Satellite DNA repeat sequence variation is low in three species of burying beetles in the genus Nicrophorus (Coleoptera: Silphidae)

Three satellite DNA families were identified in three species of buryingbeetles, Nicrophorus orbicollis, N. marginatus, and N. americanus. Southernhybridization and nucleotide sequence analysis of individual randomlycloned repeats shows that these satellite DNA families are highly abundantin the genome, are composed of unique repeats, and are species-specific.The repeats do not have identifiable core elements or substructures thatare similar in all three families, and most interspecific sequencesimilarity is confined to homopolymeric runs of A and T. Satellite DNA fromN. marginatus and N. americanus show single-base-pair indels among repeats,but single-nucleotide substitutions characterize most of the repeatvariability. Although the repeat units are of similar lengths (342, 350,and 354 bp) and A + T composition (65%, 71%, and 71%, respectively), theaverage nucleotide divergence among sequenced repeats is very low (0.18%,1.22%, and 0.71%, respectively). Transition/transversion ratios from theconsensus sequence are 0.20, 0.69, and 0.70, respectively.