Karyotype, location of the nucleolar organizer regions (NORs) and heterochromatin presence and composition were studied in the Antarctic whelk Neobuccinum eatoni. The karyotype exhibits 2n=68 chromosomes with 10 pairs of metacentrics, 14 pairs of meta-submetacentrics, six pairs of submeta-subtelocentrics, and one pair of subtelo-telocentrics. Silver and CMA(3)/ methyl green staining and rDNA FISH evidenced telomeric NORs on the long arm of a pair of medium-sized submetacentrics. Staining with AT-specific fluorochromes evidenced telomeric bands on nearly all chromosomes and interstitial Q bands on two pairs of presumably subtelocentric chromosomes. The karyological evolution of N. eatoni seems to be characterized by a generalized neogastropod karyotype associated with a genome size increase following the accumulation of heterochromatin containing AT-rich repetitive DNA; according to some authors the latter could be related to the modulation of morphological and functional parameters of ecological significance.
The karyology of the Antarctic whelk, Neobuccinum eationi (Mollusca, Neogastropoda) / Odierna, Gaetano; G., Aprea; M., Barucca; A., Canapa; Capriglione, Teresa; E., Olmo. - In: THE ITALIAN JOURNAL OF ZOOLOGY. - ISSN 1125-0003. - STAMPA. - 73:(2006), pp. 303-308. [10.1080/11250000600918076]
The karyology of the Antarctic whelk, Neobuccinum eationi (Mollusca, Neogastropoda)
ODIERNA, GAETANO;CAPRIGLIONE, TERESA;
2006
Abstract
Karyotype, location of the nucleolar organizer regions (NORs) and heterochromatin presence and composition were studied in the Antarctic whelk Neobuccinum eatoni. The karyotype exhibits 2n=68 chromosomes with 10 pairs of metacentrics, 14 pairs of meta-submetacentrics, six pairs of submeta-subtelocentrics, and one pair of subtelo-telocentrics. Silver and CMA(3)/ methyl green staining and rDNA FISH evidenced telomeric NORs on the long arm of a pair of medium-sized submetacentrics. Staining with AT-specific fluorochromes evidenced telomeric bands on nearly all chromosomes and interstitial Q bands on two pairs of presumably subtelocentric chromosomes. The karyological evolution of N. eatoni seems to be characterized by a generalized neogastropod karyotype associated with a genome size increase following the accumulation of heterochromatin containing AT-rich repetitive DNA; according to some authors the latter could be related to the modulation of morphological and functional parameters of ecological significance.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
