 The ZFN-encoding mRNA was injected into one-cell embryos and a high percentage of animals carried the desired mutations and phenotypes.Their research work demonstrated that ZFNs can specifically and efficiently create heritable mutant alleles at loci of interest in the germ line, and ZFN-induced alleles can be propagated in subsequent generations.Similar research of using ZFNs to create specific mutations in zebrafish embryo has also been carried out by other research groups.