6533b854fe1ef96bd12aeaf3

RESEARCH PRODUCT

Repetitive DNAs in the slug Milax nigricans: association of ribosomal (18S–28S and 5S rDNA) and (TTAGGG)n telomeric sequences) in the slug M. nigricans (Mollusca: Gastropoda: Pulmonata)

Nicola VolpeAntonella LanninoMariastella ColombaRoberto VitturiLuca Sineo

subject

MaleSilverNucleolusGeneral Physics and AstronomyBiologyDNA RibosomalBivalent (genetics)Silver stainSpermatocytesStructural BiologyRNA Ribosomal 28SNucleolus Organizer RegionRNA Ribosomal 18SAnimalsGeneral Materials ScienceRepeated sequenceMetaphaseIn Situ Hybridization FluorescenceRepetitive Sequences Nucleic AcidGeneticsBase SequenceStaining and LabelingRNA Ribosomal 5SChromosomeDNACell BiologyTelomereRibosomal RNAMolecular biologyMolluscaNucleolus organizer region

description

Spermatocyte chromosomes of the slug Milax nigricans (Mollusca: Gastropoda: Pulmonata) were studied using silver staining (Ag-NOR) and fluorescent in situ hybridization (FISH) with four repetitive DNA probes [18S rDNA, 5S rDNA, (TTAGGG)n and (GATA)n]. Silver impregnation was inadequate to localize the chromosome sites of nucleolus organizer regions (NORs) since no silver dots occurred on the chromosomes at spermatogonial metaphase and a diffuse silver stainability could be observed on the bivalents at metaphase-I. Unlike silver staining, single-colour rDNA FISH consistently mapped major ribosomal sites (18S-28S rDNA) on two small-sized chromosomes in spermatogonial cells and on the correspondent metaphase-I bivalent in spermatocytes. While telomeric (TTAGGG)n sequence hybridized to all chromosomes, (GATA)n probe localized abundant hybridization sites, dispersed throughout the genome. Simultaneous double-colour FISH demonstrated a close chromosomal association of 18S-28S rDNA, 5S rDNA and (TTAGGG)n.

yearjournalcountryeditionlanguage
2003-07-17Micron
https://doi.org/10.1016/j.micron.2003.11.011