Chromosome Research

, Volume 14, Issue 6, pp 665–672 | Cite as

Genome size, karyotype, meiosis and a novel extra chromosome in Torenia fournieri, T. baillonii and their hybrid

  • S. Kikuchi
  • H. Tanaka
  • T. Shiba
  • M. Mii
  • H. Tsujimoto
Article

Abstract

Torenia is a suitable model plant to study plant fertilization because of its protruding embryo sac. However, information on the genomes and chromosomes of this species is limited. We determined the genome sizes of T. fournieri Linden and T. baillonii Godefr as 1.71 pg × 108 bp and 1.67 × 108 bp, respectively. The small genome size of these species suggests their superiority as the targets for molecular cloning studies. Furthermore, karyotypes of T. fournieri and T. baillonii were determined using FISH probed with 5S rDNA, 45S rDNA and species-specific centromere repetitive sequences. Although the two species have similar genome size, number of chromosomes, centromere repeats and 5S rDNA loci were varied. Observation of meiosis in the F1 hybrid revealed that all chromosomes except one of T. fournieri paired well with the chromosomes of T. baillonii throughout the entire length of the chromosomes including species-specific centromeric regions. One exceptional chromosome of T. fournieri behaved as a univalent and was not always required for gametogenesis. The present results provide the basis for the molecular genetics in Torenia.

Key words

chromosome pairing extra chromosome genome size karyotype Torenia 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Aida R, Shibata M (1995) Agrobacterium-mediated transformation of Torenia (Torenia fournieri). Breed Sci 45: 71–74.Google Scholar
  2. Arumuganathan K, Earle ED (1991) Nuclear DNA content of some important plant species. Plant Mol Biol Rep 9: 208–218.Google Scholar
  3. Bedaeva ED, Friebe B, Gill BS (1996) Genome differentiation in Aegilops. 2. Physical mapping of 5S and 18S–26S ribosomal RNA gene families in diploid species. Genome 39: 1150–1158.Google Scholar
  4. Bennett MD, Leitch IJ, Price HJ, Johnston JS (2003) Comparisons with Caenorhabditis (∼100 Mb) and Drosophila (∼175 Mb) using flow cytometry show genome size in arabidopsis to be ∼157 Mb and thus ∼25% larger than the Arabidopsis Genome Initiative of ∼125 Mb. Ann Bot (Lond) 91: 1–11.Google Scholar
  5. Cheng RIJ, Grant WF (1973) Species relationships in the Lotus corniculatus group as determined by karyotype and cytophotometric analyses. Canad J Genet Cytol 15: 101–115.Google Scholar
  6. Dolezel J, Bartos J, Voglmayr H, Greilhuber J (2003) Nuclear DNA content and genome size of trout and human. Cytometry A51: 127–128.CrossRefGoogle Scholar
  7. Fukui K, Kamisugi Y, Sakai F (1994) Physical mapping of 5S rDNA loci by direct-cloned biotinylated probes in barley chromosomes. Genome 37: 105–111.PubMedGoogle Scholar
  8. Heslop-Harrison JS, Murata M, Ogura Y, Schwarzacher T, Motoyoshi F (1999) Polymorphisms and genomic organization of repetitive DNA from centromeric regions of Arabidopsis chromosomes. Plant Cell 11: 31–42.PubMedCrossRefGoogle Scholar
  9. Higashiyama T, Kuroiwa H, Kawano S, Kuroiwa T (1998) Guidance in vitro of the pollen tube to the naked embryo sac of Torenia fournieri. Plant Cell 10: 2019–2031.PubMedCrossRefGoogle Scholar
  10. Higashiyama T, Yabe S, Sasaki N et al. (2001) Pollen tube attraction by the synergid cell. Science 293: 1480–1483.PubMedCrossRefGoogle Scholar
  11. Jones RN, Rees H (1982) B Chromosomes, 1st edn. New York: Academic Press.Google Scholar
  12. Kikuchi S, Kishii M, Shimizu M, Tanaka H, Tsujimoto H (2005) Centromere-specific repetitive sequences from Torenia, a model plant for interspecific fertilization, and whole-mount FISH of its interspecific hybrid embryos. Cytogenet Genome Res 109: 228–235.PubMedCrossRefGoogle Scholar
  13. Lee HR, Zhang W, Langdon T et al. (2005) Chromatin immunoprecipitation cloning reveals rapid evolutionary patterns of centromeric DNA in Oryza species. Proc Natl Acad Sci USA 102: 11793–11798.PubMedCrossRefGoogle Scholar
  14. Mishiba K, Ando T, Mii M et al. (2000) Nuclear DNA contents as an index character discriminating taxa in the genus Petunia sensu Jussieu (Solanaceae). Ann Bot (Lond) 85: 665–673.CrossRefGoogle Scholar
  15. Mishima M, Ohmido N, Fukui K, Yahara T (2002) Trends in site-number change of rDNA loci during polyploid evolution in Sanguisorba (Rosaceae). Chromosoma 110: 550–558.PubMedGoogle Scholar
  16. Naranjo T, Corredor E (2004) Clustering of centromeres precedes bivalent chromosome pairing of polyploid wheats. Trends Plant Sci 9: 214–217.PubMedCrossRefGoogle Scholar
  17. Taketa S, Ando H, Takeda K, Ichii M, von Bothemer R (2005) Ancestry of American polyploid Hordeum species with the I genome inferred from 5S and 18S–25S rDNA. Ann Bot (Lond) 96: 23–33.CrossRefGoogle Scholar
  18. Tsubouchi T, Roeder GS (2005) A synaptonemal complex protein promotes homology-independent centromere coupling. Science 308: 870–873.PubMedCrossRefGoogle Scholar

Copyright information

© Springer 2006

Authors and Affiliations

  • S. Kikuchi
    • 1
  • H. Tanaka
    • 1
  • T. Shiba
    • 2
    • 3
  • M. Mii
    • 2
  • H. Tsujimoto
    • 1
  1. 1.Laboratory of Plant Genetics and Breeding Science, Faculty of AgricultureTottori UniversityTottoriJapan
  2. 2.Plant Cell Technology Laboratory, Faculty of HorticultureChiba UniversityChibaJapan
  3. 3.Plant Biotechnology DepartmentNational Institute of Agrobiological Sciences (NIAS)TsukubaJapan

Personalised recommendations