Institution: | (1) Department of Molecular Biology, Section of Microbiology, University of Siena, Via Laterina 8, 53100 Siena, Italy e-mail: marri@unisi.it Tel.: +39 0577 263850 Fax: +39 0577 263870, IT;(2) Department of Animal Biology and Genetics, University of Florence, Via Romana 17, 50125 Florence, Italy, IT |