title: Chromosomal location polymorphism of major rDNA sites in two Mediterranean populations of the killifish Aphanius fasciatus (Pisces: Cyprinodontidae).
abstract: The chromosomes of the Mediterranean killifish, Aphanius fasciatus from two populations, the Lagoon of Venice (LV, 15 specimens) and the Lagoon "Stagnone di Marsala" (Sicily) (SM, 48 specimens), have been investigated using conventional Ag-staining and fluorescent in situ hybridization (FISH) with 18S rDNA probe. The two methods revealed variation in the number of major rDNA sites ranging from 8 to 14 (LV) and from 1 to 4 (SM) per individual. The fact that each individual possessed its own number of sites implies that observed variation was structural. Moreover, overlapping of silver staining and FISH patterns demonstrated that all ribosomal genes were transcriptionally active in each specimen.
authors.affiliation: Dipartimento di Biologia Animale, Università di Palermo, Via Archirafi 18, 90123 Palermo, Italy. zuvitcol@unipa.it
authors.forename: Roberto
authors.initials: R
authors.lastname: Vitturi
authors.forename: Mariastella
authors.initials: M
authors.lastname: Colomba
authors.forename: Salvatrice
authors.initials: S
authors.lastname: Vizzini
authors.forename: Angelo
authors.initials: A
authors.lastname: Libertini
authors.forename: Rainer
authors.initials: R
authors.lastname: Barbieri
authors.forename: Antonio
authors.initials: A
authors.lastname: Mazzola
mesh_terms: D000818:Animals; D002875:Chromosomes / Q000235:genetics / Q000648:ultrastructure; D004275:DNA, Ribosomal / Q000235:genetics*; D005260:Female; D023781:Fundulidae / Q000235:genetics*; D005828:Genetics, Population; D017404:In Situ Hybridization, Fluorescence; D007558:Italy; D007621:Karyotyping; D008297:Male; D009697:Nucleolus Organizer Region / Q000648:ultrastructure; D011110:Polymorphism, Genetic; D012834:Silver; D013194:Staining and Labeling
chemical_list: D004275:DNA, Ribosomal; D012834:Silver