title: Comparative cytogenetics in four species of Palinuridae: B chromosomes, ribosomal genes and telomeric sequences.
abstract: The evolutionary pathway of Palinuridae (Crustacea, Decapoda) is still controversial, uncertain and unexplored, expecially from a karyological point of view. Here we describe the South African spiny lobster Jasus lalandii karyotype: n and 2n values, heterochromatin distribution, nucleolar organizer region (NOR) location and telomeric repeat structure and location. To compare the genomic and chromosomal organization in Palinuridae we located NORs in Panulirus regius, Palinurus gilchristi and Palinurus mauritanicus: all species showed multiple NORs. In J. lalandii NORs were located on three chromosome pairs, with interindividual polymorphism. In P. regius and in the two Palinurus species NORs were located on two chromosome pairs. In the two last species 45S ribosomal gene loci were also found on B chromosomes. In addition, the nature and location of telomeric repeats were investigated by FISH in J. lalandii, P. gilchristi, P. mauritanicus Palinurus elephas, and P. regius (Palinuridae, Achelata), and in Scyllarus arctus (Scyllaridae, Achelata): all these Achelata species showed the (TTAGG)n pentameric repeats. Furthermore, in J. lalandii these repeats occurred in all the telomeres and in some interstitial chromosomal sites, associated with NORs.
authors.affiliation: Dipartimento di Scienze della Vita e dell'Ambiente, Università di Cagliari, Via T. Fiorelli 1, 09126, Cagliari, Italy. salvador@unica.it
authors.forename: Susanna
authors.initials: S
authors.lastname: Salvadori
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Coluccia
authors.forename: Federica
authors.initials: F
authors.lastname: Deidda
authors.forename: Angelo
authors.initials: A
authors.lastname: Cau
authors.forename: Rita
authors.initials: R
authors.lastname: Cannas
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Deiana
mesh_terms: D000818:Animals; D002871:Chromosome Banding / Q000379:methods; D020459:Genes, rRNA; D056426:Genetic Loci; D006570:Heterochromatin / Q000235:genetics*; D017404:In Situ Hybridization, Fluorescence; D059785:Karyotype; D009697:Nucleolus Organizer Region / Q000235:genetics; D033521:Palinuridae / Q000235:genetics*; D016615:Telomere / Q000235:genetics*
chemical_list: D006570:Heterochromatin