论】褪黑素在绵羊各胃组织中差异化表达从而发挥多样性生理功能,可能通过与胃组织上特异性受体MT1和MT2结合,通过信号传导系统而调控前胃受食糜刺激后发生反刍生理过程。     

圈养成年非洲狮和幼年非洲狮肠道菌群多样性的比较分析

通过PCR-DGGE技术探讨同一养殖环境中的成年非洲狮和幼年非洲狮肠道菌群多样性。提取总DNA,对16S rDNA的V3区进行变形梯度凝胶电泳,对DGGE图谱进行特异性条带回收和克隆测序,通过BLAST与已知条带对比,结果显示:成年非洲狮肠道内含有梭菌属Clostridium)、毛螺旋菌Lachnospiraceae bacterium)、优杆菌属Anaerovorax)、乳球菌属Lactococcus)、消化链球菌属Peptostreptococcus)和Blautia菌属。而幼年非洲狮肠道内菌群较少且均为共有菌群,如:拟杆菌Bacteroidetes bacterium)、瘤胃菌属(rumen bacterium),UPGMA聚类分析得出,成年非洲狮与幼年非洲狮之间菌群结构相似度较低,仅为34%.以上结果表明,非洲狮成长的不同阶段,菌群结构存在明显的差异。这为野生动物不同阶段微生态制剂的研发提供理论基础。     

褪黑素合成酶在绵羊胃中的表达

为了解绵羊各胃中褪黑素的合成情况。采取绵羊瘤胃背囊、瘤胃腹囊、网胃、瓣胃和皱胃等5个部位,用免疫组化、Western blot、RT-qPCR等方法,探讨褪黑素合成的关键酶AANAT和HIOMT在不同胃的定位和相对表达情况。结果表明,AANAT和HIOMT蛋白在绵羊各胃均有分布,且在各胃的黏膜层呈强阳性表达,其中在皱胃的表达量最高,AANAT在瘤胃背囊和瘤胃腹囊的表达量最低,而HIOMT在瘤胃背囊的表达量最低;AANAT和HIOMT mRNA水平均显示在网胃最高,其中AANAT在瘤胃背囊和瓣胃表达最低,而HIOMT在皱胃中表达最低。综上所述,在绵羊不同胃中均有AANAT和HIOMT的表达,并且AANAT和HIOMT存在表达差异,说明绵羊胃也具有自主合成褪黑素的功能,提示褪黑素可能通过自分泌和旁分泌的作用方式对绵羊胃功能活动进行调控,为进一步研究褪黑素对绵羊胃功能的调控作用机制提供了理论基础。     

不同日粮模式对赤大袋鼠粪样微生物菌群的影响

通过饲喂赤大袋鼠不同模式日粮,运用Mi Seq高通量测序技术研究赤大袋鼠粪样菌群组成及多样性的变化。选取圈养条件下的12只年龄相近、健康状态、营养状况良好的成年赤大袋鼠,随机分成3个处理组,分别饲喂低多汁料低精料(A组)、中等多汁料精料(B组)和高多汁料高精料(C组),各处理组分别收集粪便用于Mi Seq高通量测序。结果显示:各处理组粪样细菌OTU数量相近;各组粪样中所含细菌的种类未出现明显变化(P0.05);在门水平上,各组粪样菌群中优势菌群厚壁菌门(Firmicutes)和拟杆菌门(Bacteroidetes)的相对丰度变化不大,所呈现的变化趋势不显著(P0.05)。在属水平上,未分类瘤胃球菌科(uncultured Ruminococcaceae)和未分类普雷沃氏菌科(uncultured Prevotellaceae),分别为第一和第二位优势菌属,其中处理组二的uncultured Ruminococcaceae显著高于其他2组(P0.05),而uncultured Prevotellaceae显著低于其他2组(P0.05)。结果表明,不同日粮模式对赤大袋鼠粪样菌群不会产生明显影响。与其他哺乳类的食草动物一样,赤大袋鼠粪样中有非常丰富的微生物,厚壁菌门和拟杆菌门为优势菌门。     

采用PCR-DGGE技术分析瘤胃菌群在不同纤维素富集条件下的多样性

本试验旨在采用聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)技术分析瘤胃菌群在不同纤维素富集条件下的多样性。试验采用羧甲基纤维素(CMC)培养基、蛋白胨纤维素(PCS)培养基、J培养基和K培养基分别在37和50℃条件下培养瘤胃内容物,使用PCR-DGGE技术、DGGE图谱共性及特异性条带的克隆和测序、聚类分析和主成分分析(PCA)几种方法分析瘤胃菌群多样性。结果表明:37℃条件下,不同培养基的DGGE图谱差异较大,J培养基和PCS培养基间的相似性系数为0.77;J培养基和CMC培养基间的相似性系数仅为0.76。50℃条件下不同培养基的DGGE图谱相似性较高,J培养基和PCS培养基间的相似性系数为0.78;而CMC培养基和PCS培养基间的相似性系数高达0.84。DGGE图谱中共性条带属于解没食子酸链球菌和解脲芽孢杆菌2个菌属,是瘤胃中的优势菌群;而主要的特异性条带属于解没食子酸链球菌、摩氏假单胞菌、产碱杆菌和未培养毛螺旋菌4个菌属。结果提示,不同纤维素富集培养基和温度对瘤胃菌群的多样性有一定程度上的影响。     

