Now I got two mutant lines of a gene in zebrafish. One line has nonsense RNA decay, which is knocked out in the middle exon(5th exons) of the whole gene(9 exons in total). And another line does not have RNA decay, which is knocked out in the 7th exon/9 exons. Can the mutant line without the nonsense RNA decay be viewed as a successful knockout? and why? Thanks!!