Subject: 5S RNA

From: [email-masked]
Date: 20 Jun 95 10:10:29 +1000

Adan Marchant wrote:
>Could someone please tell me in which taxonomic groups the 5S rDNA is part
>of the main (SSU, 5.8S, LSU) repeat unit, and in which groups it is located
>elsewhere in the genome?

We have been examining the organisation of 5S rRNA genes in protists (simple
eukaryotes).   Some protists have the 5S rRNA gene linked to the large subunit
rRNA gene of the RDNA repeat (eg. Pythium spp. with filamentous sporangia,
Phytophthora spp., Saprolegnia and crytomonad algae) but other protists (eg.
Pythium spp. with globose or unknown sporangia) have 5S rRNA genes unlinked to
the rDNA repeat (Belkhiri et al. 1992; Howlett et al. 1992).  We have discussed
this evolutionary trend in Gilson et al. (1995).

References:
Belkhiri A, Buchko J, Klassen GR (1992) The 5S ribosomal RNA gene in Pythium 
species: two different genomic locations. Mol Biol Evol  9:1089-1102
Howlett BJ, Brownlee AG, Guest DI, Adcock GJ, McFadden GI (1992)  The 5S
ribosomal RNA gene is linked to the large and small subunit ribosomal RNA genes
in the oomycetes, Phytophthora vignae, P. cinnamoni, P. megasperma f.sp.
glycinea  and Saplrolegnia ferax   Curr Genet 21:455-461
Gilson PR, Adcock G, Howlett BJ and McFadden GI (1995) Organisation and
sequence analysis of nuclear-encoded 5S ribosomal RNA genes in Cryptomonad
Algae. Curr Genet 27:239-242.

Barbara J Howlett
Plant Cell Biology Research Centre
School of Botany      	       	       	       	       	       	       	    
University of Melbourne, Parkville 3052 VIC
Australia
 phone: +61 3 9344 5062 or +61 3 9344 5053
 fax:   +61 3 9347 1071
 email   [email-masked]