Interspersed centromeric element with a CENP-B box-like motif in Chironomus pallidivittatus

Abstract

Short mobile elements are present in different recombined forms as interspersed GC-rich islands between AT rich centromeric 155 bp tandem repeats in the dipteran Chironomus pallidivittatus. The basic element is 80 bp long, has a pronounced invert repeat structure and contains a 17 bp segment similar to the CENP-B box in mammals. The element inserts into a specific site of the 155 bp repeat in a defined orientation surrounded by 2 bp direct repeats. The total number per genome of the main variant is < 20. Elements can be present in all centromeres from C. pallidivittatus and the sibling species Chironomus tentans with pronounced differences in distribution within and between species.