RESUMO
Microsporidia are ubiquitous intracellular parasitic protozoa infecting all types of animals. Their ribosomes and rRNAs are of prokaryotic size.In order to better understand their phylogenetic relationship and identify the uncertain species, the sequences of the small subunit ribosomal RNA (ssurRNA, 16 S rRNA) genes of nine microsporidia infectious to the silkworm, Bombyx mori, were determined. The results of phylogenetic trees and Southern blotting suggest all the nine strains of microsporidia are various species of the genus Nosema.
RESUMO
PHO85 is a versatile gene in Saccharomyces cerevisiae, which is involved in metabolism of inorganic phosphate and usage of carbon source, accumulation of glycogen, regulation of protein stability and cell cycle control. The viability of wild type budding yeast strain YPH499 and its derivative pho85Delta mutant, pho80 mutant, and pap1(pcl-7)Delta mutant in different cations were investigated and their tolerance to the cations(LC(50)) was measured. The results showed that the deletion of PHO85 or PHO80 gene both increased sensibility of Sacchromyces cerevisiae to ions K(+), Mg(2+), Zn(2+), Ca(2+) and Mn(2+), while the deletion of pap1(pcl-7) gene did not lead to such phenotype. The difference between the patterns of relative growth curve of the mutants and wild type strain in the above ions also implied that PHO80 was the unique PCLs in complex with PHO85 CDK, that were contributed to K(+) and Mg(2+) ion homeostasis control and there were some other PCLs besides PHO80 that were involved in Zn(2+), Ca(2+) and Mn(2+) tolerance regulation as cyclin of PHO85 CDK. Furthermore, the amount of the total cellular calcium of pho85Delta mutant, pho80Delta mutant and YPH499 indicated that the ability of calcium accumulation of pho85 mutant and pho80Delta mutant was impaired.