title: Molecular characterization and evolution of an interspersed repetitive DNA family of oysters.
abstract: When genomic DNA from the European flat oyster Ostrea edulis L. was digested by BclI enzyme, a band of about 150 bp was observed in agarose gel. After cloning and sequencing this band and analysing their molecular characteristics and genomic organization by means of Southern blot, in situ hybridisation, and polymerase chain reaction (PCR) protocols, we concluded that this band is an interspersed highly repeated DNA element, which is related in sequence to the flanking regions of (CT)-microsatellite loci of the species O. edulis and Crassostrea gigas. Furthermore, we determined that this element forms part of a longer repetitive unit of 268 bp in length that, at least in some loci, is present in more than one copy. By Southern blot hybridisation and PCR amplifications-using primers designed for conserved regions of the 150-bp BclI clones of O. edulis-we determined that this repetitive DNA family is conserved in five other oyster species (O. stentina, C. angulata, C. gigas, C. ariakensis, and C. sikamea) while it is apparently absent in C. gasar. Finally, based on the analysis of the repetitive units in these oyster species, we discuss the slow degree of concerted evolution in this interspersed repetitive DNA family and its use for phylogenetic analysis.
authors.affiliation: Departamento de Genética, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
authors.forename: Inmaculada
authors.initials: I
authors.lastname: López-Flores
authors.forename: Carmelo
authors.initials: C
authors.lastname: Ruiz-Rejón
authors.forename: Ismael
authors.initials: I
authors.lastname: Cross
authors.forename: Laureana
authors.initials: L
authors.lastname: Rebordinos
authors.forename: Francisca
authors.initials: F
authors.lastname: Robles
authors.forename: Rafael
authors.initials: R
authors.lastname: Navajas-Pérez
authors.forename: Roberto
authors.initials: R
authors.lastname: de la Herrán
mesh_terms: D000818:Animals; D001483:Base Sequence; D049896:Crassostrea / Q000235:genetics*; D020732:Cytogenetic Analysis; D004247:DNA / Q000235:genetics*; D017931:DNA Primers; D004251:DNA Transposable Elements; D019143:Evolution, Molecular; D056426:Genetic Loci; D017404:In Situ Hybridization, Fluorescence; D018895:Microsatellite Repeats; D008969:Molecular Sequence Data; D049895:Ostrea / Q000235:genetics*; D010802:Phylogeny
chemical_list: D017931:DNA Primers; D004251:DNA Transposable Elements; D004247:DNA