Abstract
The chromosomes of the mussel Mytilus galloprovincialis were analysed by means of chromomycin A3 (CMA), distamycin A/DAPI (DA/DAPI), DAPI/actinomycin D (DAPI/AMD) and chromomycin A3/distamycin A/DAPI(CDD) fluorescence banding techniques, C-banding, silver staining, N-banding and in situ hybridization with 18S+28S rDNA and telomere probes. 18S+28S rDNA clusters were located on the telomeres of two pairs of submeta/subtelocentric chromosomes. The nucleolar organizing regions (NORs) were associated with bright CMA fluorescence, dull DAPI fluorescence and C- and N-positive bands, but not all four NOR-associated heterochromatin bands showed bright CMA fluorescence in a given cell; intra- and interindividual variability was found in this character. Additional non-ribosomal C-bands did not show any differential fluorescent behaviour.
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References
Dixon DR, McFadzen IRB (1987) Heterochromatin in the interphase nuclei of the common mussel Mytilus edulis L. J Exp Mar Biol Ecol 112+: 1–9.
Dixon DR, McFadzen IRB, Sisley K (1986) Heterochromatic marker regions (nucleolar organisers) in the chromosomes of the common mussel, Mytilus edulis (Mollusca: Pelecypoda). J Exp Mar Biol Ecol 97: 205–212.
Guttenbach M, Schmid M (1994) Exclusion of specific human chromosomes into micronuclei by 5-azacytidine treatment of lymphocyte cultures. Exp Cell Res 211: 127–132.
Howell WM, Black DA (1980) Controlled silver-staining of nucleolus organizer regions with a protective colloidal developer: a 1-step method. Experientia 36: 1014–1015.
Insua A, Thiriot-Quieévreux C (1991) The characterization of Ostrea denselamellosa (Mollusca, Bivalvia) chromosomes: karyotype, constitutive heterochromatin and nucleolus organizer regions. Aquaculture 97: 317–325.
Jacobi CM, Rosenberg C, Vianna-Morgante AM (1990) The karyotype of the brown mussel Perna perna (L.) (Bivalvia: Mytilidae). Rev Brasil Genet 13: 669–673.
Martínez P, Vinñas A, Bouza C, Castro J, Sánchez L (1993) Quantitative analysis of the variability of nucleolar organizer regions in Salmo trutta. Genome 36: 1119–1123.
Martínez-Expósito MJ, Pasantes JJ, Méndez J (1994) NOR activity in larval and juvenile mussels (Mytilus galloprovincialis Lmk.). J Exp Mar Biol Ecol 175: 155–165.
Martínez-Lage A, Gonzlez-Tizón A, Méndez J (1994) Characterization of different chromatin types in Mytilus galloprovincialis L. after C-banding, fluorochrome and restriction endonuclease treatments. Heredity 72: 242–249.
Martínez-Lage A, González-Tizón A, Méndez J (1995) Chromosomal markers in three species of the genus Mytilus (Mollusca: Bivalvia). Heredity 74: 369–375.
Matsui S, Sasaki M (1973) Differential staining of nucleolus organizers in mammalian chromosomes. Nature 246: 148–150.
Monaco PJ, Rasch EM (1982) Differences in staining with DNA-specific fluorochromes during spermiogenesis. J Histochem Cytochem 30: 585–590.
Moyzis RK, Buckingham JM, Cram LS et al. (1988) A highly conserved repetitive DNA sequence (TTAGGG)n present at the telomeres of human chromosomes. Proc Natl Acad Sci USA 85: 6622–6626.
Pasantes JJ, Martínez-Expósito MJ, Méndez J (1996) C-band polymorphism in the chromosomes of the mussel Mytilus galloprovincialis Lmk. Caryologia, in press. [q1]
Phillips RB, Ihssen PE (1985) Chromosome banding in salmonid fishes: nucleolar organizer regions in Salmo and Savelinus. Can J Genet Cytol 27: 433–440.
Phillips RB, Zajicek KD, Utter FM (1986) Chromosome banding in salmonid fishes: nucleolar organizer regions in Oncorhynchus. Can J Genet Cytol 28: 502–510.
Ruiz IRG, Soma M, Beçak W (1981) Nucleolar organizer regions and constitutive heterochromatin in polyploid species of the genus Odontophrynus (Amphibia, Anura). Cytogenet Cell Genet 29: 84–98.
Sánchez L, Martínez P, Viñas A, Bouza C (1990) Analysis of the structure and variability of nucleolar organizer regions of Salmo trutta by C-, Ag-, and restriction endonuclease banding. Cytogenet Cell Genet 54: 6–9.
Schmid M (1978) Chromosome banding in Amphibia. I. Constitutive heterochromatin and nucleolus organizer regions in Bufo and Hyla. Chromosoma 66: 361–388.
Schmid M (1982) Chromosome banding in Amphibia. VII. Analysis of the structure and variability of NORs in Anura. Chromosoma 87: 327–344.
Schmid M, Guttenbach M, Nanda I, Studer R, Epplen JT (1990) Organization of DYZ2 repetitive DNA on the human Y chromosome. Genomics 6: 212–218.
Schweizer D (1976) Reverse fluorescent chromosome banding with chromomycin and DAPI. Chromosoma 58: 307–324.
Schweizer D (1977) R-banding produced by DNAase I digestion of chromomycin-stained chromosomes. Chromosoma 64: 117–124.
Schweizer D (1980) Simultaneous fluorescent staining of Rbands and specific heterochromatic regions (DA/DAPI bands) in human chromosomes. Cytogenet Cell Genet 27: 190–193.
Schweizer D (1981) Counterstain-enhanced chromosome banding. Hum Genet 57: 1–14.
Sumner AT (1972) A simple technique for demonstrating centromeric heterochromatin. Exp Cell Res 75: 304–306.
Sumner AT (1990) Chromosome Banding. London: Unwin Hyman.
Thiriot-Quiévreux C, Insua A (1992) Nucleolar organiser region variation in the chromosomes of three oyster species. J Exp Mar Biol Ecol 157: 3340.
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Marti´nez-Expo´sito, M.J., Me´ndez, J. & Pasantes, J.J. Analysis of NORs and NOR-associated heterochromatin in the mussel Mytilus galloprovincialis Lmk. Chromosome Res 5, 268–273 (1997). https://doi.org/10.1023/A:1018475804613
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DOI: https://doi.org/10.1023/A:1018475804613