Transfer, Incorporation, and Substitution of Envelope Fusion Proteins among Members of the Baculoviridae , Orthomyxoviridae , and Metaviridae (Insect Retrovirus) Families

Recent research suggests that members of the Baculoviridae family can be divided into two groups on the basis of their envelope fusion proteins (31). One group utilizes proteins related to GP64. Homologs of GP64 are also used by the thogotoviruses (27), a genus of the Orthomyxoviridae family. Members of the other group of baculoviruses utilize envelope fusion proteins related to a protein called LD130. LD130 has been shown to be related to the envelope protein of insect retroviruses in the genus Errantivirus (family Metaviridae) (24, 36). In this review, the evidence for these data is outlined and possible pathways of transfer, incorporation, and substitution are discussed.