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Vol. 95, No. 1-2, 2001
Issue release date: 2001
Cytogenet Cell Genet 95:73–78 (2001)
(DOI:10.1159/000057020)

XX:XY sex chromosome system with X heterochromatinization: an early stage of sex chromosome differentiation in the Neotropic electric eel Eigenmannia virescens

de Almeida-Toledo L.F. · Foresti F. · Péquignot E.V. · Daniel-Silva M.F.Z.
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Abstract

An early stage of sex chromosome differentiation is reported to occur in the electric eel Eigenmannia virescens (Pisces, Sternopygidae) from populations of two tributaries of the Paraná river system (Brazil). Cytogenetic studies carried out in the two populations showed that the Mogi-Guaçu population is characterized by 2n = 38 chromosomes and undifferentiated sex chromosomes and the Tietê population presents 2n = 38 both for males and females and an XX:XY sex chromosome system. The X-chromosome is acrocentric, easily recognized by the presence of a conspicuous heterochromatin block in its distal portion; the Y-chromosome is probably one of the medium sized acrocentrics present in the male karyotype. BrdU induced R-bands of the two populations did not reveal any difference in the euchromatic regions of the chromosomes. AluI and HaeIII restriction enzyme digestion patterns and chromomycin A3 staining of the X-chromosome are presented. The possible role of heterochromatinization in the evolution of sex chromosomes in fish is discussed.   



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References

  1. Almeida-Toledo LF, Foresti F, Daniel MFZ, Toledo-Filho SA: Sex chromosome evolution in fish: the formation of the neo-Y chromosome in Eigenmannia (Gymnotiformes). Chromosoma 109:197–200 (2000a).
  2. Almeida-Toledo LF, Daniel-Silva MFZ, Lopes CE, Toledo-Filho SA: Sex chromosome evolution in fish. II. Second occurrence of an X1X2Y sex chromosome system in Gymnotiformes. Chrom Res 8:335–340 (2000b).
  3. Almeida-Toledo LF, Foresti F: Morphologically differentiated sex chromosomes in neotropical freshwater fish. Genetica 111:1–3 (2001).
  4. Andreata AA, Almeida-Toledo LF, Oliveira C, Toledo-Filho SA: Chromosome studies in Hypoptopomatinae (Pisces, Siluriformes, Loricariidae): I. XX/XY sex chromosome heteromorphism in Pseudotocinclus tietensis. Cytologia 57:369–372 (1992).
  5. Andreata AA, Almeida-Toledo LF, Oliveira C, Toledo-Filho SA: Chromosome studies in Hypoptopomatinae (Pisces, Siluriformes, Loricariidae). II. ZZ/ZW sex chromosome system, B chromosomes and constitutive heterochromatin differentiation in Microlepidogaster leucofrenatus. Cytogenet Cell Genet 63:215–220 (1993).

    External Resources

  6. Artoni RF: Citogenética do sistema de cromossomos sexuais ZZ/ZW no gênero Triportheus (Pisces, Characidae). PhD Thesis. Universidade Federal de São Carlos, SP (1999).
  7. Artoni RF, Venere PC, Bertollo LAC: A heteromorphic ZZ/ZW sex chromosome system in fish, genus Hypostomus (Loricariidae). Cytologia 63:421–425 (1998).
  8. Bertollo LAC, Cavallaro ZI: A highly differentiated ZZ/ZW sex chromosome system in a Characidae fish, Triportheus guentheri. Cytogenet Cell Genet 60:60–63 (1992).

    External Resources

  9. Born GG, Bertollo LAC: An XX/XY sex chromosome system in a fish species, Hoplias malabaricus, with a polymorphic NOR-bearing chromosome. Chrom Res 8:111–118 (2000).
  10. Brown KE, Guest SS, Smale ST, Hahm K, Merkenschlager M, Fisher AG: Association of transcriptionally silent genes with Ikaros complexes at centromeric heterochromatin. Cell 91:845–854 (1997).
  11. Cuevas CC, Formas JR: Heteromorphic sex chromosomes in Eupsophus insularis (Amphibia, Anura, Leptodactylidae). Chrom Res 4:467–470 (1996).
  12. Falcão JN: Caracterização cariotípica em peixes do gênero Triporteus (Teleostei, Characiformes, Characidae). PhD Thesis, Universidade de São Paulo (1988).
  13. Feldberg E, Bertollo LAC, Almeida-Toledo LF, Foresti F, Moreira-Filho O, Santos AF: Biological aspects of Amazonian fishes. IX. Cytogenetic studies in two species of the genus Semaprochilodus (Pisces, Characidae). Genome 29:1–4 (1987).
  14. Galetti PM Jr, Foresti F, Bertollo LAC, Moreira-Filho O: Heteromorphic sex chromosomes in three species of the genus Leporinus (Pisces, Anostomidae). Cytogenet Cell Genet 29:138–142 (1981).

