1994 Fiscal Year Final Research Report Summary

Molecular evolutionary studies on the origin of eukaryotes-Analyzes of informational macromolecules.

Research Project

Project/Area Number	05640793
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	系統・分類
Research Institution	The Nihon University
Principal Investigator	INOUE Tadashi The Nihon Univ. Dept. Agric. Veter. Med. Associate Prof., 農獣医学部, 助教授 (90124213)
Project Period (FY)	1993 – 1994
Keywords	Nosema bombycis / Ribosomal RNA / Elongation factor
Research Abstract	In order to investigate the evolutionary origin of eukaryotes, the sequences of ribosomal RNA genes and elongation factors of some microsporidia including Nosema bombycis which is believed to diverge at early stage of eukaryotes are examined by conventional methods. The originisms used were two strains of N.bombycis, Vairimorpha sp. M12 and Pleistophora sp.. The target genes were PCR-amplified by using appropriate primers from the total genomic DNA which had been extracted from their spores. The complete sequences of the small subunit ribosomal RNA (SSU rRNA) genes were obtained from the above four samples. The lengths of the SSU rRNAs were shorter than those of ordinary prokaryotes, and the secondary structure models constructed from the sequence lacked several stems which are common for the eukaryotic SSU rRNAs. This fact may indicate that the microsporidian SSU rRNA stayd in the primitive evolutional stage. Attempt to sequence the elongation factors was failed because of the lack of information for the appropriate primers to amplify the gene.