6533b7d2fe1ef96bd125f7a2

RESEARCH PRODUCT

Cytogenetics of the land snails Cantareus aspersus and C. mazzullii (Mollusca: Gastropoda: Pulmonata).

Mariastella ColombaAntonella LanninoAngelo LibertiniArmando GregoriniIgnazio SparacioRoberto VitturiLuca Sineo

subject

medicine.medical_specialtySnailsGeneral Physics and AstronomyPulmonataDNA RibosomalGiemsa stainSilver stainchemistry.chemical_compoundCytogeneticsSpecies SpecificityStructural BiologyGastropodamedicineAnimalsGeneral Materials ScienceIn Situ Hybridization FluorescenceRepetitive Sequences Nucleic AcidbiologyBase SequenceStaining and LabelingCytogeneticsCell BiologyDNATelomerebiology.organism_classificationMolecular biologyStainingNuclear DNAChromosome BandingchemistryKaryotypingDNA

description

A cytogenetic study was carried out on the chromosomes and nuclear DNA contents of the land snails Cantareus aspersus and C. mazzullii (Gastropoda: Pulmonata). Chromosomes were studied using Giemsa staining, banding methods and fluorescent in situ hybridization (FISH) with three repetitive DNA probes [18S rDNA, (GATA)n and (TTAGGG)n]. Results were very similar in the two species both showing (1) 54 bi-armed chromosomes [submetacentrics (SM) C metacentrics (M) C subtelocentrics (ST)]; (2) 10 terminal NORs after sequential application of rDNA FISH and silver staining; (3) uniform DNA fluorescence with CMA3 and DAPI staining and (4) genomic composition considerably enriched both in highly- and moderately-repeated DNAs. The telomeric (TTAGGG)n sequence hybridized with the termini of all of the chromosomes in the two species. In spite of their apparent karyological uniformity, flow cytometry DNA assays showed that C. aspersus and C. mazzullii are characterized by different nuclear DNA content (C values are 3.58 and 3.08 pg, respectively) and slightly different base composition in their genomes. Present data on GS and AT% in C. mazzullii and C. aspersus confirm the trend toward high GS values and GC percentages among land snails. q 2005 Elsevier Ltd. All rights reserved.

10.1016/j.micron.2004.12.010https://pubmed.ncbi.nlm.nih.gov/15857774