Retrotransposable elements R1 and R2 interrupt the rRNA genes of most insects.
نویسندگان
چکیده
منابع مشابه
R1 and R2 retrotransposable elements of Drosophila evolve at rates similar to those of nuclear genes.
The non-long-terminal repeat retrotransposable elements, R1 and R2, insert at unique locations in the 28S ribosomal RNA genes of insects. Based on the nucleotide sequences of these elements in the eight members of the melanogaster species subgroup of the genus Drosophila, they have been maintained by vertical germline transmission for the 17-20 million year history of this subgroup. The stable ...
متن کاملRetrotransposable elements R1 and R2 in the rDNA units of Drosophila mercatorum: abnormal abdomen revisited.
R1 and R2 retrotransposable elements are stable components of the 28S rRNA genes of arthropods. While each retrotransposition event leads to incremental losses of rDNA unit expression, little is known about the selective consequences of these elements on the host genome. Previous reports suggested that in the abnormal abdomen (aa) phenotype of Drosophila mercatorum, high levels of rDNA insertio...
متن کاملSequence relationship of retrotransposable elements R1 and R2 within and between divergent insect species.
R1 and R2 are retrotransposable elements that integrate at specific sites in the 28S ribosomal RNA (rRNA) genes of Bombyx mori and Drosophila melanogaster. We have previously shown that most insect species contain insertions in their 28S genes at the R1 and/or R2 site. We have sequenced the 3' half of R1 and R2 elements from three additional insect species: the fungus gnat, Sciara coprophila (D...
متن کاملVertical transmission of the retrotransposable elements R1 and R2 during the evolution of the Drosophila melanogaster species subgroup.
R1 and R2 are non-long-terminal repeat retrotransposable elements that insert into specific sequences of insect 28S ribosomal RNA genes. These elements have been extensively described in Drosophila melanogaster. To determine whether these elements have been horizontally or vertically transmitted, we characterized R1 and R2 elements from the seven other members of the melanogaster species subgro...
متن کاملChromatin structure and transcription of the R1- and R2-inserted rRNA genes of Drosophila melanogaster.
About half of the rRNA gene units (rDNA units) of Drosophila melanogaster are inserted by the retrotransposable elements R1 and R2. Because transcripts to R1 and R2 were difficult to detect on blots and electron microscopic observations of rRNA synthesis suggested that only uninserted rDNA units were transcribed, it has long been postulated that inserted rDNA units are in a repressed (inactive)...
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ژورنال
عنوان ژورنال: Proceedings of the National Academy of Sciences
سال: 1991
ISSN: 0027-8424,1091-6490
DOI: 10.1073/pnas.88.8.3295