Ⅰ型鸭肝炎病毒(MY株)活疫苗毒种的纯粹及生产条件探索

将Ⅰ型鸭肝炎鸡胚化弱毒MY株进行纯粹检验；以100ELD50 0.2mL/枚(含病毒3.0×105个拷贝)剂量经鸡胚尿囊腔接种10日龄SPF鸡胚,每隔12h观察并采集鸡胚胚体和尿囊液样本,运用自行建立的检测DHV-1的SYBR Green I实时荧光定量RT-PCR方法检测MY株弱毒的鸡胚增殖规律.结果表明,该毒种符合...     

利用原生质体融合提高酿酒酵母赖氨酸含量的研究

以酿酒酵母（Saccharomyces cerevisiae)为出发菌株，经N-甲基-N‘-亚硝基胍（NTG）和紫外线（UV）诱变，选育出抗S-（2-氨基乙基）-L-半胱氨酸（AEC）和抗氯化理（LiCl)的抗药性菌株作为融合新株的细胞质基因标记。用100mg/ml蜗牛酶制备亲株的原生质体，两亲株的原生质体在35%PEG（MW6000），0.01mol/L CaCl2条件下被诱导融合，融合频率为10^-6 - 10^-7。试验表明，这些融合菌株具有杂种性质。其中一株产胞外赖氨酸的能力比亲株明显增强。     

湖南省鸽新城疫病毒的分离与鉴定

用SPF鸡胚从疑似鸽ND病鸽群中分离到一株病毒,根据HA、HI及病毒中和试验结果表明该分离毒为鸽NDV。其生物学特性ICPI为1.38,IVPI为1．0,MDT为99．8h,表现出与鸡NDV不同的生物学特性。     

鸡传染性法氏囊病地方流行毒株的分离与制苗种毒的筛选

从河北省昌黎县不同鸡场发生的法氏囊病鸡群中,分离到ＪＤ１,ＪＤ２,ＪＤ３,ＪＤ４,ＪＤ５共５株ＩＢＤ病毒毒株,通过初步分离与试验,并对其作了致病性、鸡胚适应性和免疫保护性等项试验。结果表明：所分离的５株均为ＩＢＤＶ,且可使易感鸡１００％发病,致死率在０～４０％。其中ＪＤ２和ＪＤ５可以在鸡胚中稳定增殖并使鸡胚规律性死亡。尽管通过鸡胚驯化,使分离的ＩＢ－ＤＶ毒力有所下降,但其灭活后免疫鸡,仍可使鸡对ＩＢＤ流行毒株的攻击达到８５％的保护率。ＪＤ２可作为ＩＢＤ囊组织抗原的种毒,也可作为ＩＢＤ鸡胚抗原的种毒。     

禽流感(AI)H9和新城疫二联灭活油佐剂疫苗的研制

从本地分离的禽流感（AI）-H9毒株和ND—lasota株，分别在9—11日龄的鸡胚增殖，灭活后用高压匀浆机乳化制成禽流感-H9,新城疫二联灭活油佐（乳）荆疫苗，经效力检验和攻毒试验结果表明，5日龄白羽肉鸡免疫后15天．抗体效价可达1：32以上，并能够保护免疫鸡免受AI的自然感染，ND的抗体效价也达到较高的水平。     

孔雀低致病性禽流感病毒株的分离与鉴定

用鸡胚分离方法从发病孔雀脑组织中分离病毒;将分离病毒进行血凝试验、血凝抑制试验、致病指数试验和半数致死量试验。结果表明,该株病毒可凝集鸡红血球,血凝性可被已知的禽流感(H9N2)抗体所抑制,脑内致病指数在1.6~2.5范围内,半数致死量,致病指数为50%,表明该病毒为低致病力禽流感毒株。     

21日龄鸡胚中金黄色葡萄球菌的PCR检测

为检测某鸡场21日龄鸡胚金黄色葡萄球菌感染情况, 针对其特有的耐热核酸酶基因(Nuc)设计并合成1对引物进行PCR扩增, 建立特异性检测金黄色葡萄球菌的PCR方法. 对18个21日龄鸡胚培养、分离, 获得18株疑似金黄色葡萄球菌菌落. 用建立的PCR方法对18份疑似样品进行扩增获得4份金黄色葡萄球菌的阳性扩增, 证实该鸡群21日龄鸡胚中金黄色葡萄球菌的感染率为22%(4/18). 本文中基于Nuc基因建立的PCR检测方法是检测鸡胚中金黄色葡萄球菌快速、特异的分子生物学方法.     

