CHARACTERIZATION OF CELL-CULTURES DERIVED FROM FUGU, THE JAPANESE PUFFERFISH

The Japanese pufferfish (genus Fugu), which possesses a highly compact genome, is becoming a popular model among those interested in sequenc ing and mapping the genomes of higher vertebrates. Although genomic li braries have been derived and used to study the molecular biology of F ugu, biological material derived from the living organism is difficult to obtain for laboratories distant from the Asian Pacific. We have es tablished cell cultures from two Fugu species: kusafugu, Fugu niphoble s, and torafugu, F. rubripes. Cultures derived from F. niphobles fry a nd F. rubripes eye have been passaged more than 60 times over the cour se of one year, representing approximately 180 population doublings. P roliferating cultures were also initiated from F. rubripes brain, live r, fin, spleen, kidney, swimbladder, and muscle. Karyotype analyses in dicated that F. rubripes eye-derived cells possessed a chromosome numb er in the diploid range; F. niphobles fry cells were slightly hyperplo id. Flow cytometry confirmed that the relative amounts of DNA present in cultured cells from both Fugu species were similar to that measured in blood cells collected from F. rubripes, and approximately one-seve nth of that measured in diploid human cells. Telomerase activity was e asily detectable in lysates prepared from F. niphobles fry cells and F . rubripes eye cells, consistent with the notion that these cultures a re capable of indefinite proliferation.