Population distribution of 45S and 5S rDNA in golden mahseer, Tor putitora: population-specific FISH marker
- 116 Downloads
Chromosomal locations of major 45S and minor 5S ribosomal DNAs (rDNAs) and organization of 5S rRNA genes were analysed in five different populations of golden mahseers (Tor putitora) using fluorescence in situ hybridization (FISH) and Southern blot hybridization. All five populations of T. putitora (2n = 100) showed a similar type of macro-karyotype composed of 12 metacentric, 22 submetacentric, 14 subtelocentric and 52 telocentric chromosomes. Analysis of active nucleolar organizer regions (NORs) by silver staining did not show any differences in number and chromosomal position in different populations. But FISH data showed significant difference between the populations, four of the five populations showed six 18S (three pairs) and two 5S (one pair) signals with positional polymorphism, while one population showed eight 18S and four 5S signals, respectively. Southern blot data confirms that 5S rDNA clusters present on two different chromosome pairs in Kosi river population contain non-transcribed spacers (NTS) of same length. In the present study, simultaneous localization of 45S and 5S rDNA by in situ hybridization helped us to develop the discrete population-specific markers in different geographically isolated populations of T. putitora.
Keywords18S rDNA 5S rDNA FISH rDNA Tor putitora
Unable to display preview. Download preview PDF.
- Bertollo L. A. C., Takahashi C. S. and Moreira-Filho O. 1978 Cytotaxonomic consideration on Hoplias lacrdae (Pisces, Erythrinidae). Braz. J. Genet. 1, 103–120.Google Scholar
- Khuda-Bukhsh A. R. and Nayak K. 1982 Karyomorpological studies in two species of hill stream fishes from Kashmir, India: occurrence of a high number of chromosomes. Chromosome Inf. Sci. 33, 12–14.Google Scholar
- Kushwaha B., Srivastava S. K., Nagpure N. S., Ogale S. N. and Ponniah A. G. 2001 Cytogenetic studies in two species of mahseer, Tor khudree and Tor mussullah (Cyprinidae, Pisces) from India. Chromosome Sci. 5, 47–50.Google Scholar
- Lakra W. S. 1996 Cytogenetic studies on endangered fish species: karyotypes of three species of mahseers, Tor putitora, T. tor and T. khudree (Cyprinidae Pisces). Cytobios 85, 205–218.Google Scholar
- Martins C. and Wasko A. P. 2004 Organization and evolution of 5S ribosomal DNA in the fish genome. In Focus on genome research (ed. C. R. Williams), pp. 289–319. Nova Science Publishers, New York, USA.Google Scholar
- Miklos G. L. G. 1985 Localized highly repetitive DNA sequences in vertebrates and invertebrates genomes. In Molecular evolutionary genetics (ed. R. J. MacIntyre), pp. 241–321. Plenum Press, New York, USA.Google Scholar
- Sambrook J. and Russell I. 2001 Molecular cloning: a laboratory manual, 3rd edition. Cold Spring Harbor Laboratory Press, Plainsveiw, New York, USA.Google Scholar