UNIFORM-DISTRIBUTION OF SATELLITE DNA VARIANTS ON THE CHROMOSOMES OF TENEBRIONID SPECIES ALPHITOBIUS-DIAPERINUS AND TENEBRIO-MOLITOR

The chromosomes of tenebrionid species Alphitobius diaperinus contain large blocks of pericentromerically located constitutive heterochromat in, as revealed by C-banding procedure. As previously reported, satell ite DNA of this species is composed of two related monomeric units org anized in three satellite subfamilies. In order to analyze the chromos omal location of the satellite DNA and the distribution of monomeric v ariants within it, and compare it with the distribution of monomer var iants in Tenebrio molitor satellite DNA, the methods of in situ hybrid ization and restriction enzyme/nick translation were performed. Fluore scent in situ hybridization with the entire satellite DNA reveals the pericentromerically located signals on all chromosomes of the compleme nt, coinciding with heterochromatic blocks. Results of fluorescent in situ hybridization with particular monomeric variants and of in situ r estriction enzyme/nick translation show that monomeric variants are ho mogeneously dispersed within the entire satellite DNA. The spreading o f satellite monomeric variants of the related species T. molitor withi n the pericentromeric heterochromatin of the entire complement, is dem onstrated using the method of in situ restriction enzyme/nick translat ion. Although the complexity of organization of satellite DNAs is quit e distinct in these two species, obtained results suggest similar effi ciency of mechanisms of spreading and homogenization resulting in rand om chromosomal distribution of their satellite variants.