Fig. 2. Pvr alleles generated by EMS mutagenesis. (A) Schematic of the Pvr proteins noting the location of lesions predicted to severely truncate the Pvr protein. In Pvr⁹⁷⁴², Q143 is converted to a stop codon. In Pvr⁵³⁶³, a 61-base deletion results in the deletion of amino acids 114-134 and a subsequent frameshift that results in three new amino acids and a stop codon. (B) Molecular lesions in Pvr alleles. Four alleles truncate the protein, four alleles contain missense mutations in the extracellular domain and three contain missense mutations in the kinase domain. (C) Western blots containing protein from the genotypes indicated probed with anti-Pvr antiserum. A single major protein species is detected in wild-type flies. This species cannot be detected in the Pvr mutants. Blots were reprobed with anti-Elav antiserum to confirm that similar or greater levels of protein were present in mutant lanes compared with wild-type controls.