    External Resources

  15. Galetti PM Jr, Foresti F: Evolution of the ZZ/ZW system in Leporinus (Pisces, Anostomidae). Role of constitutive heterochromatin. Cytogenet Cell Genet 43:43–46 (1986).
  16. Galetti PM Jr, Foresti F: Two new cases of ZZ/ZW heterogamety in Leporinus (Anostomidae, Characiformes) and their relationships in the phylogeny of the group. Rev Brasil Genet X:135–140 (1987).
  17. Haaf T, Schmid M: An early stage of sex chromosome differentiation in Poecilia sphenops var melanistica (Poeciliidae, Cyprinodontiformes). Chromosoma 89:37–41 (1984).
  18. Howell WM, Black DA: Controlled silver-staining of nucleolus organizer regions with a protective colloidal developer: a 1-step method. Experientia 36:1014–1015 (1980).
  19. ISCN (1978): An international system for human cytogenetic nomenclature. Cytogenet Cell Genet 21:309–404 (1980).
  20. Moreira-Filho O, Bertollo LAC, Galetti PM Jr: Distribution of sex chromosomes mechanisms in Neotropical fish and description of a ZZ/ZW system in Parodon hilarii (Parodontidae). Caryologia 46:115–125 (1993).
  21. Molina WF, Schmid M, Galetti PM Jr: Heterochromatin and sex chromosomes in the Neotropical fish genus Leporinus (Characiformes, Anostomidae). Cytobios 94:141–149 (1998).
  22. Nanda I, Feichtinger W, Schmid M, Schröder H, Zischler H, Epplen JT: Simple repetitive sequences
  23. are associated with differentiation of the sex chromosomes in the guppy fish. J Mol Evol 30:456–462 (1990).
  24. Nanda I, Schartl M, Epplen JT, Feichtinger W, Schmid M: Primitive sex chromosomes in Poeciliid fishes harbor simple repetitive DNA sequences. J exp Zool 265:301–308 (1993).
  25. Nanda I, Volff JN, Weis S, Körting C, Froschauer A, Schmid M, Schartl M: Amplification of a long terminal repeat-like element on the Y chromosome of the platyfish, Xiphophorus maculatus. Chromosoma 109:173–180 (2000).
  26. Oliveira C: Síntese dos estudos citogenéticos em peixes neotropicais. Resumos do VIII Simpósio de Citogenética Evolutiva e Aplicada de Peixes Neotropicais, p 108 (2000).
  27. Schaefer SA: Conflict and resolution: impact of the new taxa on phylogenetic studies of the Neotropical Cascudinhos (Siluroidei: Loricariidae), in Malabarba LR, Reis RE, Vari RP, Lucena ZMS, Lucena CAS (eds.): Phylogeny and Classification of Neotropical Fishes, pp 375–400 (Edipucrs, Porto Alegre 1998).
  28. Schmid M: Chromosome banding in amphibia. IV. Differentiation of GC- and AT-rich chromosome regions in Anura. Chromosoma 77:83–103 (1980).
  29. Schmid M, Steinlein C, Feichtinger W, Almeida CG, Duellman WE: Chromosome banding in amphibia. XIII. Sex chromosomes, heterochromatin and meiosis in marsupial frogs (Anura, Hylidae). Chromosoma 97:33–42 (1988).
  30. Sola L, Rossi AR, Iaselli V, Rasch EM, Monaco PJ: Cytogenetics of bisexual/unisexual species of Poecilia. II. Analysis of heterochromatin and nucleolus organizer regions in Poecilia mexicana mexicana by C-banding and DAPI, quinacrine, chromomycin A3, and silver staining. Cytogenet Cell Genet 60:226–235 (1992).
  31. Sumner AT: A simple technique for demonstrating centromeric heterochromatin. Exp Cell Res 75:304–306 (1972).
  32. Vari RP, Malabarba LR: Neotropical ichthyology: an overview, in Malabarba LR, Reis RE, Vari RP, Lucena ZMS, Lucena CAS (eds): Phylogeny and Classification of Neotropical Fishes, pp 1–11 (Edipucrs, Porto Alegre 1998).


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