Abstract
Because of their compact genome, pufferfish (Tetraodontiformes) have been proposed as a model for the study of the vertebrate genome. The genome of pufferfish is peculiar as it has the structural complexity of the genomes of higher vertebrates, but has small introns and lacks large clusters of highly repetitive sequences. Despite such interest, information about the genetics of pufferfish is still scanty. To fill this gap, we have performed a cytogenetic analysis of the pufferfish, Tetraodon fluviatilis, which can be maintained in an aquarium for a long time and, unlike the pufferfish, Fugu rubripes, it is not difficult to obtain. Karyotype analysis shows that T. fluviatilis has 2n = 42 with two metacentric chromosomes, four submetacentrics, two subtelocentrics and 34 acrocentrics. C-banding, followed by DAPI staining, showed that heterochromatin is essentially AT-rich and is located at centromeres. Staining of the same metaphase plates with CMA3 showed the presence of four heterochromatic regions located on two pairs of submetacentric chromosomes. Silver staining and FISH with a 28S rDNA probe showed that these GC-rich regions are nucleolar organizing regions (NORs). Finally, regardless of the technique used, no difference in the chromosome complement was found between males and females.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Almeida-Toledo LF, Stocker AJ, Foresti F, Almeida Toledo-Filho S (1996) Fluorescence in situ hybridization with rDNA probes on chromosomes of two nucleolus organizer region phenotypes of a species of Eigenmannia (Pisces, Gymnotoidei, Sternopygidae). Chromosome Res 4: 301–305.
Ameiya CT, Gold JR (1986) Chromomycin A3 stains nucleolus organizer regions of fish chromosomes. Copeia 1986: 226–231.
Ameiya CT, Gold JR (1990) Cytogenetic studies in North American minnows (Cyprinidae). Hereditas 112: 231–247.
Aparicio S, Morrison A, Gould A, et al. (1995) Detecting conserved regulatory elements with the model genome of the Japanese pufferfish Fugu rubripes. Proc Natl Acad Sci USA 92: 1684–88.
Ashley T, Ward DC (1993) A hot spot of recombination coincides with an interstitial telomeric sequence in the Armenian hamster. Cytogenet Cell Genet 62: 169–171.
Baxendale S, Abdulla S, Elgar G, et al. (1995) Comparative sequence analysis of the human and pufferfish Huntington's disease genes. Nat Genet 10: 67–76.
Bradford CS, Miller AE, Toumadje A (1997) Characterization of cell cultures derived from Fugu, the Japanese pufferfish. Mol Mar Biol Biotechnol 4: 279–288.
Brenner S, Elgar G, Sanford R, Macrae A, Venkatesh B, Aparico S (1993) Characterization of the puffer fish (Fugu) genome as a compact model vertebrate genome. Nature 366: 265–268.
Caputo V, Marchegiani F, Olmo E (1996) Karyotype differentiation between two species of the genus Trachurus (Teleostei, Carangidae). Marine Biol 127: 193–199.
Crnogorac-Jurcevic T, Brown JR, Lehrach H, Schalkwyk LC (1997) Tetraodon fluviatilis, a new puffer fish model for genome studies. Genomics 41: 177–184.
Donlon TA, Magenis RE (1983) Methyl green is a substitute for distamycin A in the formation of distamycin A/DAPI C-bands. Hum Genet 65: 144–146.
Elgar G, Sanford R, Aparicio S, Macrae A, Venkatesh B, Brenner S (1996) Small is beautiful: comparative genomics with the puffer-fish (Fugu rubripes). Trends Genet 12: 145–150.
Foresti F, Almeida-Toledo LF, Toledo F (1981) Polymorphic nature of nucleolus organizer regions in fishes. Cytogenet Cell Genet 31: 137–144.
Hinegardner R (1968) Evolution of cellular DNA content in teleost fishes. Am Nat 102: 517–523.
How GF, Venkatesh B, Brenner S (1996) Conserved linkage between the pufferfish (Fugu rubripes) and human genes for platelet-derived growth factor receptor and macrophage colony-stimulating factor receptor. Genome Res 6: 1185–1191.
Howell WM (1977) Visualization of ribosomal gene activity: silver stains proteins associated with rRNA transcribed from oocyte chromosomes. Chromosoma 62: 361–367.
Koop BF, Nadeau JH (1996) Pufferfish and a new paradigm for comparative genome analysis. Proc Natl Acad Sci USA 93: 1363–1365.
Insua A, Mendez J (1998) Physical mapping and activity of ribosomal RNA genes in mussel Mytilus galloprovincialis. Hereditas 128: 189–194.
Levan A, Fredga K, Sandberg AA (1964) Nomenclature for centromeric position on chromosome. Hereditas 52: 201–220.
Maheshwar MM, Sanford R, Nellist M, et al. (1996) Comparative analysis and genomic structure of the tuberous sclerosis 2(TSC2) gene in human and pufferfish. Hum Mol Genet 5: 131–137.
Mandrioli M, Manicardi GC, Bizzaro D, Bianchi U (1999a) NOR heteromorphism within a parthenogenetic lineage of the aphid Megoura viciae. Chromosome Res 7: 157–162.
Mandrioli M, Bizzaro D, Giusti M, Manicardi GC, Bianchi U (1999b) The role of rDNA genes during somatic X chromosomes association in the aphid Acyrthosiphon pisum. Genome 42: 381–386.
Miller OJ, Miller DA, Dev VG, Tantravahi R, Croce CM (1976) Expression of human and suppression of mouse nucleolus organizer activity in mouse-human somatic cell hybrids. Proc Natl Acad Sci USA 73: 4531–4535.
Miyaki K, Tabeta O, Kayano H (1995) Karyotypes in six species of pufferfishes genus Takifugu (Tetraodontidae, Tetraodontiformes). Fisheries Sci 61: 594–598.
Phillips RB, Reed KM (1996) Application of fluorescent in situ hybridization (FISH) techniques to fish genetics: a review. Aquaculture 140: 197–216.
Salvadori S, Deiana AM, Coluccia E, Floridia G, Rossi E, Zuffardi O (1995) Co-localization of (TTAGGG)n telomeric sequences and ribosomal genes in Atlantic eels. Chromosome Res 3: 54–58.
Sanchez A, Burgos M, Jimenez R, Diaz de la Guardia R (1989) Quantitative analysis of silver staining on the nucleolar organizing regions in Eliomys quercinus. Genome 32: 978–982.
Schmid M (1982) Chromosome banding in Amphibia. VII. Analysis of the structure and variability of NORs in Anura. Chromosoma 87: 327–344.
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.
Suzuki H, Kurihara Y, Kanehisa T, Moriwaki K (1990) Variation in the distribution of silver-stained nucleolar organizing regions on the chromosomes of the wild mouse Mus musculus. Mol Biol Evol 7: 271–282.
Zurita F, Sanchez A, Burgos M, Jimenez R, Diaz de la Guardia R (1997) Inter-chromosomal, intercellular and inter-individual variability of NOR studied with silver staining and in situ hybridization. Heredity 78: 229–234.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Mandrioli, M., Cuoghi, B., Marini, M. et al. Cytogenetic Analysis of the Pufferfish Tetraodon Fluviatilis (Osteichthyes). Chromosome Res 8, 237–242 (2000). https://doi.org/10.1023/A:1009257131091
Issue Date:
DOI: https://doi.org/10.1023/A:1009257131091