, were separately purified and counted using a qNano particle analyzer. These EVs, showing different buoyant densities, were identically spherical in shape, and their sizes varied from 80 to 210 nm in diameter, with 120-and 190-nm sizes predominant. The average size of DNA packaged into EVs was about 14 kb. The DNA of the EVs in band C was sequenced and assembled. Mapping of the T. onnurineus NA1 T EV (ToEV) DNA sequences onto the reference genome of the parent archaeon revealed that most genes of T. onnurineus NA1 T were packaged into EVs, except for an ϳ9.4-kb region from TON_0536 to TON_0544. The absence of this specific region of the genome in the EVs was confirmed from band B of the same culture and from bands B and C purified from a different batch culture. The presence of the 3=-terminal sequence and the absence of the 5=-terminal sequence of TON_0536 were repeatedly confirmed. On the basis of these results, we hypothesize that the unpackaged part of the T. onnurineus NA1 T genome might be related to the process that delivers DNA into ToEVs and/or the mechanism generating the ToEVs themselves.