Satellite DNA of the red flour beetle Tribolium castaneum--comparative study of satellites from the genus Tribolium |
| |
Authors: | Ugarkovic D; Podnar M; Plohl M |
| |
Institution: | Department of Molecular Genetics, Ruder Boskovic Institute, Zagreb, Croatia. ugarkov@olimp.irb.hr |
| |
Abstract: | A highly abundant satellite DNA comprising 17% of the Tribolium castaneum
(Insecta, Coleoptera) genome was cloned and sequenced. The satellite
monomer is 360 bp long, has a high A+T content of 73%, and lacks
significant internal substructures. The sequence variability is 3.6%,
essentially due to random distribution of single-point mutations. The
satellite is evenly distributed in the regions of centromeric
heterochromatin of all 20 chromosomes, as shown by fluorescent in situ
hybridization. Comparison of T. castaneum satellite with those from three
different but congeneric species reveals the highest sequence similarity of
47.1% with the satellite from the sibling species Tribolium freemani. The
phylogenetic relationships among Tribolium species deduced from satellite
sequence agree with those based on karyological, chemotaxonomic, and
hybridization data. This indicates a parallel in the divergence of
satellites and some genetic and cytogenetic characters. Despite low mutual
sequence similarity, which makes them species-specific, Tribolium
satellites have a common structural characteristic: a block of about 95%
A+T content, 20 to 42 bp long, flanked at one side by an inverted repeat
which can potentially form a thermodynamically stable dyad structure. Since
similar structural features are found in centromeric DNA of Saccharomyces
cerevisiae and Chironomus pallidivittatus, their possible importance in
centromere function may be inferred.
|
| |
Keywords: | |
本文献已被 Oxford 等数据库收录! |
|