A cytogenetic analysis by several staining techniques was carried out on specimens of Seriola dumerili from the Tyrrhenian coast of Sicily. The karyotype was found to be composed of 48 chromosomes in all the specimens examined. All chromosomes are subtelo- and acrocentrics, except for one pair of small-sized submetacentric chromosomes. After Ag-staining, nucleolus organizer regions (NORs) can be observed on the short arms of a medium-sized subtelocentric chromosome pair, and after chromomycin A(3)-staining a bright fluorescent signal is evident at the same sites. The 18S rDNA mapping by fluorescence in situ hybridization confirms this unique NOR location. The constitutive heterochromatin is mainly restricted to centromeres and the fluorochrome-staining by chromomycin A(3) and 4',6-diamidino-2-phenylindole revealed a uniform base composition along the chromosomal arms; therefore stock/population-specific marker chromosomes cannot be identified. Such cytogenetic features, however, rule out the presence of morphologically differentiated sex-chromosomes in the greater amberjack.
Cytogenetic characterization of the greater amberjack, Seriola dumerili (Pisces: Carangidae), by different staining techniques and fluorescence in situ hybridization / Sola, Luciana; O., Cipelli; E., Gornung; Rossi, Anna Rita; F., Andaloro; D., Crosetti. - In: MARINE BIOLOGY. - ISSN 0025-3162. - STAMPA. - 128:4(1997), pp. 573-577. [10.1007/s002270050123]
Cytogenetic characterization of the greater amberjack, Seriola dumerili (Pisces: Carangidae), by different staining techniques and fluorescence in situ hybridization
SOLA, Luciana;ROSSI, Anna Rita;
1997
Abstract
A cytogenetic analysis by several staining techniques was carried out on specimens of Seriola dumerili from the Tyrrhenian coast of Sicily. The karyotype was found to be composed of 48 chromosomes in all the specimens examined. All chromosomes are subtelo- and acrocentrics, except for one pair of small-sized submetacentric chromosomes. After Ag-staining, nucleolus organizer regions (NORs) can be observed on the short arms of a medium-sized subtelocentric chromosome pair, and after chromomycin A(3)-staining a bright fluorescent signal is evident at the same sites. The 18S rDNA mapping by fluorescence in situ hybridization confirms this unique NOR location. The constitutive heterochromatin is mainly restricted to centromeres and the fluorochrome-staining by chromomycin A(3) and 4',6-diamidino-2-phenylindole revealed a uniform base composition along the chromosomal arms; therefore stock/population-specific marker chromosomes cannot be identified. Such cytogenetic features, however, rule out the presence of morphologically differentiated sex-chromosomes in the greater amberjack.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
