The organisation of dinoflagellate chromosomes is exceptional among eukaryotes. Their genomes are the largest in the Eukarya domain, chromosomes lack histones and may exist in liquid crystalline state. Therefore, the study of the structural and functional properties of dinoflagellate chromosomes is of high interest. In this work, we have analysed the telomeres and telomerase in two Dinoflagellata species, Karenia papilionacea and Crypthecodinium cohnii. Active telomerase, synthesising exclusively Arabidopsis-type telomere sequences, was detected in cell extracts. The terminal position of TTTAGGG repeats was determined by in situ hybridisation and BAL31 digestion methods and provides evidence for the linear characteristic of dinoflagellate chromosomes. The length of telomeric tracts, 25-80 kb, is the largest among unicellular eukaryotic organisms to date. Both the presence of long arrays of perfect telomeric repeats at the ends of dinoflagellate chromosomes and the existence of active telomerase as the primary tool for their high-fidelity maintenance demonstrate the general importance of these structures throughout eukaryotes. We conclude that whilst chromosomes of dinoflagellates are unique in many aspects of their structure and composition, their telomere maintenance follows the most common scenario.

• MeSH
• chromatin genetika   metabolismus   MeSH
• chromozomy genetika   metabolismus   ultrastruktura   MeSH
• Dinoflagellata genetika   růst a vývoj   metabolismus   ultrastruktura   MeSH
• kapalné krystaly MeSH
• protozoální DNA genetika   MeSH
• repetitivní sekvence nukleových kyselin MeSH
• replikace DNA genetika   MeSH
• telomerasa metabolismus   MeSH
• telomery genetika   metabolismus   ultrastruktura   MeSH
• zlomy DNA MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chromatin MeSH
• protozoální DNA MeSH
• telomerasa MeSH