title: Polytenization of the ribosomal genes on the X and Y chromosomes of Drosophila melanogaster.
abstract: It has previously been shown (Endow and Glover 1979), that polytenization of the ribosomal genes in D. melanogaster Ore-R X/Y cells and in hybrid X/X cells (Endow 1980) involves replication of genes predominantly from one of the cell's two nucleolus organizers. This analysis takes advantage of strain-specific differences in X and Y chromosome rDNA hybridization patterns detected using the Southern blotting technique. In this report, I extend the previous observations by examining polytene rDNA patterns in wild-type and hybrid X/Y cells. A dominance hierarchy for the X and Y chromosomes from three strains of D. melanogaster is presented and possible mechanisms of replicative dominance are discussed.
mesh_terms: D000818:Animals; D004261:DNA Replication; D004331:Drosophila melanogaster / Q000235:genetics*; D005260:Female; D005796:Genes; D008297:Male; D008540:Meiosis; D009693:Nucleic Acid Hybridization; D012335:RNA, Ribosomal / Q000235:genetics*; D014960:X Chromosome / Q000648:ultrastructure; D014998:Y Chromosome / Q000648:ultrastructure
chemical_list: D012335:RNA, Ribosomal