多年生黑麦草高频再生体系的建立及优化

从外植体预处理方式、基本培养基、激素浓度等方面着手,对多年生黑麦草愈伤组织诱导、继代、不定芽分化及再生过程中的影响因素进行了研究,提高了再生频率。结果如下：切取胚端半粒种子,经75%乙醇处理1min,0.1%HgCl处理15min,在经无菌水清洗4～6次后接种方式较好;愈伤组织诱导培养基以MS＋2,4—D 8.0 mg/L（或另添加甘露醇25 g/L）为佳;愈伤组织接种于MS＋2,4—D 8.0mg/L＋甘露醇25 g/L上进行1～2次继代后于NB＋6—BA2.0 mg/L上进行分化;不定芽转接至MS＋6—BA2.0 mg/L上进行扩繁或于1/2MS＋NAA0.5mg/L＋IAA0.5mg/L上进行生根。     

Has the optimum time for faecal nematode egg count reduction testing in sheep in New Zealand changed?

Abstract

AIM: To determine what, if any, changes have taken place in the optimum time, for undertaking faecal egg count reduction tests (FECRT) in sheep in New Zealand.

METHODS: A comparison was made between the numbers and types of nematode genera adequately represented for testing purposes (faecal nematode egg count (FEC) of >50 epg) in initial FECRT case submissions to a veterinary laboratory in New Zealand, during two 4-year periods, in 1992–1995 and 2006–2009.

RESULTS: Although there were some minor differences between them, the seasonal patterns of occurrence remained basically the same for all parasite genera in both datasets, with their individual peak periods of representation occurring during February to May in all instances. Not surprisingly, this period of maximum seasonal occurrence for each parasite genus also coincided with those months of the year when the greatest numbers of worm genera were adequately represented for faecal nematode egg count reduction (FECR) testing.

CONCLUSIONS: The results of this study indicate that the optimum time for conducting FECRT in sheep in New Zealand continues to be during the late summer-autumn months of February to May. However, they also reaffirmed that even during this optimal period there are still likely to be many occasions when relatively few nematode genera may be sufficiently well represented for satisfactory FECR testing. Accordingly, veterinary practitioners ought to be aware that, in order to obtain a complete picture of the resistance status of all worm genera on a particular property, such testing may need to be carried out on more than one occasion.     

云南半细毛羊毛囊干细胞生物学特性分析

为研究云南半细毛羊毛囊干细胞（hair follicle stem cells,HFSCs）的生物学特性,采用组织块法分离培养云南半细毛羊HFSCs,并对其细胞形态、生长动力学、冷冻与复苏、染色体核型等生物学特性进行分析.结果表明：HFSCs为贴壁生长,体积小,核质比高,呈典型的铺路石状,在显微镜下折光性强、胞体透亮.细胞生长曲线为“S”型.冻存前细胞活率98.2％,复苏后细胞活率96.4％.染色体中正常二倍体数目2n=54,其中,长染色体中有3对为中着丝点染色体,23对为端着丝点染色体,X染色体为最大的近端着丝点染色体,Y染色体为最小的亚中着丝点染色体.所得细胞呈现典型的HFSCs特征,细胞活性好,细胞系为稳定的二倍体细胞系.     

MTT比色法在传染性法氏囊病病毒分离中的应用

应用MTT比色法检测了病料中传染性法氏囊病病毒(IBDV)在细胞培养物中的增殖情况，并对病料中加入法氏囊提取液、鸡胚浸出液2种成分对病毒增殖的影响作了比较。结果表明，MTT比色法简便、快速、可靠，能很好地反映病毒在细胞培养物中的增殖情况。     

"蚕为龙精"蕴含中华农耕社会"集体意识"的阐释

杜尔克姆认为集体意识通过社会事实表现,是一个民族重要的心理现象,而且不会随着个体意愿的改变而消失。在神圣社会中,图腾和神话是构成原始社会成员集体意识的重要内涵。以"蚕为龙精"为切入点,通过对龙、蚕共有的时令特征、玉蚕图腾包含的礼治集体意识,以及"嫘祖始蚕"神话蕴含的王权思想集体意识的分析,阐释中华农耕社会中集体意识使蚕丝文化得以瓜瓞绵绵。     

影响非禽源外源病毒检验的主要因素

本文以《中华人民共和国兽药典》2015版三部非禽源外源病毒检验方法为依据,总结了检测过程中细胞状态、样品处理、接种与继代培养、荧光抗体检查等对外源病毒检验的影响,为企业提高外源病毒检验的准确度和检出率提供参考。     

饲料中添加白术多糖对林下养殖绿壳蛋鸡生产性能与蛋品质的影响

为研究饲料中添加白术多糖对林下养殖绿壳蛋鸡生产性能与蛋品质的影响,试验选用28周龄产蛋的东乡黑羽绿壳蛋鸡540只,随机分为3组,每组3个重复,每个重复60只,1组为对照组饲喂基础日粮,试验2、3组分别在基础日粮中添加2.5%、5.0%白术多糖,预饲期7 d,试验期28 d。在试验期间,测定林下养殖绿壳蛋鸡生产性能和蛋品质。结果表明:(1)试验3组产蛋率和平均蛋重分别较对照组提高7.33%、6.26%(P <0.05);试验3组料蛋比较对照组降低12.64%(P <0.05);试验2、3组的商品合格率、日产蛋量、日均采食量均高于1组,差异不显著(P> 0.05)。(2)试验3组蛋质量、哈夫单位、蛋壳厚度分别较对照组提高5.63%、3.02%、6.12%(P <0.05);试验2、3组的蛋形指数、蛋黄颜色、蛋黄比例均高于1组,差异不显著(P> 0.05)。综上所述,在基础饲料中添加5.0%白术多糖可以提高林下养殖绿壳蛋鸡生产性能与蛋品质。     

Establishment of an in vitro culture model to study milk production and the blood–milk barrier with bovine mammary epithelial cells

This study attempted to establish a culture model to recreate the milk production pathway in bovine mammary epithelial cells (BMECs). BMECs were isolated from Holstein cows (nonlactating, nonpregnant, and parous) and were stored by cryopreservation. To separate the apical and basolateral compartments, BMECs were cultured on a cell culture insert with a collagen gel in the presence of bovine pituitary extract and dexamethasone to induce milk production and tight junction (TJ) formation. The culture model showed the secretion of the major milk components, such as β‐casein, lactose, and triglyceride, and formed less‐permeable TJs in BMECs. Moreover, the TJs were distinctly separated from the apical and basolateral membranes. Glucose transporter‐1, which transports glucose into the cytoplasm through the basolateral membrane, localized in the lateral membrane of BMECs. Toll‐like receptor‐4, which binds to lipopolysaccharide in the alveolar lumen in mastitis, localized in the apical membrane. Beta‐casein was mainly localized near the Golgi apparatus and the apical membrane. Moreover, milk components were almost secreted into the upper chamber of the cell culture insert. These findings indicate that this model has clear cell polarity as well as in vivo and is effective to study of milk production and the blood–milk barrier in lactating BMECs.