title: Reciprocal recombination and the evolution of the ribosomal gene family of Drosophila melanogaster.
abstract: The role of reciprocal recombination in the coevolution of the ribosomal RNA gene family on the X and Y chromosomes of Drosophila melanogaster was assessed by determining the frequency and nature of such exchange. In order to detect exchange events within the ribosomal RNA gene family, both flanking markers and restriction fragment length polymorphisms within the tandemly repeated gene family were used. The vast majority of crossovers between flanking markers were within the ribosomal RNA gene region, indicating that this region is a hotspot for heterochromatic recombination. The frequency of crossovers within the ribosomal RNA gene region was approximately 10(-4) in both X/X and X/Y individuals. In conjunction with published X chromosome-specific and Y chromosome-specific sequences and restriction patterns, the data indicate that reciprocal recombination alone cannot be responsible for the observed variation in natural populations.
authors.affiliation: Department of Zoology, University of Alberta, Edmonton.
authors.forename: S M
authors.initials: SM
authors.lastname: Williams
authors.forename: J A
authors.initials: JA
authors.lastname: Kennison
authors.forename: L G
authors.initials: LG
authors.lastname: Robbins
authors.forename: C
authors.initials: C
authors.lastname: Strobeck
mesh_terms: D000818:Animals; D005075:Biological Evolution; D003434:Crossing Over, Genetic; D004275:DNA, Ribosomal / Q000235:genetics*; D004331:Drosophila melanogaster / Q000235:genetics*; D005260:Female; D005819:Genetic Markers; D014644:Genetic Variation; D008297:Male; D005810:Multigene Family; D012150:Polymorphism, Restriction Fragment Length; D011995:Recombination, Genetic; D014960:X Chromosome; D014998:Y Chromosome
chemical_list: D004275:DNA, Ribosomal; D005819:Genetic Markers