Complete Sequence and Gene Organization of the Nosema heliothidis Ribosomal RNA Gene Region

Abstract

By sequencing the entire ribosomal RNA (rRNA) gene region of Nosema heliothidis isolated from cotton bollworm (Helicoverpa armigera), we showed that its gene organization is similar to the type species, Nosema bombycis: the 5'-large subunit rRNA (2,490 bp)-internal transcribed spacer (192 bp)-small subunit rRNA (1,232 bp)-intergenic spacer (274 bp)-5S rRNA (115 bp)-3'. We constructed two phylogenetic trees, analyzed phylogenetic relationships, examined rRNA organization of microsporidia, and compared the secondary structure of small subunit rRNA with closely related microsporidia. The latter two features may provide important information for the classification and phylogenetic analysis of microsporidia.

Nosema sp. PM-1, a new isolate of microsporidian from infected Papilio machaon Linnaeus, based on ultrastructure and molecular identification

“…4). This result was consistent with those of previous studies (Liu et al 2008;Dong et al 2011) in which group I is ˝trueN osema and group II contains both Vairimorpha and Nosema. Nosema sp.…”

“…3): LSU (1-2497), ITS (2498-2676), SSU (2677-3908), . This structure was the same as those ˝true˝Nosema species such as N. bombycis (Dong et al 2011).…”

“…Nosema sp. PM-1, one of the members of group I, had the same rRNA gene arrangement as the ˝true˝Nosema species (Dong et al 2011), strongly suggesting that PM-1 was ˝true˝Nosema. Four additional phylogenetic trees of LSU+ITS+SSU, RPB1, α-tubulin, and β-tubulin gene sequences were constructed respectively to further confirm the affinity of PM-1 among group I.…”

“…Moreover, Nosema is one of the largest genera that comprise microsporidia. Most Nosema species have susceptible insect hosts in two orders, Lepidoptera and Diptera, and most species that infect Lepidoptera belong to the Vairimorpha and Nosema genera (Dong et al 2011;Tsai et al 2003;Liu et al 2012).…”