普通棉耳狨猴中乙型流感病毒的分离和鉴定

乙型流感病毒是引起人类局部流行性感冒的重要病原体，其起源和自然储存宿主目前仍不清楚。1999年夏季在某动物中心饲养的普通棉耳绒猴（Callithrix jacchus）群体中爆发了以呼吸道症状为主的急性传染病，死亡比率高达1／3。通过对死亡狨猴肺组织匀浆接种鸡胚和MDCK细胞的分离培养，分离出病毒。双份血清的红细胞凝集抑制试验证实，此分离株为此次狨猴群体感染流行的病原体。通过甲型和乙型流感病毒标准血清鉴定，证实该分离株为乙型流感病毒，命名为B/marmoset/China/1/99。     

鸡副粘病毒病的病毒特性和基因型研究及疫病防制

用ＳＰＦ鸡胚分别从不同患病鸡群中分离到４株病毒,经病毒学鉴定,该病毒为禽副粘病毒Ｉ型。根据在疫毒力的国际判定标准测定,４株病毒均属于新城商年;人工感染７１周龄ＳＰＦ鸡均１００％发病致死;应用１株鹅副粘病毒制备的具有对禽副粘病毒Ｉ型共同的群特异性单抗各仅对鹅副粘病毒毒株、鸡副粘病毒毒株呈阳性反应,而对新城疫Ｆ４８Ｅ８,Ｌａｓｏｔａ等毒株不发生反应的特异性单克隆抗体;应用ＲＴ－ＰＣＲ技术对禽副粘病毒Ｉ     

鸡传染性法氏囊病毒LS株的分离与鉴定

用SPF鸡胚,从江苏溧水某鸡场病死鸡的法氏囊组织中分离到一株病毒,接种健康非免疫鸡,能致鸡3～5 d内全部发病,死亡率达55%以上,腿肌和腺胃出血,肝和肾肿大出血,脾脏出血,法氏囊肿大出血;该病毒不能凝集鸡红细胞,可以与IBDV阳性血清产生沉淀;应用RT-PCR进行检测,扩增IBDV VP2基因,并与GenBank中的已知序列进行比较.结果表明,所分离的病毒为IBDV毒株.     

新城疫病毒TL1株的分离鉴定及部分生物学特性研究

新城疫是引起很多禽类发病并致死的一种烈性传染病．本研究通过对内蒙古分离株TL1株应用SPF鸡胚传代、电镜形态学观察、HA及HI试验、毒力鉴定、血凝解脱及血凝素热稳定性试验、动物感染试验等进行了研究。发现TL1株属于新城疫病毒强毒株,血凝素热稳定性较差,属快速血凝解脱型．     

鸡肾型传染性支气管炎的初步诊断与病毒分离

对河北省秦皇岛地区所发生的３起不同品种及不同日龄鸡肾型传染性支气管炎病例，进行了发病情况、临诊症状、病理变化及病原分离等方面的检验。以８只剖检病死鸡的肾脏作为病毒检验用材料，采用鸡胚尿囊腔途径接种并传代的方法，均分离到了病毒。所分得的病毒株均对鸡红细胞无血凝作用，与ＩＢ标准阳性抗血清做琼扩试验呈特异阳性反应，用１８日龄健康雏鸡做回归试验，复制出了同自然病例一样的肾型传染性支气管炎病例。同时，以８只剖检病死鸡的肝脏、肺脏、脾脏、肾脏等作为细菌检验用材料做抹片染色镜检及细菌分离，均未发现亦未分离出细菌     

Germline transmission of genetically modified primordial germ cells

Primordial germ cells (PGCs) are the precursors of sperm and eggs. In most animals, segregation of the germ line from the somatic lineages is one of the earliest events in development; in avian embryos, PGCs are first identified in an extra-embryonic region, the germinal crescent, after approximately 18 h of incubation. After 50-55 h of development, PGCs migrate to the gonad and subsequently produce functional sperm and oocytes. So far, cultures of PGCs that remain restricted to the germ line have not been reported in any species. Here we show that chicken PGCs can be isolated, cultured and genetically modified while maintaining their commitment to the germ line. Furthermore, we show that chicken PGCs can be induced in vitro to differentiate into embryonic germ cells that contribute to somatic tissues. Retention of the commitment of PGCs to the germ line after extended periods in culture and after genetic modification combined with their capacity to acquire somatic competence in vitro provides a new model for developmental biology. The utility of the model is enhanced by the accessibility of the avian embryo, which facilitates access to the earliest stages of development and supplies a facile route for the reintroduction of PGCs into the embryonic vasculature. In addition, these attributes create new opportunities to manipulate the genome of chickens for agricultural and pharmaceutical applications.     

