A comparative study of G+C-rich satellite components of sheep and goat DNA

Abstract

Restriction fragment patterns of G+C-rich satellites of sheep and goat DNA were compared. The 1,712 g/cm3 satellites of both species appear homologous, consisting of repeats 760 base pairs long and showing coincidence of position of primary+ EcoRI, BamHI and most BspRI restriction target sites. The EcoRI and BamHI endonucleases produce mostly monomers of the repeating unit, while oligomers prevail in the A1uI and Bg1II digests. Species-specific differences in the frequency, position and mode of distribution of secondary+ restriction target sites for EcoRI, Bg1II and A1uI were observed. Unlike the 1,712 g/cm3 satellites, the 1,723 g/cm3 component of sheep DNA and the 1,719 g/cm3 material from goat DNA appear species--specific, since no homologous material could ever be detected in the DNA of the other species.