An alien promoter capture as a primary step of the evolution of testes-expressed repeats in the Drosophila melanogaster genome
| Autor: | Vladimir A. Gvozdev, Lev A. Usakin, G. L. Kogan, Alla Kalmykova |
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| Rok vydání: | 2005 |
| Předmět: |
Transposable element
Male Immunoblotting Molecular Sequence Data Chimeric gene Biology Genome Evolution Molecular Suppression Genetic RNA interference Genes Reporter Sequence Homology Nucleic Acid Y Chromosome Genetics Gene silencing Animals Drosophila Proteins Gene conversion Gene Silencing Promoter Regions Genetic Molecular Biology Gene Ecology Evolution Behavior and Systematics Repetitive Sequences Nucleic Acid Base Sequence fungi biology.organism_classification Drosophila melanogaster Tandem Repeat Sequences DNA Transposable Elements RNA Interference Protein Kinases |
| Zdroj: | Molecular biology and evolution. 22(7) |
| ISSN: | 0737-4038 |
| Popis: | Fertility of Drosophila melanogaster males is impaired due to the disruption of the silencing of the X-linked, testis-expressed, repeated Stellate (Ste) genes. Ste silencing is mediated by symmetric transcription of the paralogous Y-linked repeats and exerted by an RNA interference (RNAi) mechanism. Here we present a scenario for the origin of the Ste genes and their suppressors. The primary intermediate of their evolution emerged as a result of the acquisition of a preformed alien, testis-specific promoter. This intermediate is identified as a chimeric gene containing coding region of an autosomal gene for testis-specific protein kinase CK2. The 5' region of the chimera has been acquired from a member of a family of testis-expressed X-linked genes of unknown function. We propose that the evolution and amplification of the novel chimeric gene have led to the overproduction of the regulatory CK2 subunit in testes. The evolution of the Y-linked descendants of the primary intermediate resulted in the RNAi-mediated suppression of excessive expression of the X-linked paralogs. The newly detected "dead family" of cognate repeats on the Y chromosome has contributed to the evolution of Ste and its suppressors via gene conversion. Our results show that RNAi silencing, considered as a defense against viruses and transposable elements, may be involved in the evolution of eukaryotic genomes. |
| Databáze: | OpenAIRE |
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