WOODCHUCK VIRUS--MOLECULAR BIOLOGICAL STUDIES

土拨鼠肝炎病毒（WHV）是分类和血清学 与B型肝炎病毒（HBV）有关。 感染这些病毒 病毒与急性和慢性肝炎及肝细胞 癌在各自的宿主，这些协会似乎是 本质上是病因学的。 因此，土拨鼠的WHV感染提供了一种 相关和方便的模型，了解人类HBV感染。 今年，我们进行了五个主要的研究领域。 首先，我们继续 我们对WHV X基因的研究发现， 对改变敏感，并且对于动物中的病毒复制是必需的 转染实验。 第二，X转录本的精细定位 启动子用于鉴定该顺式- 作用元素 第三，我们扩展了我们以前的实验， WHV双向启动子的表征。 第四，进步 是在试图确定蒙古旱獭肝炎病毒。 第五，两个WHV分离株显示发展为表面抗原血症， 肝脏肿瘤的发生率有显著差异。 后一项发现 对理解分子机制的重要意义 参与病毒复制和致癌潜力 嗜肝DNA病毒 因此，现在可以设计实验， 了解嗜肝DNA病毒致癌的机制。

The woodchuck hepatitis virus (WHV) is taxonomically and serologically related to the hepatitis B virus (HBV). Infection with each of these viruses is associated with acute and chronic hepatitis and hepatic cell carcinoma in their respective hosts and these associations appear to be etiological in nature. Thus, WHV infection of woodchucks provides a relevant and convenient model for understanding HBV infections of humans. Five major areas of study were pursued this year. First, we continued our investigations of the WHV X gene and found that this gene is very sensitive to alterations and is essential for viral replication in animal transfection experiments. Second, fine mapping of the X transcript promoter was used to identify the essential nucleotides in this cis- acting element. Third, we extended our previous experiments on the characterization of the bi-directional promoter of WHV. Fourth, progress was made in an attempt to identify a Mongolian marmot hepatitis virus. Fifth, two WHV isolates were shown to develop surface antigenemia and liver tumors at significantly different rates. The latter finding has important implications for understanding the molecular mechanisms involved in viral replication and in the oncogenic potential of hepadnaviruses. Thus, it is now possible to design experiments to understand the mechanism of hepadnavirus oncogenesis.