Leib-Mösch C, Seifarth W
III. Medizinische Klinik, Klinikum Mannheim, Universität Heidelberg, Mannheim, Federal Republic of Germany.
Virus Genes. 1995;11(2-3):133-45. doi: 10.1007/BF01728654.
Retroelements comprise a substantial portion of the human genome. Their large number and ubiquitous distribution has led scientists to speculate about their evolutionary origin and their biological functions. Human endogenous retroviruses and their retrotransposon relatives represent a reservoir of possibly pathogenic retroviral genes that may be activated spontaneously or by environmental conditions. They can act as insertion mutagens and activate or inactivate cellular genes, or may be involved in chromosome aberrations by recombination of related elements on different chromosomal locations. Retroviral gene products themselves may also be pathogenic and, for example, could be implicated in the development of tumors and autoimmune diseases. On the other hand, endogenous retroviral elements and nonviral retroposons are thought to have played an important role in shaping the genomes of vertebrates by intracellular transposition events and by generating hot spots of recombination. In the course of time, some of these elements have acquired cellular functions, such as, for instance, in the regulation of gene expression. Therefore, the role of human endogenous retroviruses and retroposons in biological processes is currently a subject of great interest.
逆转录元件构成了人类基因组的很大一部分。它们数量众多且分布广泛，这使得科学家们对其进化起源和生物学功能进行了推测。人类内源性逆转录病毒及其逆转座子亲属代表了一个可能致病的逆转录病毒基因库，这些基因可能会自发激活或因环境条件而激活。它们可以作为插入诱变剂，激活或使细胞基因失活，或者可能通过不同染色体位置上相关元件的重组参与染色体畸变。逆转录病毒基因产物本身也可能具有致病性，例如，可能与肿瘤和自身免疫性疾病的发生有关。另一方面，内源性逆转录病毒元件和非病毒逆转座子被认为通过细胞内转座事件和产生重组热点在塑造脊椎动物基因组方面发挥了重要作用。随着时间的推移，其中一些元件获得了细胞功能，例如在基因表达调控方面。因此，人类内源性逆转录病毒和逆转座子在生物过程中的作用目前是一个备受关注的课题。
