1. Department of Molecular Biology, University of Gdańsk, Kladki 24, 80-822 Gdańsk, Poland1
2. Laboratory of Molecular Biology (affiliated with the University of Gdańsk), Polish Academy of Sciences, Kładki 24, 80-822 Gdańsk, Poland2
3. Max-Planck-Institut für Molekulare Genetik, Ihnestrasse 73, D-14195 Berlin-Dahlem, Germany3
4. Marine Biology Centre, Polish Academy of Sciences, Św. Wojciecha 5, 81-347 Gdynia, Poland4