The d polymorphism has been introduced into ref(2)P+++.O1.cCMa. This polymorphism consists of amino acid residues Q28 and N29 (in the PB1 domain) being replaced by a single G residue.
ref(2)Pd++.O1.cCMa is "unfunctional" (neither restrictive nor permissive) for sigma virus multiplication.
ref(2)Pod3/Df(2L)E55 males carrying ref(2)Pd++.O1.cCMa are fertile.