title: Localization of ribosomal genes in Pleuronectiformes using Ag-, CMA3-banding and in situ hybridization.
abstract: In this paper we present the analysis of nucleolar organizer regions (NORs) in five species of the order Pleuronectiformes (Scophthalmus maximus, Scophthalmus rhombus, Platichthys flesus, Solea solea and Solea lascaris), a group of fish poorly studied cytogenetically. In spite of the small chromosome sizes, which characterize the karyotypes of this group, we implement both classical (Ag- and CMA3-staining) and molecular (in situ hybridization with a major rDNA probe) techniques for NOR location. NORs were localized in a single chromosome pair in all species studied and showed size variation within each species. Evidence of a NOR-site polymorphism was detected in Platichthys flesus and Scophthalmus maximus. NOR location was apparently the same within families (S. rhombus vs. S maximus, and S. solea vs. S. lascaris) but clearly differed among families, and supports the phylogenetic relationships proposed for the order Pleuronectiformes.
authors.affiliation: Departamento de Biología Fundamental, Area de Genética, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27002 Lugo, Spain.
authors.forename: B G
authors.initials: BG
authors.lastname: Pardo
authors.forename: C
authors.initials: C
authors.lastname: Bouza
authors.forename: J
authors.initials: J
authors.lastname: Castro
authors.forename: P
authors.initials: P
authors.lastname: Martínez
authors.forename: L
authors.initials: L
authors.lastname: Sánchez
mesh_terms: D000818:Animals; D002871:Chromosome Banding; D002875:Chromosomes / Q000235:genetics*; D004396:Coloring Agents / Q000378:metabolism; D004275:DNA, Ribosomal / Q000235:genetics*; D005412:Flatfishes / Q000235:genetics*; D020459:Genes, rRNA / Q000235:genetics; D017403:In Situ Hybridization; D007621:Karyotyping; D008677:Metaphase; D020161:Physical Chromosome Mapping; D016622:Silver Staining
chemical_list: D004396:Coloring Agents; D004275:DNA, Ribosomal