| Přispěvatelé: |
Rocco, Lucia, Russo, C., Stingo, Vincenzo, Aprea, G., Odierna, G. |
| Popis: |
The 5S rRNA genes of Gasterosteus aculeatus were characterised. Genomic DNA was amplified by PCR using two primers constructed in different salmonid species in order both to extract the total 5S rDNA (coding region + nontranscribed spacer region) and to generate amplified DNA products only if 5S rDNAs were tandemly arrayed. Amplification revealed four bands (A, B, C, and D) of about 250, 370, 580, and 660 base pairs, respectively. The electrophoretic pattern yielded by PCR products appeared very similar in the various species examined, it was also present in a selachian, an amphibian and a reptile. However, differences were observed in the size of the bands. Band A was cloned and se‐quenced: it consisted of 225 base pairs (A+T = 48.6%; G+C = 51.4%) and showed a high sequence homology to 5S rDNA in many vertebrate species. Hybridization on nylon filters of genomic DNA digested with several restriction enzymes showed the typical tandem array of repeated DNAs. |
