Intron loss from the NADH dehydrogenase subunit 4 gene of lettuce mitochondrial DNA: evidence for homologous recombination of a cDNA intermediate
| Autor: | K. T. Geiss, Christopher A. Makaroff, G. M. Abbas |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
DNA
Complementary Sequence analysis Molecular Sequence Data Restriction Mapping Lactuca Primary transcript DNA Mitochondrial Exon Species Specificity Vegetables Genetics Amino Acid Sequence Molecular Biology Gene Recombination Genetic Base Sequence Sequence Homology Amino Acid biology Intron NADH dehydrogenase food and beverages NADH Dehydrogenase Group II intron biology.organism_classification Molecular biology Introns biology.protein RNA Editing |
| Zdroj: | Molecular and General Genetics MGG. 243:97-105 |
| ISSN: | 1432-1874 0026-8925 |
| DOI: | 10.1007/bf00283881 |
| Popis: | The mitochondrial gene coding for subunit 4 of the NADH dehydrogenase complex I (nad4) has been isolated and characterized from lettuce, Lactuca sativa. Analysis of nad4 genes in a number of plants by Southern hybridization had previously suggested that the intron content varied between species. Characterization of the lettuce gene confirms this observation. Lettuce nad4 contains two exons and one group IIA intron, whereas previously sequenced nad4 genes from turnip and wheat contain three group IIA introns. Northern analysis identified a transcript of 1600 nucleotides, which represents the mature nad4 mRNA and a primary transcript of 3200 nucleotides. Sequence analysis of lettuce and turnip nad4 cDNAs was used to confirm the intron/exon border sequences and to examine RNA editing patterns. Editing is observed at the 5' and 3' ends of the lettuce transcript, but is absent from sequences that correspond to exons two, three and the 5' end of exon four in turnip and wheat. In contrast, turnip transcripts are highly edited in this region, suggesting that homologous recombination of an edited and spliced cDNA intermediate was involved in the loss of introns two and three from an ancestral lettuce nad4 gene. |
| Databáze: | OpenAIRE |
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