Naslov
A GC-rich satellite DNA and karyology of the bivalve mollusc Donax trunculus: a dominance of GC-rich heterochromatin

Autori
Petrović, Vlatka ; Perez-Garcia, Concepcion ; Pasantes, Juan ; Šatović, Eva ; Prats, Eva ; Plohl, Miroslav

Izvornik
Cytogenetic and genome research (1424-8581) 124 (2009), 1; 63-71

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
tandem repeats ; subtelomeric heterochromatin ; fluorochrome banding ; FISH

Sažetak
We characterized the DTF2 satellite DNA family of the clam Donax trunculus and compared its chromosomal localization with cytogenetic data revealed by fluorochrome banding, C-banding and 28 S rDNA FISH. In contrast to the other satellites detected previously in this species, DTF2 is an abundant (2 %) GC rich satellite that exhibits CpG methylation. Sequence characteristics of DTF2 indicate that its evolution is not affected by constraints that might indicate some functional interactions. Fluorescence in situ hybridization revealed subtelomeric location of this satellite on a subset of 14 out of 19 D. trunculus chromosome pairs. The chromomycin A3 (CMA) staining of GC-rich regions on D. trunculus chromosomes revealed a complex banding pattern that overlaps completely with C-bands. In total, only three bands show subtelomeric location, while 13 bands are located interstitially, one of them being coincident with the 28S rDNA hybridization signal. No bands, either CMA positive (GC-rich) or DAPI positive (AT-rich) were detected at centromeric chromosomal positions. Only two of the CMA-positive bands co-localize with DTF2 satellite, showing (i) the presence of small islands of GC-rich repetitive sequences that remained undetected by CMA/C-banding, and (ii) the abundance of DTF2-divergent GC-rich sequences at interstitial chromosomal locations.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

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