Nucleotide sequences of the internal transcribed spacers and 5.8S rRNA genes fromAlaria marginataandPostelsia palmaeformis(Phaeophyta: Laminariales)

✍ Scribed by G. W. Saunders; L. D. Druehl

• Publisher: Springer-Verlag
• Year: 1993
• Tongue: English
• Weight: 664 KB
• Volume: 115
• Category: Article
• ISSN: 0025-3162
• DOI: 10.1007/bf00349831

✦ Synopsis

Nucleotide sequences have been determined for the 5.8S ribosomal RNA (rRNA) gene, and the first and second internal transcribed spacers (ITS1 and ITS2, respectively), for representatives of the two phaeophycean genera Alaria and Postelsia, of the order Laminariales (kelp). These regions of the ribosomal cistron were remarkably conserved between these two morphologically diverse taxa. The phaeophycean-derived ITS regions were similar in length to those of green plants and fungi, but only similar to the former in G + C content. The phenomenon of G + C balance was exhibited for the ITS1 and ITS2 of P. palmaeformis Ruprecht, but less so for these spacers in A. marginata Postels and Ruprecht. Putative stem-loops, possibly involved in post-transcriptional processing, have been identified for these two phaeophycean taxa in a conserved region immediately upstream (5') from the 5.8S gene. Phylogenetic relationships of the kelps relative to animals, plants and fungi could not be resolved with the 5.8S gene sequence.