Vol. 39 No. 2, 2000
The ETS/IGS Region in a Lower Animal, the Seawhip, Junceella fragilis
(Cnidaria: Anthozoa: Octocorallia): Compactness, Low Variation and
Apparent Conservation of a Pre-rRNA Processing Signal with Fungi
Chaolun Allen Chen1,* David J. Miller2, Nuwei Vivian Wei1,3,4, Chang-Feng Dai3 and Hsiao-Pei Yang3
1Institute of Zoology, Academia Sinica, Nankang, Taipei, Taiwan 115
2Department of Biochemistry and Molecular Biology, James Cook University, Townsville, Queensland 4811, Australia
3Institute of Oceanography, National Taiwan University, Taipei, Taiwan 106
4Department of Biology, Chinese Culture University, Taipei, Taiwan 111
Chaolun Allen Chen, David J. Miller, Nuwei Vivian Wei, Chang-Feng Dai and Hsiao-Pei Yang (2000)
We determined the nucleotide sequence of an atypically short intergenic
spacer/external transcribed spacer (IGS/ETS) region in the seawhip, Junceella fragilis,
and identified an 8-bp motif at the 5'- ETS/18S rDNA boundary closely
resembling a fungal pre-rRNA A1 cleavage signal. This apparent
conservation of processing signals was unexpected, as no corresponding
sequence has previously been reported in any animal. The J. fragilis
IGS sequence lacks repetitive motifs of the type typical of higher
animals, but a microsatellite is present in the putative 3'-ETS.
Comparisons of the IGS between geographically isolated populations of J. fragilis indicate an unexpected lack of sequence variation.
Key words: IGS, ETS, rRNA processing, Cnidaria, Lower animals.
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