The participation of the embryonic genome during early cleavage in the rabbit

Actinomycin D and the mushroom toxin α-amanitin similarly inhibit ribonucleic acid synthesis in the rabbit zygote. Actinomycin D also causes an immediate arrest of cleavage, whereas α-amanitin allows limited further development. The decreasing rate of amino acid incorporation caused by continuous exposure of cleaving rabbit embryos to α-amanitin suggests that a relatively homogeneous embryonic RNA is involved in the support of early protein synthesis and is turning over with a half-life of approximately 24 hr, or three cell generation times.