Abstract |
The Drosophila suppressor of position-effect variegation Su(var)3-9 encodes a heterochromatin-associated protein that is evolutionarily conserved. In contrast to its yeast and mammalian orthologs, the Drosophila Su(var)3-9 gene is fused with the locus encoding the gamma subunit of translation initiation factor eIF2. Synthesis of the two unrelated proteins is resolved by alternative splicing. A similar dicistronic Su(var)3-9/eIF-2gamma transcription unit was found in Clytus arietis, Leptinotarsa decemlineata, and Scoliopterix libatrix, representing two different orders of holometabolic insects (Coleoptera and Lepidoptera). In all these species the N terminus of the eIF-2gamma, which is encoded by the first two exons, is fused to SU(VAR)3-9. In contrast to Drosophila melanogaster, RT-PCR analysis in the two coleopteran and the lepidopteran species demonstrated the usage of a nonconserved splice donor site located within the 3' end of the SU(VAR)3-9 ORF, resulting in removal of the Su(var)3-9-specific stop codon from the mRNA and complete in-frame fusion of the SU(VAR)3-9 and eIF-2gamma ORFs. In the centipede Lithobius forficatus eIF-2gamma and Su(var)3-9 are unconnected. Conservation of the dicistronic Su(var)3-9/eIF-2gamma transcription unit in the studied insects indicates its origin before radiation of holometabolic insects and represents a useful tool for molecular phylogenetic analysis in arthropods.
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Authors | V Krauss, G Reuter |
Journal | Genetics
(Genetics)
Vol. 156
Issue 3
Pg. 1157-67
(Nov 2000)
ISSN: 0016-6731 [Print] United States |
PMID | 11063691
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- DNA Primers
- Drosophila Proteins
- Eukaryotic Initiation Factor-2
- Heterochromatin
- Protein Subunits
- Repressor Proteins
- Su(var)3-9 protein, Drosophila
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Topics |
- Amino Acid Sequence
- Animals
- Arthropods
(genetics)
- Base Sequence
- DNA Primers
- Drosophila
(genetics)
- Drosophila Proteins
- Drosophila melanogaster
(genetics)
- Eukaryotic Initiation Factor-2
(chemistry, genetics)
- Evolution, Molecular
- Exons
- Genes, Insect
- Heterochromatin
(genetics)
- Insecta
(genetics)
- Lepidoptera
(genetics)
- Molecular Sequence Data
- Phylogeny
- Protein Subunits
- Repressor Proteins
(chemistry, genetics)
- Reverse Transcriptase Polymerase Chain Reaction
- Sequence Alignment
- Sequence Homology, Amino Acid
- Species Specificity
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