Effect of heterospecific DNA on the development of Rana nigromaculata.

Both the DNA of a balancer-bearing species (Cynops orientalis) and that of a non-balancer-bearing species (Rana nigromaculata), when injected into the fertilized eggs of R. nigromaculata, cause some tadpoles derived from the injected eggs to bear a single balancer-like process on the left operculum. Based upon these results, it may be so concluded that the occurrence of the balancer-like process in the tadpole is neither due to genetic transformation, nor due to balancer induction, but rather due to a non-specific developmental effect of DNA.