engleski

Evolution of Alpha‐Satellite DNA

Alpha satellite deoxyribonucleic acid (DNA) is based on 171-bp tandem repeats located in the centromeric and pericentromeric regions of all primate chromosomes. In humans, most of alpha satellite repeats are organized in a hierarchical fashion, creating complex units called higher order repeats (HORs), composed of 2 to over 30 diverged monomers in length. Monomeric alpha satellite DNA predates higher order arrays of alpha satellite and may represent direct descendant of the ancestral primate centromere sequence. Comparison of centromeric alpha satellite DNA sequences in different primate species reveals that alpha satellite DNA evolves through a series of amplification events resulting in the spreading of ‘new’ subfamilies which replace the ‘old’ ones and confer centromere function. Transcripts of alpha satellite play an important role in kinetochore formation and the establishment of pericentromeric heterochromatin, and are indispensable for the proper cell division.

alpha satellite DNA; higher order repeats; centromere; heterochromatin; concerted evolution

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