Perlecan knockdown in embryonic zebrafish has been achieved through the use of Morpholinos targeted to the perlecan transcript. Morpholinos were used to block translation of the perlecan mRNA in zebrafish embryos, as part of an investigation into perlecan function in skeletal and vascular development. The Morpholino targets the five prime untranslated region of the perlecan mRNA thus blocking translation of the message. Loss of the perlecan protein in these fish led to serious myopathies and circulation problems. As shown in a later study from the same laboratory, this phenotype could be rescued through the addition of exogenous VEGF-A.