Germ cell restriction and regular transmission of an accessory chromosome that mimics a sex body in the zebra finch, Taeniopygia guttata

Abstract

Mitotic and meiotic analysis with light and electron microscopy was performed in male and female zebra finches (Taeniopygia guttata). Somatic cells from bone marrow have a 2n = 80 and show the usual sex chromosome mechanism of birds ZZ (male)/ZW (female). In the germ lines of both sexes, a single accessory chromosome was regularly present in all the cells examined from all the individual birds. In synaptonemal complex (SC) spreads of pachytene oocytes and spermatocytes, this accessory chromosome forms a single axis, but it behaves differentially in male and female meiosis. While this accessory chromosome is euchromatic in oocytes, it is strongly heterochromatic in spermatocytes. In pachytene spermatocytes, the accessory chromosome adopts a morphology strikingly similar to that of the XY body (‘sex vesicle’) of mammalian spermatocytes. This accessory chromosome is eliminated during male meiosis and forms a cytoplasmic dense body in young spermatids that shows strong fluorescence with DAPI. The presence of this germ line-restricted chromosome does not affect the behaviour of the ZW pair in oocytes, as the sex chromosomes pair regularly and show a localized recombination nodule. It is suggested that this accessory chromosome has transcriptional activity during oogenesis, and thus it is regularly transmitted through preferential segregation during female meiosis.

This is a preview of subscription content, access via your institution.

References

  1. Capanna E, Civitelli MV, Martinico E (1987) I cromosomi degli uccelli, citotassonomia ed evoluzione cariotipica. Avocetta 11: 101–143.

    Google Scholar 

  2. Cooper A, Penny D (1997) Mass survival of birds across the cretaceous—tertiary boundary: molecular evidence. Science 275: 1109–1112.

    Google Scholar 

  3. De Boer LEM (1984) New developments in vertebrate cytotaxonomy. VIII. A current list of references on avian karyology. Genetica 65: 3–37.

    Google Scholar 

  4. Evans EP, Breckon G, Ford CE (1964) An air-drying method for meiotic preparations from mammalian testes. Cytogenetics 3: 289–294.

    Google Scholar 

  5. Howell WM, Black DA (1980) Controlled silver staining of nucleolus organizing regions with a protective coloidal developer: a 1-step method. Experientia 36: 1014–1015.

    Google Scholar 

  6. Ishak B, Jafaar H, Maetz JL, Rumpler Y (1991) Absence of transcriptional activity of B-chromosomes of Apodemus peninsulae during pachytene. Chromosoma 100: 278–281.

    Google Scholar 

  7. Jones RN, Rees H (1982) B-chromosomes. London: Academic Press.

    Google Scholar 

  8. Kaelbling M, Fechheimer NS (1983) Synaptonemal complexes and the chromosome complement of the domestic fowl, Gallus domesticus. Cytogenet Cell Genet 35: 87–92.

    Google Scholar 

  9. Moses MJ (1977) Synaptonemal complex karyotyping in spermatocytes of the Chinese hamster (Cricetulus griseus). I. Morphology of the autosomal complement in spread preparations. Chromosoma 60: 99–125.

    Google Scholar 

  10. Moses MJ, Poorman PA, Roderick TH, Davisson MT (1982) Synaptonemal complex analysis of mouse chromosomal rearrangements. IV. Synapsis and synaptic adjustment in two paracentric inversions. Chromosoma 84: 454–474.

    Google Scholar 

  11. Ogawa A, Solovei I, Hutchison N, Saitoh Y, Ikeda J, Macgregor H, Mizuno S (1997) Molecular characterization and cytological mapping of a non-repetitive DNA sequence region from the W chromosome of chicken and its use as a universal probe for sexing Carinatae birds. Chrom Res 5: 93–101.

    Google Scholar 

  12. Peters A, Plug A, van Vugt M, de Boer P (1997) A drying-down technique for the spreading of mammalian meiocytes from the male and female germline. Chrom Res 5: 66–71.

    Google Scholar 

  13. Pollock DL, Fechheimer NS (1978) The chromosomes of cockerels during meiosis. Cytogenet Cell Genet 21: 267–281.

    Google Scholar 

  14. Rahn MI, Solari AJ (1986) Recombination nodules in the oocytes of the chicken, Gallus domesticus. Cytogenet Cell Genet 43: 187–193.

    Google Scholar 

  15. Sibley CG, Ahlquist JE (1990) Phylogeny and Classification of Birds. A Study in Molecular Evolution. Yale University Press. New Haven.

  16. Solari AJ (1974) The behavior of the XY pair in mammals. Int Rev Cytol 38: 273–317.

    Google Scholar 

  17. Solari AJ (1977) Ultrastructure of the synaptic autosomes and the ZW bivalent in chicken oocytes. Chromosoma 64: 155–165.

    Google Scholar 

  18. Solari AJ, Fechheimer NS, Bitgood JJ (1988) Pairing of ZW gonosomes and the localized recombination nodule in two Z-autosome translocations in Gallus domesticus. Cytogenet Cell Genet 48: 130–136.

    Google Scholar 

  19. Solari AJ (1989) Sex chromosome pairing and fertility in the heterogametic sex of mammals and birds. In: Gillies CB, ed. Fertility and Chromosome Pairing: Recent Studies in Plants and Animals. Boca Raton: CRC Press, pp 78–107.

    Google Scholar 

  20. Solari AJ (1993) Sex Chromosomes and Sex Determination in Vertebrates. CRC Press: Boca Raton.

    Google Scholar 

  21. Solari AJ, Pigozzi MI (1993) Recombination nodules and axial equalization in the ZW pairs of the Peking duck and the Guinea fowl. Cytogenet Cell Genet 64: 268–272.

    Google Scholar 

  22. Solovei I, Gaginskaya E, Hutchison N, Macgregor H (1993) Avian sex chromosomes in the lampbrush form: the ZW lampbrush bivalents from six species of birds. Chrom Res 1: 153–166.

    Google Scholar 

  23. Switonski M, Gustavsson I, Höjer K, Plöen L (1987) Synaptonemal complex analysis of the B-chromosomes in spermatocytes of the silver fox (Vulpes vulpes Desm.). Cytogenet Cell Genet 45: 84–92.

    Google Scholar 

  24. Tiersch TR, Wachtel SS (1991) On the evolution of genome size in birds. J Hered 82: 363–368.

    Google Scholar 

  25. von Wettstein D, Rasmussen SW, Holm PB (1984) The synaptonemal complex in genetic segregation. Annu Rev Genet 18: 331–413.

    Google Scholar 

Download references

Author information

Affiliations

Authors

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Pigozzi, M.I., Solari, A.J. Germ cell restriction and regular transmission of an accessory chromosome that mimics a sex body in the zebra finch, Taeniopygia guttata. Chromosome Res 6, 105–113 (1998). https://doi.org/10.1023/A:1009234912307

Download citation

  • accessory chromosome
  • meiosis
  • pseudo-sex vesicle
  • synaptonemal complex