STRUCTURE AND REPLICATION OF HEPATITIS DELTA VIRUS

本提案的目的是促进最终了解 逆转录酶如何参与生殖细胞系的生成 细胞，类基因元件和加工基因。 一组目标是追求观察，在内源性 蜂毒素破坏的鹌鹑生长逆转录病毒的RNA定向DNA合成 使用tRNA大小的引物逆转录细胞7S-L RNA， 产生一个主要的离散的130 b种类的DNA。 这种观察是双重的。 真诱人 首先，它提出了一个类比的早期事件， 逆转录的禽逆转录病毒基因组中，tRNA.trp是 用作引物，用于转录特定的101 b物种， RNA基因组的5 '-末端。 其次，它表明，观察到的相反 7S-L RNA的转录可能是细胞的DNA被转录的过程中的一个步骤。 真核细胞已经积累了多个拷贝， 类元素。 之所以提出这一建议，是因为这些要素 序列长度约为130 b，与 7S-L RNA的5 '-末端。 因此，拟议的研究将测试 7S-L RNA的假设，即细胞的逆转录， RNA可能不仅参与了病毒的产生和传播， 类基因元件，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，因为它们可能需要，尽管 很少，逆转录事件发生在生殖系细胞中。 为 因此，第二组目标是针对潜在的 逆转录酶。 通过高严格性杂交， 鹌鹑不含与禽白血病逆转录酶相关的DNA 病毒 然而，随着严格性的降低，已经可以检测到并且 在λ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， 它们在鹌鹑胚胎组织中以RNA形式表达。 的序列 还将测试与逆转录病毒样病毒的关系， 据报道，在研究中， 霍夫施耐德和同事的照片

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.