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Nesidiocoris tenuis(Reuter) is an efficient predatory biological control agent used throughout the Mediterranean Basin in tomato crops but regarded as a pest in northern European countries. From the family Miridae, it is an economically important insect yet very little is known in terms of genetic information and no genomic or transcriptomic studies have been published. Here, we use a linked‐read sequencing strategy on a single femaleN. tenuis. From this, we assembled the 355 Mbp genome and delivered anab initio, homology‐based and evidence‐based annotation. Along the way, the bacterial “contamination” was removed from the assembly. In addition, bacterial lateral gene transfer (LGT) candidates were detected in theN. tenuisgenome. The complete gene set is composed of 24 688 genes; the associated proteins were compared to other hemipterans (Cimex lectularis,Halyomorpha halysandAcyrthosiphon pisum). We visualized the genome using various cytogenetic techniques, such as karyotyping, CGH and GISH, indicating a karyotype of 2n= 32. Additional analyses include the localization of 18S rDNA and unique satellite probes as well as pooled sequencing to assess nucleotide diversity and neutrality of the commercial population. This is one of the first mirid genomes to be released and the first of a mirid biological control agent.

 

Abstract Males in the parasitoid wasp genus Nasonia have distinct, species-specific, head shapes. The availability of fertile hybrids among the species, along with obligate haploidy of males, facilitates analysis of complex gene interactions in development and evolution. Previous analyses showed that both the divergence in head shape between Nasonia vitripennis and Nasonia giraulti, and the head-specific developmental defects of F2 haploid hybrid males, are governed by multiple changes in networks of interacting genes. Here, we extend our understanding of the gene interactions that affect morphogenesis in male heads. Use of artificial diploid male hybrids shows that alleles mediating developmental defects are recessive, while there are diverse dominance relationships among other head shape traits. At the molecular level, the sex determination locus doublesex plays a major role in male head shape differences, but it is not the only important factor. Introgression of a giraulti region on chromsome 2 reveals a recessive locus that causes completely penetrant head clefting in both males and females in a vitripennis background. Finally, a third species (N. longicornis) was used to investigate the timing of genetic changes related to head morphology, revealing that most changes causing defects arose after the divergence of N. vitripennis from the other species, but prior to the divergence of N. giraulti and N. longicornis from each other. Our results demonstrate that developmental gene networks can be dissected using interspecies crosses in Nasonia, and set the stage for future fine-scale genetic dissection of both head shape and hybrid developmental defects. 

Wolbachia are widespread intracellular bacteria that mediate many important biological processes in arthropod species. In this study, we identified 210 conserved single-copy genes in 33 genome-sequenced Wolbachia strains in the A, B, C, D, E and F supergroups. Phylogenomic analyses with these core genes indicate that all 33 Wolbachia strains maintain the supergroup relationship, which was classified previously based on the multilocus sequence typing (MLST) genes. Using an interclade recombination screening method, 14 inter-supergroup recombination events were discovered in six genes (2.9%) among 210 single copy orthologs. This finding suggests a relatively low frequency of intergroup recombination. Interestingly, they have occurred not only between A and B supergroups (9 events), but also between A and E supergroups (5 events). Maintenance of such transfers suggests possible roles in Wolbachia infection related functions. Comparisons of strain divergence using the five genes of the MLST system show a high correlation (Pearson correlation coefficient r = 0.98) between MLST and whole genome divergences, indicating that MLST is a reliable method for identifying related strains when whole genome data are not available. The phylogenomic analysis and the identified core gene set in our study will serve as a valuable foundation for strain identification and the investigation of recombination and genome evolution in Wolbachia.