2009 Fiscal Year Final Research Report

The effect of genetic structure of Semisulcospira spp. endemic to Lake Biwa on the susceptibility to a digenean Genarchopsis spp.

Research Project

Project/Area Number	19570023
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Ecology/Environment
Research Institution	The University of Shiga Prefecture
Principal Investigator	URABE Misako The University of Shiga Prefecture, 環境科学部, 准教授 (50263421)
Project Period (FY)	2007 – 2009
Keywords	進化生態 / 寄生 / 系統 / 遺伝的多様性
Research Abstract	An parasitic digenean Genarchopsis goppo, which parasitizes almost all species of the freshwater snails (genus Semisulcospira) in Lake Biwa, shows some variations in host specificity among localities. As the result of experimental infections and molecular phylogenetic analysis, at least two cryptic species were discovered in Lake Biwa and one of the tributaries. The susceptibility of a host species did not vary among local populations. This result suggests that the host-parasite association between G.goppo and Semisulcospira is the consequence of their speciation. The molecular genetic study suggested the presence of genetic penetration among host species. Therefore, their genetic diversity cannot be compared simply by the haplotypes. The genetic divergence through interbreeding and its effect on the susceptibility are the goal of the further studies.