Heterochromatic Stellate gene cluster in Drosophila melanogaster: structure and molecular evolution.
The 30-kb cluster comprising close to 20 copies of tandemly repeated Stellate genes was localized in the distal heterochromatin of the X chromosome. Of 10 sequenced genes, nine contain undamaged open reading frames with extensive similarity to protein kinase CK2 beta-subunit; one gene is interrupted by an insertion. The heterochromatic array of Stellate repeats is divided into three regions by a 4.5-kb DNA segment of unknown origin and a retrotransposon insertion: the A region (approximately 14 Stellate genes), the adjacent B region (approximately three Stellate genes), and the C region (about four Stellate genes). The sequencing of Stellate copies located along the discontinuous cluster revealed a complex pattern of diversification. The lowest level of divergence was detected in nearby Stellate repeats. The marginal copies of the A region, truncated or interrupted by an insertion, escaped homogenization and demonstrated high levels of divergence. Comparison of copies in the B and C regions, which are separated by a retrotransposon insertion, revealed a high level of diversification. These observations suggest that homogenization takes place in the Stellate cluster, but that inserted sequences may impede this process.
Tulin
A V
AV
Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia.
Kogan
G L
GL
Filipp
D
D
Balakireva
M D
MD
Gvozdev
V A
VA
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004247:DNA; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics*; D019143:Evolution, Molecular; D008040:Genetic Linkage; D006570:Heterochromatin / Q000235:genetics*; D019476:Insect Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family; D011494:Protein Kinases; D012091:Repetitive Sequences, Nucleic Acid; D014960:X Chromosome
D029721:Drosophila Proteins; D006570:Heterochromatin; D019476:Insect Proteins; D004247:DNA; D011494:Protein Kinases; C094331:Ste protein, Drosophila