1. Department of PhysiologyCharing Cross and Westminster Medical SchoolUniversity of LondonLondonW6 8RFU.K.
2. Department of Cellular and Molecular SciencesSt. George's Medical SchoolUniversity of LondonLondonSW17 OREU.K.
3. Joint Institute for Nuclear ResearchDubnaMoscow Region141980Russia
4. Clarendon LaboratoryUniversity of OxfordParks RoadOxfordOX1 3PUU.K.
5. Institute of CytologyRussian Academy of Sciences194064St. PetersburgRussia