Analysis of Marek's disease virus (MDV) genes responsible for oncogenes is by MDV and protection of chickens from Marek's disease.

(1)马立克病病毒1型（MDV1）基因组肿瘤相关区序列的测定及转录本cDNA克隆的分离：(a)从感染MDV1的鸡胚成纤维细胞构建的cDNA文库中分离出MDV1基因组长倒重复区肿瘤相关区132bp串联直接重复序列的12个克隆。通过序列分析，在一个编码132bp重复序列mRNA的cDNA克隆中发现两个开放阅读框（ORF）。(b)对MDV1的9.3kb DNA进行核苷酸序列分析，包括肿瘤相关的132bp重复序列，发现存在14个潜在的orf。鉴定这些orf编码的蛋白质正在研究中。与疫苗免疫相关的MDV1基因分析：(a)确定了覆盖MDV1- ga株约70%短独特区（Us）和部分短倒置重复序列的DNA序列（8.9kb）。在8.9kb序列中的9个潜在orf中，发现4个与1型单纯疱疹病毒的US10、US3、US2和US6 （gD）同源。(b)利用杆状病毒载体显示US3编码MDV1特异性蛋白激酶(3)。表达大肠杆菌lacZ基因的重组MDV1的构建：我们尝试通过同源重组将大肠杆菌lacZ基因在22个位点插入MDV1基因组。其中，lacZ基因在4个位点的表达在培养连续传代过程中稳定表达。特别是，US10和US3基因对于诱导保护性免疫和体外病毒生长不是必需的(4)。MDV2限制性内切酶图谱的构建：构建了MDV2 DNA的BamHI、EcoRI和XhoI限制性内切酶图谱。我们发现三种血清型病毒基因组之间存在共线性关系(5)。用PCR方法区分MDV1的致癌株和非致癌株：从包含132bp重复序列的引物中选择引物，用PCR方法可以区分MDV1的致癌株和非致癌株。少

(1).Sequence determination of the tumor-associated region of the Marek's disease virus type 1 (MDV1) genome and isolation of cDNA clones of transcripts from the region : (a)Twelve clones carrying the 132bp tandem direct repeat, tumor associated region, within the long inverted repeat region of MDV1 genome were isolated from a cDNA library constructed from chick embryo fibro-blasts infected with MDV1. Two open reading frames (ORF) were found in a cDNA clone encoding the mRNA from the 132bp repeat by sequence analysis. (b)Nucleotide sequence analysis of 9.3kb DNA of MDV1, including the tumor-associated 132bp repeat revealed the presence of 14 potential ORFs. Identification of the proteins encoded from these ORFs is under investigation.(2).Analysis of MDV1 genes related to vaccinal immunity: (a)The DNA sequence (8.9kb) covering about 70% of the short unique region (Us) and part of the short inverted repeat of MDV1-GA strain was determined.Out of nine potential ORFs within the 8.9kb sequen … More ce, four were found to be homologous to US10, US3, US2, and US6 (gD) of herpes simplex virus type 1. (b)The US3 was shown to encode MDV1 specific protein kinase by using a baculovirus vector(3).Construction of recombinant MDV1 expressing the lacZ gene of Escherichia coli: We attempted to insert the Escherichia coli lacZ gene at 22 sites into the MDV1 genome by homologous recombination. Among them, expression of the lacZ gene at four sites were found to be stable during serial passages in culture. Especially, the US10 and US3 genes were nonessential for induction of protective immunity as well as for in vitro viral growth.(4).Construction of the restriction endonuclease map of MDV2: A BamHI, EcoRI, and XhoI restriction endonuclease map of MDV2 DNA was constructed. We showed the presence of the collinear relationship among viral genomes of three serotypes.(5).Differentiation of oncogenic and nononcogenic strains of MDV1 by using PCR: Differentiation of oncogenic and nononcogenic strains of MDV1 was possible by PCR using the primers chosen from the sequence including the 132bp repeat. Less