This possibility is consistent with our observation that Upk3lΔCT is unable to rescue the upk3l morphant phenotype, as well as reports that interactions between xUP3a and Src are critical for fertilized egg activation [10], [11], the discovery that bacterial-induced phosphorylation of hUP3a Thr244 by casein kinase II promotes umbrella cell apoptosis [12], and data showing that some patients with renal adysplasia have defects in the conserved GRR motif or a critical proline residue (P273) in the CT of hUP3a [8]. This evidence concerns the gene SRC and Bilateral renal dysplasia.