Retroposons do jump: a B2 element recently integrated in an 18S rDNA gene
| Autor: | Ilse Oberbäumer |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1992 |
| Předmět: |
Molecular Sequence Data
Restriction Mapping Biology DNA Ribosomal Polymerase Chain Reaction Cell Line Mice Genetics RNA Precursors RNA Ribosomal 18S Direct repeat Animals Ribosomal DNA Repetitive Sequences Nucleic Acid Base Sequence cDNA library Retroposon Ribosomal RNA Blotting Northern Molecular biology RRNA transcription External transcribed spacer genomic DNA DNA Transposable Elements Pseudogenes |
| Popis: | Several cDNA clones were isolated from cDNA libraries constructed with mRNA longer than 28S RNA from the murine cell line PYS-2/12. The plasmids have inserts containing 1-1.2 kb of the ribosomal 5' external transcribed spacer followed by nearly 700 nt of sequence for 18S rRNA and ending with a B2 element (retroposon). The cloned sequence differed in a few positions from published ribosomal sequences. The 3' adjacent genomic sequence was obtained by polymerase chain reaction (PCR) and showed that the B2 element has a poly(A) tail of about 50 nt and is surrounded by perfect direct repeats of 15 nt. Analysis of genomic DNA from several murine cell lines revealed that PYS cells contain at least one copy of 18S RNA with the B2 element which is not present in the genome of other murine cell lines derived from the same teratocarcinoma. Similarly, rRNA transcripts containing the B2 element were only detected in PYS cells. According to the publication dates of the different cell lines, the B2 element must have been integrated into an rRNA transcription unit during the years 1970 through 1974 thus proving that retroposons (SINEs) can still be inserted into the genome in our times. |
| Databáze: | OpenAIRE |
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