The karyology of the Antarctic whelk, Neobuccinum eationi (Mollusca, Neogastropoda)

• Published in: Italian Journal of Zoology
• Main Authors: ODIERNA, GAETANO, CAPRIGLIONE, TERESA, G. Aprea, M. Barucca, A. Canapa, E. Olmo
• Other Authors: Odierna, Gaetano, G., Aprea, M., Barucca, A., Canapa, Capriglione, Teresa, E., Olmo
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2006
• Subjects: chromosome; chromosome banding; Neobuccinum eatoni; Gastropoda; Antarctica; Antarctic; The Antarctic; Long Arm; Antarc*
• Online Access: http://hdl.handle.net/11588/464722; https://doi.org/10.1080/11250000600918076

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.