Title : Genomic insights on the endosymbiotic role of Candidatus Uzinura diaspidicola to coconut scale insects
Abstract:
Insects are known to harbor bacterial endosymbionts which play a vital role in insect survival, nutrition and reproduction. Aspidiotus destructor and A. rigidus, more commonly known as coconut scale insect, have caused massive infestation and economic damages for the Philippines. Using available resources and bioinformatic softwares, the genome assembly for the major endosymbiont, Candidatus Uzinura diaspidicola, were constructed and analyzed. The genome of U. diaspidicola strain A. rigidus is 174 Kb containing 290 genes, whereas the genome U. diaspidicola str. A. destructor is 273Kb containing 370 genes. Despite its reduced genome sizes, it has evidently retained genes involved in the biosynthesis of essential amino acids. This entails nutritional provision of U. diaspidicola to the Aspidiotus sp., contributing to increased fitness and adaptability. Its role in sex-determination and reproduction is yet to be confirmed. Comparative analysis of Uzinura diaspidicola of host species A. destructor and A. rigidus resulted to 92% average nucleotide index (ANI) and 47.3% genome to genome hybridization (GGH) values which supports their distinct identity and proves strong host-endosymbiont coevolution. Phylogenomic analysis further supports their genetic affinity with Flavobacteriales (i.e., Karelsulcia muelleri, Merdimorpha stercoravium, Shikimatogenerans sp., Walczuchella monophlebidarum). With this strong host-endosymbiont linkage, these bacterial endosymbionts can also be exploited as alternative IPM targets to control coconut scale insect populations.
