1996 Volume 61 Issue 1 Pages 63-67
DNA-fluorescence from nuclei and nucleoids in gametes of Ulva pertusa have beenmeasured after staining with 4'-6-diamidino-2-phenylindol. The nuclei emitted 2.2 times as much fluorescence as that from haploid Chlamydomonas reinhardtii, whose nuclei have been reported to contain 7.2 × 1010 daltones (Chiang and Sueoka 1967) and a GC content of 62.1% (Sager and Ishida 1963). The average nucleoid number of U. pertusa from 100 gametes observed was 7.97±2.60 (S.D.). DNA fluorescence of each nucleoid ranged from 0.27 to 8.0 times as much as that of T4 phage, which has been reported to contain 1.1 × 108 daltons of DNA (Freifelder 1970), with a GC content of 36% (Runder et al. 1969). Total nucleoid DNA-fluorescence in a cell of U. pertusa was 22.4 to 32.3 times as much as tht of T4 phage.
