STRUCTURE AND REPLICATION OF HEPATITIS DELTA VIRUS

这项建议的目标是有助于最终理解 逆转录酶如何参与胚系中的世代 由类铝元素和加工基因组成的细胞。 一组目标是追求观察到在内生的 以RNA为导向的蜂毒素破坏的鹌鹑生长逆转录病毒的DNA合成 细胞7S-L使用tRNA大小的引物进行逆转录 产生一种主要的离散的130b种DNA。这一观察结果是双重的 很诱人。首先，它提出了一个与早期事件的类比 禽类逆转录病毒基因组中tRNA.trp是 作为一种特定的101b物种转录的引物 RNA基因组的5‘端。其次，它表明观察到的反转 7S-L核糖核酸的转录可能是该过程中的一个步骤 真核细胞积累了多个拷贝的被称为 类铝元素。之所以提出这一建议，是因为这些要素 大约130b长，并显示出与 7S-L核糖核酸的5‘末端。因此，拟议的研究将考验 7S-L核糖核酸--他人关于细胞反转录的假说 RNA可能不仅参与了病毒的产生和传播 类铝元素，但也有某些假基因、加工基因和基因 转换事件。这些现象都类似于 内源性逆转录病毒样DNA元件可能需要，尽管 在生殖系细胞中很少发生逆转录事件。为 因此，第二组目标针对的是潜在的 鹌鹑体内的逆转录酶。通过高度严格的杂交， 鹌鹑体内没有与禽白血病逆转录酶相关DNA 病毒。然而，随着严格程度的降低，已经可以检测到 在lambda载体中克隆与逆转录病毒相关的序列 聚合酶基因。这些序列的结构将被确定并 以RNA的形式检测其在鹌鹑胚胎组织中的表达。这些序列 也将测试与逆转录病毒样病毒的关系 据报道，在这项研究中，从胚胎组织中释放的颗粒 霍夫施奈德和他的同事。

The goal of this proposal is to contribute to the eventual understanding of how reverse transcriptase participates in the generation, in germ line cells, of Alu-like elements and processed genes. One group of aims is to pursue the observation that in the endogenous RNA-directd DNA snythesis of melittin-disrupted quail-grown retrovirus, the cellular 7S-L RNA is reverse transcribed using a tRNA-sized primer to generate a major discrete 130b species of DNA. This observation is doubly tantalizing. Firstly, it suggests an analogy to the early events in the reverse transcription of the avian retroviral genome in whch tRNA.trp is used as primer for the transcription of a specific 101b species from the 5'-end of the RNA genome. Secondly, it suggests that the observed reverse transcription of 7S-L RNA may be a step in the process by which the DNA of eucaryotic cells has accumulated multiple copies of what are referred to as Alu-like elements. This suggestion is made because such elements are fequently about 130b long and show significant sequence-relatedness to the 5'-terminus of the 7S-L RNA. The studies proposed will therefore test for 7S-L RNA the hypothesis of others that reverse transcription of cellular RNA's may be involved not only in the generation and transmission of Alu-like elements but also of certain pseudogenes, processed genes and gene conversion events. Such phenomena are all analogous to the formation of endogenous retrovirus-like DNA elements in that they could require, albeit rarely, reverse transcription events to take place in germ line cells. For this reason the second group of aims are directed at potential sources of reverse transcriptase in the quail. By high stringency hybridization the quail is free of DNA related to the reverse transcriptase of avian leukosis virus. However, with lowered stringency it has been possible to detect and clone in a lambda vector sequences that are related to the retroviral polymerase gene. The structure of these sequences will be determined and their expression as RNA assayed in quail embryonic tissues. The sequences will also be tested for relationship to those of the retrovirus-like particles, reportedly released from embryonic quail tissues, in the studies of Hofschneider and coworkers.