Submitted to: International Organization for Mycoplasmology
Publication Type: Abstract Only
Publication Acceptance Date: March 2, 1998
Publication Date: N/A
Like the genome of some other members of the class Mollicutes, the phytoplasma genome contains two rRNA operons (1,3,4). While little is known about sequence variance between the two rRNA operons of a given phytoplasma, differences in nucleotide sequence between the two operons have been demonstrated in two phytoplasmas. RFLP patterns of PCR-amplified DNA indicated the presence of two different 16S rRNA gene sequences in clover phyllody phytoplasma (2), and study of the Phormium yellow leaf phytoplasma indicated that this organism has two different 16S rRNA gene sequences (3). Although it is not known just how widespread rRNA interoperon heterogeneity may be among phytoplasmas, it may not be an uncommon occurrence. In this paper we report that PCR amplification of sequences from both phytoplasmal rRNA operons may be influenced by the choice of oligonucleotide sequences used to prime the PCR. Our use of alternative PCR primers resulted in the differential amplification of sequences from one or both rRNA operons; RFLP and sequence analyses of cloned PCR products revealed interoperon heterogeneity among phytoplasmas belonging to groups 16SrI, 16SrIII, and 16SrVI.