engleski

Sequence conservation among satellite DNAs of the genus Pimelia (Tenebrionidae, Coleoptera)

Highly and tandemly repeated DNAs have been characterized in six species from the genus Pimelia (Coleoptera, Insecta). Samples of the alopatric species P. interjecta, P. integra, P. variolosa, and P. baetica were collected from different locations of the Iberian peninsula, while insular species P. criba and P. elevata were from the Balearic islands, Mallorca and Ibiza, respectivelly. Analysed species showed the presence of a single satellite DNA with the basic monomer length of about 357 bp comprising a considerable ammount of the genome (39% - 45%). Satellites are equilocated in the regions of pericentromeric heterochromatin, are A+T rich and exhibit curvature, resulting in the left-handed superhelical structure. In spite of the high homology among these satellites they can be grouped in two clusters: comprising satellites from P. variolosa, P. baetica, and P. integra, and the other with satellites from P. criba, P. elevata and P. interjecta. Within the groups, satellite clones are not clustered species-specifically, except those of P. integra, where species-diagnostic nt substitutions are detected. Thus, we have found a high sequence conservation among the satellites from these six Pimelia species in contrast with the previously characterized satellites from the same family Tenebrionidae. These contrasting patterns could be due to a recent process of speciation within the genus Pimelia, or to different molecular mechanisms driving the evolution of the satellite sequences in diverse genera.

DNA evolution; highly repetitive DNA; DNA curvature; substitution rate; satelite DNA

nije evidentirano