ABSTRACT
The intricate evolutionary dynamics of endosymbiotic relationships result in unique characteristics among the genomes of symbionts, which profoundly influence host insect phenotypes. Here, we investigated an endosymbiotic system in Phenacoccus solenopsis, a notorious pest of the subfamily Phenacoccinae. The endosymbiont, "Candidatus Tremblaya phenacola" (T. phenacola PSOL), persisted throughout the complete life cycle of female hosts and was more active during oviposition, whereas there was a significant decline in abundance after pupation in males. Genome sequencing yielded an endosymbiont genome of 221.1 kb in size, comprising seven contigs and originating from a chimeric arrangement between betaproteobacteria and gammaproteobacteria. A comprehensive analysis of amino acid metabolic pathways demonstrated complementarity between the host and endosymbiont metabolism. Elimination of T. phenacola PSOL through antibiotic treatment significantly decreased P. solenopsis fecundity. Weighted gene coexpression network analysis demonstrated a correlation between genes associated with essential amino acid synthesis and those associated with host meiosis and oocyte maturation. Moreover, altering endosymbiont abundance activated the host mechanistic target of rapamycin pathway, suggesting that changes in the amino acid abundance affected the host reproductive capabilities via this signal pathway. Taken together, these findings demonstrate a mechanism by which the endosymbiont T. phenacola PSOL contributed to high fecundity in P. solenopsis and provide new insights into nutritional compensation and coevolution of the endosymbiotic system.
Subject(s)
Betaproteobacteria , Gammaproteobacteria , Hemiptera , Animals , Male , Female , Sirolimus/metabolism , Betaproteobacteria/genetics , Gammaproteobacteria/genetics , Hemiptera/microbiology , Reproduction , Amino Acids/metabolism , SymbiosisABSTRACT
Hymenoptera is an order accounting for a large proportion of species in Insecta, among which Chalcidoidea contains many parasitoid species of biocontrol significance. Currently, some species genomes in Chalcidoidea have been assembled, but the chromosome-level genomes of Aphelinidae are not yet available. Using Illumina, PacBio HiFi and Hi-C technologies, we assembled a genome assembly of Eretmocerus hayati (Aphelinidae, Hymenoptera), a worldwide biocontrol agent of whiteflies, at the chromosome level. The assembled genome size is 692.1 Mb with a contig N50 of 7.96 Mb. After Hi-C scaffolding, the contigs was assembled onto four chromosomes with a mapping rate of > 98%. The scaffold N50 length is 192.5 Mb, and Benchmarking Universal Single-Copy Orthologues (BUSCO) value is 95.9%. The genome contains 370.8 Mb repeat sequences and total of 24471 protein coding genes. P450 gene families were identified and analyzed. In conclusion, our chromosome-level genome assembly provides valuable support for future research on the evolution of parasitoid wasps and the interaction between hosts and parasitoid wasps.
Subject(s)
Genome , Wasps , Animals , Benchmarking , Wasps/geneticsABSTRACT
The Colorado potato beetle (Leptinotarsa decemlineata) is one of the most notorious insect pests of potatoes globally. Here, we generated a high-quality chromosome-level genome assembly of L. decemlineata using a combination of the PacBio HiFi sequencing and Hi-C scaffolding technologies. The genome assembly (-1,008 Mb) is anchored to 18 chromosomes (17 + XO), with a scaffold N50 of 58.32 Mb. It contains 676 Mb repeat sequences and 29,606 protein-coding genes. The chromosome-level genome assembly of L. decemlineata provides in-depth knowledge and will be a helpful resource for the beetle and invasive biology research communities.
