Preliminary genome assembly of the Wolbachia endosymbiont of the South American fruit fly Anastrepha fraterculus sp. 1.

Wolbachia sp., an alphaproteobacterium associated with reproductive phenotypes, has previously been characterized in the fruit fly pest Anastrepha fraterculus (Diptera: Tephritidae). Two Wolbachia strains (wAfraCast1_A and wAfraCast2_A) have been identified using MLST and HVR as molecular markers. Mating assays have revealed a female-biased sex ratio in flies carrying wAfraCast1_A, while behavioral tests have suggested a protective effect against parasitoids in A. fraterculus larvae harboring wAfraCast2_A. Here, we assembled the wAfraCast2_A genome from a whole-genome project of A. fraterculus morphotype 1 (Argentina).

High-molecular-weight DNA was extracted from a single adult female, and Oxford Nanopore high-throughput genome sequencing was performed. After quality control and filtering of raw reads, a metagenomic approach was followed to obtain de novo assemblies of A. fraterculus and Wolbachia sp. genomes, and a Wolbachia-assigned contig was further analyzed. Quast and BUSCO were used to check the integrity and completeness of a preliminary Wolbachia genome assembly. Annotation was carried out with Prokka and compared to the reference genome of the Wolbachia endosymbiont of Drosophila melanogaster (wMel).

A total of 15,810,325 reads were obtained after adapter removal and quality filtering (10% of the reads were discarded). From these, a total of 1,360 contigs were generated de novo, and 1 contig was assigned to the Wolbachia sp. taxon. A preliminary assembly of the wAfraCast2_A genome revealed a circularized contig of 1,463,312 bp with 93.1% completeness, 0% duplicated genes, and 6.9% missing genes (rickettsiales_odb10 database, n:364). A genome comparison with wMel showed an Average Nucleotide Identity of 99.1% and structural annotation identified 1,701 CDSs, including 633 genes, 907 hypothetical proteins, 3 rRNAs, and 34 tRNAs. These results will enhance our understanding of the Wolbachia–A. fraterculus interaction, including mechanisms influencing host behavior, physiology, and ecological functions, thereby supporting novel pest management strategies.