The orphan genes of bacteriophage T4, a biological dark matter
Bacteriophage T4, a prototype of lytic bacterial viruses, is one of the organisms that help founding molecular biology. In 1963, 63 genes that are essential for the viral lytic cycle under standard laboratory conditions were identified genetically. We now know that the viral genome encodes about 300 genes. 120 of the genes have no known function and the proteins they encode show almost no homology to those sequenced cellular organisms. We are attempting to define the function of these ORFans by expressing them conditionally in uninfected bacteria and by characterizing characterizing the pathological effects of their expression. We are also inactivating these genes in the T4 genome to determine whether their presence confers a long term evolutionary advantage.