STUDIES ON THE RIBOSOMAL RNA GENE(rDNA)OF A MICROSPORIDIUM ISOLATED FROM PIERIS RAPAE L
菜粉蝶微孢子虫核糖体RNA(rRNA)编码基因的研究

Nuclotide sequence (1205 bp) of small subunit ribosomal RNA (SSUrDNA) of a microsporidium isolated from Pieris rapae L. (abbr:MPr) was specifically amplified by polymerase chain reaction (PCR). Another fragment of 657 bp downstream of MPr SSUrDNA 3'end was amplified with two other primers. Within this 657 bp fragment, the putative 3'terminus of MPr SSUrDNA and the extreme 5' of large subunit ribosomal RNA gene. (LSUrDNA) were identified, which situated at base 145, 146-186 and 187, respectively. Then the full sequence of MPr ssurDNA is 1245 bp. Its GC content was also nearly 34%. The ITS region (internal transcribed spacer), positioned between the ssu and LSUrRNA genes, was found to be 41 bp in length. The LSUrDNA 580r region of MPr is 470 bp, longer than 437 bp of Nosema apis, 447 bp of Nosema algerae. The secondary structure of MPr SSUrRNA was constructed. These analyses of MPr rRNA gene contributed to the somewhat limited microsporidian taxonomic classification based on morphology.