Genome and cell sizes in frogs: A comparison with salamanders

Summary The nuclear volume (Nv), cell volume (Cv) and cell surface area (Cs) of erythrocytes from 26 anuran species show a linear and direct correlation with the nuclear DNA content; the Cs/Cv ratio tends to decrease as DNA increases. Analogous phenomena are found in urodeles possessing less than 70 pg/N of DNA, whereas in those with a larger genome there is a trend towards stabilization of the Cs/Cv ratio. The same mechanisms appear to control the ratios of genome sizes to cell sizes within the amphibians and possibly in other vertebrates as well. The former, however, seem to avail themselves to a greater extent of the adaptive properties inherent in their genome and cell size variations.Research supported by a grant from the Italian CNR.