Chromosome Research

, Volume 8, Issue 8, pp 737–746 | Cite as

Gene density in the Giemsa bands of human chromosomes

  • Concetta Federico
  • Letizia Andreozzi
  • Salvatore Saccone
  • Giorgio Bernardi


The human genome is formed by isochores belonging to five families, L1, L2, H1, H2 and H3, that are characterized by increasing GC levels and gene concentrations. In-situ hybridization of DNA from different isochore families provides, therefore, information not only on the correlation between isochores and chromosomal bands, but also on the distribution of genes in chromosomes. Three subsets of R(everse) bands were identified: H3+, H3* and H3, that contain large, moderate, and no detectable amounts, respectively, of the gene-richest H2 and H3 isochores, and replicate very early and early, respectively, in S phase of the cell cycle. Here, we investigated the GC levels, replication timings and DNA compaction of G(iemsa) bands. We showed that G bands comprise two different subsets of bands, one of which is predominantly composed of L1 isochores, replicates at the end of the S phase, has a higher DNA compaction relative to H3+ bands and corresponds to the darkest G bands of Francke (1994). In contrast, the other subset is composed of L2 and H1 isochores, has less-extreme properties in replication and composition and corresponds to the less-dark G bands of Francke.

chromatin condensation human genome in-situ hybridization isochores replication timing 


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  1. Bernardi G (1995) The human genome: organization and evolutionary history. Ann Rev Genet 29: 445–476.PubMedCrossRefGoogle Scholar
  2. Bernardi G (2000) Isochores and the evolutionary genomics of vertebrates. Gene 241: 3–17.PubMedCrossRefGoogle Scholar
  3. Bernardi G, Olofsson B, Filipski J et al. (1985) The mosaic genome of warm-blooded vertebrates. Science 228: 953–958.PubMedGoogle Scholar
  4. Biemont MC, Laurent C, Couturie J, Dutrillaux B (1978) Chronologie de la rëplication des bandes des chromosomes sexuels dans les lymphocytes de sujets normaux et anormaux. Ann Gënët 21: 133–141.PubMedGoogle Scholar
  5. Craig JM, Bickmore WA (1994) The distribution of CpG islands in mammalian chromosomes. Nature Genet 7: 376–382.PubMedCrossRefGoogle Scholar
  6. Cuny G, Soriano P, Macaya G, Bernardi G (1981) The major components of the mouse and human genomes: preparation, basic properties and compositional heterogeneity. Eur J Biochem 111: 227–233.CrossRefGoogle Scholar
  7. Drouin R, Lemieux N, Richer C-L (1990) Analysis of DNA replication during S-phase by means of dynamic chromo-some banding at high resolution. Chromosoma 99: 273–280.PubMedCrossRefGoogle Scholar
  8. Drouin R, Holmquist G, Richer CL (1994) High resolution replication bands compared with morphologic G-and R-bands. Adv Hum Genet 22: 47–115.PubMedGoogle Scholar
  9. Dunham I, Shimizu N, Roe BA et al. (1999) The DNA sequence of human chromosome 22. Nature 402: 489–495.PubMedCrossRefGoogle Scholar
  10. Dutrillaux B (1973) Nouveau système de marquage chromosomique: les bandes T. Chromosoma 41: 395–402.PubMedCrossRefGoogle Scholar
  11. Dutrillaux B, Couturier J, Richer C-L, Viegas-Pequinot E (1976) Sequence of DNA replication in 277 R-and Q-bands of human chromosomes using a BrdU treatment. Chromosoma 58: 51–61.PubMedCrossRefGoogle Scholar
  12. Federico C, Saccone S, Bernardi G (1998) The gene-richest bands of human chromosomes replicate at the onset of the S-phase. Cytogenet Cell Genet 80: 83–88.PubMedCrossRefGoogle Scholar
  13. Fetni R, Drouin R, Richer C-L, Lemieux N (1996) Complementary replication R-and G-band patterns induced by cell blocking at the R-band/G-band transition, a possible regulatory checkpoint within the S phase of the cell cycle. Cytogenet Cell Genet 75: 172–179.PubMedGoogle Scholar
  14. Francke U (1994) Digitized and differentially shaded human chromosome ideograms for genomic applications. Cytogenet Cell Genet 6: 206–219.CrossRefGoogle Scholar
  15. Hattori M, Fujiyama A, Taylor TD et al. (2000) The DNA sequence of human chromosome 21. Nature 405: 311.PubMedCrossRefGoogle Scholar
  16. Kim MA, Johannsmann R, Grzeschik K-H (1975) Giemsa staining of the sites replicating DNA early in human lymphocyte chromosomes. Cytogenet Cell Genet 15: 363–371.PubMedGoogle Scholar
  17. Mouchiroud D, D'Onofrio G, Aïssani B, Macaya G, Gautier C, Bernardi G (1991) The distribution of genes in the human genome. Gene 100: 181–187.PubMedCrossRefGoogle Scholar
  18. Saccone S, De Sario A, Della Valle G, Bernardi G (1992) The highest gene concentrations in the human genome are in T-bands of metaphase chromosomes. Proc Natl Acad Sci USA 89: 4913–4917.PubMedCrossRefGoogle Scholar
  19. Saccone S, De Sario A, Wiegant J, Raap AK, Della Valle G, Bernardi G (1993) Correlations between isochores and chromosomal bands in the human genome. Proc Natl Acad Sci USA 90: 11929–11933.PubMedCrossRefGoogle Scholar
  20. Saccone S, Cacciò S, Kusuda J, Andreozzi L, Bernardi G (1996) Identification of the gene-richest bands in human chromosomes. Gene 174: 85–94.PubMedCrossRefGoogle Scholar
  21. Saccone S, Federico C, Solovei I, Croquette MF, Della Valle G, Bernardi G (1999) Identification of the gene-richest bands in human prometaphase chromosomes. Chromosome Res 7: 379–386.PubMedCrossRefGoogle Scholar
  22. Vogel W, Autenrieth M, Mehnert K(1989) Analysis of chromosome replication by a BrdU antibody technique. Chromosoma 98: 335–341.PubMedCrossRefGoogle Scholar
  23. Zoubak S, Clay O, Bernardi G (1996) The gene distribution of the human genome. Gene 174: 95–102.PubMedCrossRefGoogle Scholar

Copyright information

© Kluwer Academic Publishers 2000

Authors and Affiliations

  • Concetta Federico
    • 1
  • Letizia Andreozzi
    • 1
  • Salvatore Saccone
    • 1
    • 2
  • Giorgio Bernardi
    • 3
  1. 1.Dipartimento di Biologia AnimaleUniversity of CataniaCataniaItaly
  2. 2.Dipartimento di Protezione e Valorizzazione AgroalimentareUniversity of BolognaReggio EmiliaItaly
  3. 3.Laboratorio di Evoluzione Molecolare, Stazione ZoologicaNapoliItaly

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