, Volume 87, Issue 2, pp 101–106

Occurrence of macro B chromosomes in Astyanax scabripinnis paranae (Pisces, Characiformes, Characidae)

  • E. L. Maistro
  • F. Foresti
  • C. Oliveira
  • L. F. de Almeida Toledo
Research Articles


B chromosomes occur in several Neotropical fish species. Cytogenetic analysis of 27 specimens (15 females and 12 males) of Astyanax scabripinnis paranae from the Araquá river (a small headwater tributary of the Tietê river) shows that this population has 2n=50 chromosomes (4M+30 SM+4ST+12A), two chromosome pairs with NORs and conspicuous C-band positive blocks in the terminal position of the long arm of four chromosome pairs. In this population, eight females presented 2n=51 chromosomes and the extra chromosome was a large metacentric similar in size and morphology to the first chromosome pair in the karotype. This accessory chromosome is entirely heterochromatic in C-banded metaphases and shows a late replication pattern evidenced by BrdU incorporation. There was no significant correlation between the presence of B chromosomes and increased NOR activity at the P>0.05 level. Some aspects related to these B chromosomes are discussed.

Key words

Fish cytogenetics B-chromosomes BrdU-incorporation Astyanax 


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  1. Almeida-Toledo, L. F. & F.Foresti, 1985. As regioes organizadoras do nucléolo em peixes. Ciên. e Cult. 37(3): 448–453.Google Scholar
  2. Almeida-Toledo, L. F., E.Viegas-Péquignot, F.Foresti, S. A.Toledo Filho & B.Dutrillaux, 1988. BrdU replication patterns demonstrating chromosome homoeologies in two fish species, genus Eigenmannia. Cytogenet. Cell Genet. 48: 117–120.Google Scholar
  3. Andreata, A. A., 1991. Estudos citogenéticos na subfamília Hypoptopomatinae (Pisces, Siluriformes, Loricariidae). Master Thesis. Instituto de Biociências, Universidade de São Paulo, 171 pp.Google Scholar
  4. Falcão, J. N., O.Moreira-Filho & L. A. C.Bertollo, 1984. An additional chromosome in two fish species. Rev. Brasil. Genet. 7(1): 109–118.Google Scholar
  5. Foresti, F., L. F.Almeida-Toledo & S. A.Toledo Filho, 1989. Supernumerary chromosome system, C-banding pattern characterization and multiple nucleolus organizer regions in Moenkhausia sanctaefilomenae (Pisces, Characidae). Genetica 79: 107–114.Google Scholar
  6. Howell, W. M. & D. A.Black, 1980. Controlled silver-staining of nucleolus organizer regions with a protective colloidal developer: a 1-step method. Experientia 36: 1014–1015.Google Scholar
  7. ISCN, 1978. An international system for human cytogenetic nomenclature. Cytogenet. Cell Genet. 21: 309–404.Google Scholar
  8. Jones, R. N., 1991. B-Chromosome drive. Am. Nat. 137: 430–442.Google Scholar
  9. Jones, R. N. & H.Rees, 1982. B-chromosomes. New York, Academic Press, 266 pp.Google Scholar
  10. Levan, A., K.Fredga & A. A.Sandberg, 1964. Nomenclature for centromeric position on chromosomes. Hereditas 52: 201–220.Google Scholar
  11. Miller, D. A., W. R.Breg, D.Warburton, V. G.Dev & O. J.Miller, 1978. Regulation of rRNA gene expression in a human familial 14p+ marker chromosome. Hum. Genet. 43: 289–297.Google Scholar
  12. Moreira Filho, O., 1989. Análises cariotipicas e morfológicas sobre a diversidade no ‘complexo’ Astyanax scabripinnis (Jenyns, 1842) (Pisces, Characidae, Tetragonopterinae). Ph.D. Thesis. Universidade Federal de São Carlos, 190 pp.Google Scholar
  13. Moreira Filho, O. & L. A. C.Bertollo, 1991. Astyanax scabripinnis (Pisces, Characidae): a species complex. Rev. Brasil. Genet. 14: 331–357.Google Scholar
  14. Oliveira, C., L. F.Almeida-Toledo, F.Foresti & S. A.Toledo, 1988. Supernumerary chromosomes, Robertsonian rearragement and multiple NORs in Corydoras aeneus (Pisces, Siluriformes, Callichthyidae). Caryologia 41(3–4): 227–236.Google Scholar
  15. Salvador, L. B. & O. Moreira Filho, 1990. Ocorrência de cromossomos B em Astyanax scabripinnis, encontrado em altitudes elevadas. Proc. III Simp. Citogenet. Evol. e Aplic. de Peixes Neotropicais, Botucatu, SP, 14.Google Scholar
  16. Stange, E. R., 1989. Cromossomos supranumerários restritos às células germinativas de machos de Astyanax scabripinnis (Pisces, Characidae). Ciên. Cult. 41: 700.Google Scholar
  17. Sumner, A. T., 1972. A simple technique for demonstrating centromeric heterochromatin. Expl Cell Res. 75: 304–306.Google Scholar
  18. Zar, J. H. 1984. Biostatistical Analysis. 2 ed., Prentice-Hall, Inc., Englewood Cliffs.Google Scholar

Copyright information

© Kluwer Academic Publishers 1992

Authors and Affiliations

  • E. L. Maistro
    • 1
  • F. Foresti
    • 1
  • C. Oliveira
    • 1
  • L. F. de Almeida Toledo
    • 2
  1. 1.Departamento de Morfologia, Instituto de BiociênciasUNESPBotucatuBrazil
  2. 2.Departamento de Biologia, Instituto de BiociênciasUSPSão PauloBrazil

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