米曲霉培养物与酵母培养物组合对绵羊瘤胃菌群多样性的影响

本试验旨在研究米曲霉培养物(AO)和酵母培养物(YC)组合对绵羊瘤胃发酵及菌群多样性的影响。选用15只装有瘤胃瘘管的绵羊,随机分为5组,即A组(0.4%AO+1%YC)、B组(0.3%AO+1.5%YC)、C组(0.4%AO)、D组(1.5%YC)、E组(对照组),每组3个重复。对每只绵羊在饲喂2 h后采集瘤胃液并利用高通量测序方法测定瘤胃微生物多样性。结果表明:15个处理组共检测到17个细菌门类,拟杆菌门(Bacteroidetes)和厚壁菌门(Firmicutes)为优势菌门;与E组相比,A组节细菌属(Arthrobacter)、根瘤菌(Rhizobium)、Shuttleworthia、Enterorhabdus和Christensenella的细菌丰富度均显著降低(P0.05);B组琥珀酸菌(Succiniclasticum)、新月形单胞菌(Selenomonas)、Papillibacter和不可培养的梭菌属的丰富度显著升高(P0.05),但节细菌属(Arthrobacter)、根瘤菌(Rhizobium)、鞘氨醇单胞菌(Sphingomonas)、假单胞菌(Pseudomonas)、Christensenella和Shuttleworthia的丰富度显著降低(P0.05)。上述结果表明,添加AO和YC能增加瘤胃中拟杆菌门(Bacteroidetes)和纤维杆菌门(Fibrobacteres)的相对丰度,减少变形菌门(Proteobacteria)的相对丰度,增加月形单胞菌属(Selenomonas)和梭菌属(Fusobacterium)等有益菌的数量,降低鞘氨醇单胞菌(Sphingomonas)、假单胞菌(Pseudomonas)的数量。     

放牧绵羊消化器官的发育性变化

为了研究羔羊消化器官的发育性变化,以0～56日龄甘肃高山细毛羊放牧绵羊为研究对象,采用大体解剖学方法测定了放牧条件下0、3、7、14、21、28、42、56日龄羔羊瘤胃、网胃、瓣胃、皱胃、前胃、总胃重量、容积以及各胃室内容物重量,胰腺、肝脏重量,十二指肠、空肠、回肠重量及长度的变化情况。结果表明,随羔羊日龄增大各消化器官和消化腺绝对重量都在增大;瘤胃重量和容积随羔羊日龄增大而显著增加(P<0.05),7日龄开始瘤胃内容物及瓣胃重量、网胃容积显著增大;28日龄开始小肠总长基本维持恒定,大约为体长的25倍。羔羊食入牧草可明显刺激瘤胃的发育。     

电感耦合等离子-质谱法测定饲料中钠、镁、铬、锰、铁、铜、锌、砷、硒、镉和铅

应用电感耦合等离子-质谱技术(ICP-MS),建立饲料中钠、镁、铬、锰、铁、铜、锌、砷、硒、镉和铅等元素的测定方法。对饲料样品的前处理方法、仪器工作参数和11种元素标准曲线进行优化;并以加标回收、分析方法比对和重复测试说明方法的准确性和精密性。方法在0～1 000 ng/ml范围内线性良好,仪器检出限为0.557 7～5.072 ng/ml,具有良好的精密度,其回收率在88.1%～104.4%之间,相对标准偏差小于5.0%。同时与原子吸收和原子荧光方法进行比对,测定结果相近。所建立的方法简单、快速,可替代原子吸收和原子荧光方法测定饲料中的11种金属元素,为饲料的质量控制提供理想的元素分析方法。     

液相色谱-串联质谱法测定动物尿液中11种β-受体激动剂残留量的不确定度评估

采用液相色谱-串联质谱法测定动物尿液中11种β-受体激动剂残留量,对标准溶液、体积、质谱峰面积、浓缩过程及回收率等测定不确定度因素进行了分析,通过评定各不确定度分量及标准不确定度,得出11种β-受体激动剂的扩展不确定度在0.7 ～ 1.1 ng/mL范围内.由各因素对合成不确定度的贡献比分析可知,影响较大的因素为试验回收率及标准溶液浓度.     

Supplementation of broodmares with copper, zinc, iron, manganese, cobalt, iodine, and selenium

In experiment 1, 6 pregnant mares received a concentrate that contained a trace mineral premix that provided 14.3 mg Cu, 40 mg Zn, 28 mg Fe, 28 mg Mn, 0.08 mg Co, 0.16 mg I, and 0.16 mg Se/kg concentrate (group A). Seven mares received the same concentrate plus 502 mg Zn and 127 mg Cu once daily (group B). No differences (P > .05) in foal growth data, or Cu, Zn, and Fe concentrations of mare milk, mare serum, or foal serum were observed. In experiment 2, 6 pregnant mares received the same concentrate as group A (group C), and 8 mares received the same concentrate fortified with 4× the trace mineral premix (group D). Group C mares had higher serum Zn concentration at 1 day (P < 0.01) and 56 days (P < 0.04). Group C mares had higher milk Fe concentration at 28 days (P < .01), and group D mares had higher milk Cu concentration at 56 days (P < .01). Group C foals had higher serum Cu concentration at 14 days (P < .03). The results from this study provide no evidence to indicate that supplementing late gestating and lactating mares with higher dietary trace mineral levels than those recommended currently by NRC has any influence on foal growth and development, or on the Cu, Zn, and Fe concentrations of the mare milk, mare serum, or foal serum.     