Retroviral antigens on gs- chf- leukocytes

It has recently been suggested that the endogenous retroviruses present in many different species might be involved during stimulation of the immune system of their hosts. We have now studied the expression of two avian retroviral antigens p27 and gp85 in chicken lymphoid cells by indirect immunofluorescence (IIF) and by complement-dependent microcytotoxicity (CDM). We have now found that these viral antigens are expressed in peripheral blood leukocytes of adults and embryos and in splenic and bursal lymphocytes of Spafas gs- chf- chickens but they are not expressed in fibroblasts cultured from the feather follicles of the same individual adult birds nor in fibroblasts cultured from embryos of the same flock. The differential expression of viral antigens in leukocytes may be related to a specific property or function of these cells.     

Inability of Rous sarcoma virus to cause sarcomas in the avian embryo

The injection of Rous sarcoma virus (RSV) into the wing web of newly hatched chicks causes a rapidly growing sarcomatous tumour which is palpable within 1 week of inoculation; and cultures of fibroblasts derived from chick embryos (CEF) and infected with RSV become rapidly transformed. Genetic studies have determined that expression of a single viral gene, designated v-src, is necessary for neoplastic transformation. This gene codes for a 60,000-molecular weight phosphoprotein termed pp60SPC , which possesses a protein kinase activity that phosphorylates polypeptides on tyrosine residues and is constitutively expressed in infected CEF cells. It has been suggested that transformation, and possibly tumorigenesis, may result solely from the consequences of this increase in tyrosine phosphorylations. The pathogenicity of RSV in chick embryos in ovo is less clear. Murphy and Rous suggested that RSV may have caused tumours in "various tissues" of "some embryos", but the subsequent studies of Milford and Duran - Reynals , as well as several other laboratories, failed to find any evidence of intraembryonic tumours in RSV-infected early embryos. The findings of Duran - Reynals , if correct, cannot be explained easily in view of our present understanding of RSV tumorigenicity. Thus, we have re-examined the interaction of RSV with the avian embryo and confirm here that RSV is nontumorigenic and non-teratogenic when microinjected into day 4 chicken embryos. In addition, we found that (1) the virus not only replicates in the embryo, but it also expresses an active src-specific protein kinase and (2) once the cells from the infected limbs are disrupted and placed in culture, they are capable of expressing the transformed phenotype after a 24-h delay.     

鸟类分子生物学研究相关的Internet资源与常用软件

通过对互联网上的鸟类分子生物学资源进行数据挖掘、统计与分析,结果显示,当前鸟类的分子生物学研究资源已经相当丰富,尤其是在家鸡的全基因组测序之后,鸟类的分子生物学研究数据迅速上升,这一趋势仍将愈演愈烈.文中罗列了目前常用的互联网鸟类资源,以及相关软件的应用情况,对鸟类的基因组数据及基因组计划情况进行介绍与总结,相关信息通过表格形式详细列出.     

Histone genes are clustered with a 15-kilobase repeat in the chicken genome.

Histone mRNA isolated from 5-day-old chick embryos has been used as a template for complementary DNA (cDNA) synthesis. The resultant cDNA, after removal of sequences complementary to rRNA, was used to detect histone genes in adult chicken genomal DNA. Hybridisation data indicate that the histone genes are repeated about 10-fold in the chicken genome. Restriction endonuclease analysis reveals some sequence heterogeneity in these genes. However, the results show that chicken histone genes are clustered with a basic repeat unit of 15 kilobases.     

Generation of VP5 deficient mutant of infectious bursal disease virus strain HZ2

Infectious bursal disease virus (IBDV) is one of the most significant viral pathogens in chickens[1]. It causes high mortality in young chickens and establishes an immunosuppression state by destroying the precursorsInfectious bursal disease virus (IBDV) …     

H5N1亚型禽流感的诊断及临床病理学研究

对一起鸡传染病进行了病原鉴定并对其自然死亡的46例蛋鸡进行了临床病理学研究，结果表明，本起鸡病为A型禽流感，H5N1亚型，属高致死性(HPAI)；急性热性出血性败血症；急性坏死性胰腺炎；非化脓性脑炎；卡他性上呼吸道炎；卡他性、间质性肺炎。     

Three new types of viral oncogene of cellular origin specific for haematopoietic cell transformation.

The RNAs of seven replication-defective leukaemia virus (DLV) strains contain three types of unique sequences, which correlate with the capacity of a given virus strain to transform erythroblasts, macrophage-like cells and myeloblasts, respectively. These sequences, termed erb, mac and myb, have their counterparts in the normal DNA of avian and mammalian species. Our results indicate that DLVs represent recombinants between a common 'vector' related to a chicken endogenous virus and one of three types of cellular gene possibly involved in haematopoietic differentiation.