MATERNAL RNAs stored in eggs play an essential role during the initial stage of embryonic de-velopment in animals and they are degraded as the development proceeds. In some animals (e.g. fish and amphibian), zygotic genes begin to transcribe new mRNA only when the embryosdevelop to about midblastula stage. This degradation of maternal RNA and synthesis of zygotic MATERNAL RNAs stored in eggs play an essential role during the initial stage of embryonic de-development in animals and they are degraded as the development proceeds. In some animals (eg fish and amphibian), zygotic genes begin to transcribe new mRNA only when the embryos development This degradation of maternal RNA and synthesis of zygotic