Ancient origin of Jingchuvirales derived glycoproteins integrated in arthropod genomes

Abstract

Endogenous virus elements (EVEs) are viral-derived sequences integrated into their host genomes. EVEs of the Jingchuvirales order were detected in a wide range of insect genomes covering several distantly related families and Jingchuvirales-derived glycoproteins were recently associated by our group with the origin of a putative new retrovirus based on a glycoprotein captured by a mosquito retrotransposon. But, except for mosquitoes, there is a lack of a more detailed understanding of the endogenization mechanism, timing and frequency per viral lineages. Here we screened Jingchuvirales glycoprotein-derived EVEs (Jg-EVEs) in eukaryotic genomes. We found six distinct endogenization events of Jg-EVEs, that belong to two out of five known Jingchuvirales families (Chuviridae and Natareviridae). For seven arthropod families bearing Jg-EVEs there is no register of bona fide circulating chuvirus infection. Hence, our results show that Jingchuvirales viruses infected or still infect these host families, expanding their known host range. We estimated that two endogenization events occurred in the ancestors of the Myrmicinae-Ponerinae subfamilies (Pteromalidae - Hymenoptera order) around 155[~]54.8 MyA and Bombus genus (Hemiptera order) around (36[~]2 MyA). Although we found abundant evidence of LTR-Gypsy retrotransposons fragments associated with the glycoprotein in Hymenoptera and other insect orders, there is no evidence of potential functional glycoprotein capture. Our results show that the widespread distribution of Jingchuvirales glycoproteins in extant Arhtropods is a result of multiple ancient endogenization events and that these viruses fossils are being vertically inherited for millions of years through the Arthropods evolutionary tree. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=142 HEIGHT=200 SRC="FIGDIR/small/497255v1_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@194f47org.highwire.dtl.DTLVardef@1a3dd24org.highwire.dtl.DTLVardef@10b77bdorg.highwire.dtl.DTLVardef@1e21ffb_HPS_FORMAT_FIGEXP M_FIG C_FIG