Open AccessChromosome analysis using different staining techniques and fluorescent in situ hybridization in Cerithium vulgatum (Gastropoda: Cerithiidae)
Author(s) -
VITTURI R.,
COLOMBA M.,
CASTRIOTA L.,
BELTRANO A. M.,
LANNINO A.,
VOLPE N.
Publication year - 2002
Publication title -
hereditas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 50
eISSN - 1601-5223
pISSN - 0018-0661
DOI - 10.1034/j.1601-5223.2002.01631.x
Subject(s) - biology , chromosome , karyotype , fluorescence in situ hybridization , dapi , ribosomal rna , microbiology and biotechnology , genetics , population , ribosomal dna , staining , phylogenetic tree , gene , demography , sociology
In the present paper one population of the “large” subtidal mollusc Cerithium vulgatum Bruguière, 1792 (Gastropoda: Cerithiidae) from the Northwestern coast of Sicily was investigated from a karyological point of view. The chromosome complement was Giemsa stained, conventionally karyotyped in 18 homomorphic chromosome pairs (10 bi‐armed and 8 mono‐armed), and subsequently analysed using silver, CMA 3 and DAPI staining, and fluorescent in situ hybridization (FISH) with three repetitive DNA probes [ribosomal DNA (rDNA), (TTAGGG) n and (GATA) n ]. FISH with the rDNA probe consistently mapped major ribosomal sites (18S‐28S rDNA) in the terminal region of the short arms of one small sized mono‐armed chromosome pair. Ribosomal DNA was transciptionally active as indicated by its preferential impregnation with silver nitrate (Ag‐NOR) and did not contain a high amount of GC base pairs as suggested by the lack of a bright CMA 3 fluorescence. The (TTAGGG) n telomeric probe was hybridized to the termini of nearly all chromosomes, thus demonstrating that, in C. vulgatum , this sequence has been conserved during the genomic evolution. The finding of the telomeric hexanucleotide in six species belonging to the three high taxa of Gastropoda supports the notion that this sequence is widespread within this class. The (GATA) n probe did not label any chromosome regions except for a minute terminal area of a single bivalent at pachytene stage.