Fig. 3: Synteny of nudiviral genes loci and proviral loci (PL) between C. congregata and M. demolitor.

A C. congregata chromosome map with the position of 24 nudiviral genes loci. B Comparisons between nudiviral gene regions of C. congregata and M. demolitor. Synteny between the two species has been characterized by at least two hymenopteran (non-viral) orthologous genes in the vicinity of homologous nudiviral gene(s) of both species. Genome scaffolds are represented in black. Red boxes indicate nudiviral genes and white boxes refer to hymenopteran genes. 1. the vp91 region is orthologous indicating the position of this gene was inherited from their common ancestor 53 mya; 2. the fen region is also orthologous but an expansion occurred specifically in Cotesia lineage giving rise to six copies; 3. the organization of the nudiviral cluster encoding in particular capsid genes has remained strikingly similar with the same viral genes in the same order (except p6-9-2) in both species indicating strong evolutionary constraints. C C. congregata chromosome map with the position of gene loci corresponding to the highly expanded odv-e66 nudiviral gene family. D Comparison of two odv-e66 loci showing that expansion occurred before (cluster 7) and after (cluster 4) the separation of both species E C. congregata chromosome map with the position of Proviral Loci (PL) encoding virulence genes packaged in bracovirus particles. Note the concentration of loci (successively PL10-PL1-PL2 and PL4) in a 2 Mb region termed “macrolocus” and representing half of the chromosome 5 short arm. F Comparison of C. congregata and M. demolitor PL. Numbers 1 to 37 and letters correspond to the different dsDNA circles present in CcBV and MdBV particles produced from the PL. Blue boxes indicate virulence genes while white boxes refer to hymenopteran genes and the red boxes to a nudiviral odv-e66 gene located between PL1 and PL2 and 58b near PL3-PL7. Ø indicates the absence of orthologs PL in the M. demolitor genome.