Cytogenetics in the sacoglossan Oxynoe olivacea (Mollusca: Opisthobranchia): karyotype, chromosome banding and fluorescent in situ hybridization
| Autor: | R. Vitturi, Silvano Riggio, Paola Gianguzza, Mariastella Colomba, K. R. Jensen |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Genetics
medicine.medical_specialty Ecology medicine.diagnostic_test Ovotestis biology Cytogenetics Karyotype Aquatic Science biology.organism_classification Molecular biology Oxynoe olivacea medicine Constitutive heterochromatin Nucleolus organizer region Ploidy Ecology Evolution Behavior and Systematics Fluorescence in situ hybridization |
| Zdroj: | Marine Biology. 137:577-582 |
| ISSN: | 1432-1793 0025-3162 |
| DOI: | 10.1007/s002270000377 |
| Popis: | Developing embryos and sexually mature follicles of the male portion of ovotestis proved to be a suitable material as a source of cleaving cells for advanced cytological investigations on the sacoglossan species Oxynoe olivacea Rafinesque, 1819 (Mollusca: Opisthobranchia). O. olivacea has a diploid chromosomal number of 30 made up of 15 pairs of which six are metacentric/submetacentric (M/SM), four subtelocentric (ST) and five on the borderline between SM and ST. Correspondingly, 15 bivalents occur in spermatocytes at Metaphase I. Constitutive heterochromatin is scarce and restricted to small C-bands seen in five pachytene bivalents. The use of combined silver staining and fluorescent in situ hybridization (FISH) with a Paracentrotus lividus (Echinodermata) 4.3 kilobase (kb) rDNA probe (prR14) consisting of sequences from the 3′ end of 18S rDNA to the 3′ end of 26S rDNA, revealed that nucleolus organizer regions (NORs) are situated terminally on one arm of a small metacentric pair. The telomeric (TTAGGG) n sequence did not hybridize with termini of O. olivacea chromosomes. |
| Databáze: | OpenAIRE |
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