title: Isolation and characterization of two satellite DNAs in some Iberian rock lizards (Squamata, Lacertidae).
abstract: Satellite DNAs represent a large portion of all high eukaryotic genomes. They consist of numerous very similar repeated sequences, tandemly arranged in large clusters up to 100 million base pairs in length, usually located in the heterochromatic parts of chromosomes. The biological significance of satDNAs is still under discussion, but most of their proposed functions are related to heterochromatin and/or centromere formation and function. Because information about the structure of reptilian satDNA is far from exhaustive, we present a molecular and cytogenetic characterization of two satDNA families in four lacertid species. Two families of tandemly repeated DNAs, namely TaqI and HindIII satDNAs, have been cloned and sequenced from four species belonging to the genus Iberolacerta. These satDNAs are characterized by a monomer length of 171-188 and 170-172 bp, and by an AT content of 60.5% and 58.1%, respectively. FISH experiments with TaqI satDNA probe produced bright signals in pericentromeric regions of a subset of chromosomes whereas all the centromeres were marked by HindIII probe. The results obtained in this study suggest that chromosome location and abundance of satDNAs influence the evolution of these elements, with centromeric families evolving tenfold faster than interstitial/pericentromeric ones. Such different rates render different satellites useful for phylogenetic investigation at different taxonomic ranks.
authors.affiliation: Dipartimento di Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Giovannotti
authors.forename: Verónica
authors.initials: V
authors.lastname: Rojo
authors.forename: Paola
authors.initials: P
authors.lastname: Nisi Cerioni
authors.forename: Ana
authors.initials: A
authors.lastname: González-Tizón
authors.forename: Andrés
authors.initials: A
authors.lastname: Martínez-Lage
authors.forename: Andrea
authors.initials: A
authors.lastname: Splendiani
authors.forename: Horacio
authors.initials: H
authors.lastname: Naveira
authors.forename: Paolo
authors.initials: P
authors.lastname: Ruggeri
authors.forename: Óscar
authors.initials: Ó
authors.lastname: Arribas
authors.forename: Ettore
authors.initials: E
authors.lastname: Olmo
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Caputo Barucchi
mesh_terms: D000818:Animals; D001483:Base Sequence; D002875:Chromosomes / Q000235:genetics; D004276:DNA, Satellite / Q000235:genetics* / Q000302:isolation & purification; D019143:Evolution, Molecular; D016678:Genome; D006570:Heterochromatin / Q000235:genetics*; D017404:In Situ Hybridization, Fluorescence; D008116:Lizards / Q000235:genetics*; D010802:Phylogeny
chemical_list: D004276:DNA, Satellite; D006570:Heterochromatin