文山黄牛的现状与保种措施

文章阐述了文山黄牛的品种特性、现状和保种措施。文山牛保种可采用原产地活体保种,迁地活体保种和现代生物技术保种等多种方式。文山牛体型较大,性情温顺,产肉性能好、活动敏捷、结构紧凑、肌肉强健、肉品质优良、耐粗饲、适应性广、繁殖力和抗病力均较强等特点。文山牛是云南省一个地方良种,种质资源保护刻不容缓。     

Comparisons of Angus, Charolais, Galloway, Hereford, Longhorn, Nellore, Piedmontese, Salers, and Shorthorn breeds for weight, weight adjusted for condition score, height, and condition score of cows

Breed differences for weight (CW), height (CH), and condition score (CS) were estimated from records (n = 12,188) of 2- to 6-yr-old cows (n = 744) from Cycle IV of the U.S. Meat Animal Research Center's Germplasm Evaluation (GPE) Program. Cows were produced from mating Angus and Hereford dams to Angus, Hereford, Charolais, Shorthorn, Galloway, Longhorn, Nellore, Piedmontese, and Salers sires. Samples of Angus and Hereford sires were 1) reference sires born from 1962 through 1970 and 2) 1980s sires born in 1980 through 1987. The mixed model included cow age, season of measurement and their interactions, year of birth, pregnancy-lactation code (PL), and breedgroup as fixed effects for CW and CS. Analyses of weight adjusted for condition score included CS as a linear covariate. The model for CH excluded PL. Random effects were additive genetic and permanent environmental effects associated with the cow. Differences among breed groups were significant (P < 0.05) for all traits and were maintained through maturity with few interchanges in ranking. The order of F1 cows for weight was as follows: Charolais (506 to 635 kg for different ages), Shorthorn and Salers, reciprocal Hereford-Angus (HA) with 1980s sires, Nellore, HA with reference sires, Galloway, Piedmontese, and Longhorn (412 to 525 kg for different ages). Order for height was as follows: Nellore (136 to 140 cm), Charolais, Shorthorn, Salers, HA with 1980s sires, Piedmontese, Longhorn, Galloway and HA with reference sires (126 to 128 cm). Hereford and Angus cows with reference sires were generally lighter than those with 1980s sires. In general, breed differences for height followed those for weight except that F1 Nellore cows were tallest, which may in part be due to Bos taurus-Bos indicus heterosis for size.     

Concentrations of strontium,barium, cadmium,copper, zinc,manganese, chromium,antimony, selenium,and lead in the liver and kidneys of dogs according to age,gender, and the occurrence of chronic kidney disease

This study was conducted to measure the concentrations of strontium (Sr), barium (Ba), cadmium (Cd), copper (Cu), zinc (Zn), manganese (Mn), chromium (Cr), antimony (Sb), selenium (Se), and lead (Pb) in canine liver, renal cortex, and renal medulla, and the association of these concentrations with age, gender, and occurrence of chronic kidney disease (CKD). Tissues from 50 dogs were analyzed using inductively coupled plasma mass spectrometry. Cu, Zn, and Mn levels were highest in the liver followed by the renal cortex and renal medulla. The highest Sr, Cd, and Se concentrations were measured in the renal cortex while lower levels were found in the renal medulla and liver. Female dogs had higher tissue concentrations of Sr (liver and renal medulla), Cd (liver), Zn (liver and renal cortex), Cr (liver, renal cortex, and renal medulla), and Pb (liver) than male animals. Except for Mn and Sb, age-dependent variations were observed for all element concentrations in the canine tissues. Hepatic Cd and Cr concentrations were higher in dogs with CKD. In conclusion, the present results provide new knowledge about the storage of specific elements in canine liver and kidneys, and can be considered important reference data for diagnostic methods and further investigations.     

枇杷种质资源创新利用研究进展

枇杷是原产于中国的亚热带果树,是一种药食同源的保健水果,其栽培历史悠久。我国幅员辽阔,生态环境多样,孕育了世界上最多的枇杷种质资源。本文综述了我国枇杷属植物种质资源的收集与保存、种质交流、种质创新与利用的研究现状、问题分析;对未来发展提出意见,要努力创制“种源惟一,节肥、节水,省工、省力、省药”的“一源两节三省”品种与配套栽培技术,精准保护知识产权。对种源的知识产权保护要织密物防、技防的网络,诉案须有保护对象唯一的技术身份数据佐证,独具排他性。综述,本研究为枇杷种质资源的发展创制和产业发展提供决策参考。