title: [Ribosomal genes of the loach Misgurnus fossilis L. Isolation and restriction analysis].
abstract: The ribosomal DNA of the teleost fish--loach has been isolated from sperm DNA by CsCl density gradient centrifugation. The rDNA sediments on density gradients by two heavy satellites beta = 1.715 and greater than 1.720. The DNA of the first satellite (1.715) was separated and treated by restrictases EcoRI and BamHI. It was shown that there are two EcoRI-sites in rDNA of loach, locating in 18S and 28S rRNA coding sequences. From tandem of repeating ribosomal genes EcoRI cuts out the fragment with homogeneous length-3 megadaltons (constant fragment) and heterogeneous population of fragments 11-13 megadaltons (major) and 7-8 megadaltons (minor fraction). The constant fragment contains mostly 28S coding sequence, and the heterogeneous fragment--18S coding sequence. The data indicate that the ribosomal genes of the loach as well as other higher eucaryotes were organized in genome as tandem of repeating units with heterogeneous length (10-16 megadaltons, 14.5-24 kb) due to heterogeneity of the length of nontranscribed spacer.
mesh_terms: D000818:Animals; D001665:Binding Sites; D055598:Chemical Phenomena; D002621:Chemistry; D004247:DNA / Q000302:isolation & purification*; D004262:DNA Restriction Enzymes; D003720:Densitometry; D015245:Deoxyribonuclease BamHI; D015246:Deoxyribonuclease EcoRI; D005399:Fishes / Q000235:genetics*; D005796:Genes; D008297:Male; D012270:Ribosomes / Q000032:analysis; D013094:Spermatozoa / Q000648:ultrastructure*
chemical_list: D004247:DNA; D004262:DNA Restriction Enzymes; D015245:Deoxyribonuclease BamHI; D015246:Deoxyribonuclease EcoRI
vernacular_title: Ribosomnye geny v'iuna Misgurnus fossilis L. Vydelenie i restriktsionnyĭ analiz.