Open AccessParamecium caudatum acquires heat‐shock resistance in ciliary movement by infection with the endonuclear symbiotic bacterium Holospora obtusa
Author(s) -
Fujishima Masahiro,
Kawai Miki,
Yamamoto Ryu
Publication year - 2005
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/j.femsle.2004.11.053
Subject(s) - paramecium caudatum , macronucleus , biology , ciliate , microbiology and biotechnology , bacteria , paramecium , botany , genetics
Holospora obtusa is a macronucleus‐specific bacterium of the ciliate Paramecium caudatum . Three types of P. caudatum cells ( H. obtusa ‐free cells, cells bearing the reproductive form of H. obtusa and cells bearing the predominantly infectious form of H. obtusa ) cultured at 25 °C were transferred to 4, 10, 25, 35 and 40 °C and their swimming velocities were measured by taking photomicrographs with two‐second exposures. The H. obtusa ‐free cells almost ceased swimming at both 4 and 40 °C, while cells bearing the reproductive form and those bearing the predominantly infectious form actively swam even at these temperatures. These results show that the host cell can acquire heat‐shock resistance when infected by H. obtusa in the macronucleus. This is the first evidence to show that the endonuclear symbiont Holospora contributes to maintain the ciliary movement of the host even at temperatures unsuitable for the host growth.