Work

Wolbachia infection and its effects on mitochondrial ND5 gene variation in Aedes albopictus from Shandong Province

Year: 2026

Type: article

Abstract: Introduction Wolbachia , a matrilineally inherited endosymbiont, has the potential to influence host mitochondrial DNA (mtDNA) diversity through cytoplasmic hitchhiking and selective sweeps. Aedes albopictus naturally harbors Wolbachia , making it an ideal model for studying host-symbiont interactions. However, Wolbachia infection in Shandong Province and its effects on host mitochondrial ND5 gene remain poorly characterized. Methods A total of 388 female Ae. albopictus were collected from 16 cities across 5 climatic zones in Shandong. Wolbachia infection was detected using wsp -based typing primers, and geographical distribution and climatic responses were analyzed. ND5 gene was amplified and sequenced. Haplotype networks, phylogenetic trees, and Wolbachia -ND5 association plots were constructed. Correlation analyses, neutrality tests, and AMOVA were performed to assess the associations between Wolbachia infection and ND5 genetic diversity. Results The overall Wolbachia infection rate was 92.8%, with coinfection A&B as the dominant type (81.4%), followed by “ w AlbB only” (6.2%) and “ w AlbA only” (5.2%) infections. The infection rate varied notably among cities (61.5–100%) and climatic regions (77.6–98.7%). The overall infection and coinfection rates were negatively correlated with temperature, while the “ w AlbA only” rate was positively correlated with precipitation. A total of 21 ND5 haplotypes, one w AlbA haplotype, and four w AlbB haplotypes were identified. Hap1 and Hap2, the ND5 haplotypes more closely associated to Wolbachia , were predominant and most broadly distributed among populations. Compared with the Wolbachia uninfected group, ND5 nucleotide diversity was reduced in the infected, “ w AlbB only,” and coinfection groups, while haplotype diversity was reduced in the “ w AlbA only” group. Neutrality tests showed significantly negative Tajima’s D and Fu’s Fs for the infected and coinfection groups, suggesting recent population expansion or selective sweeps. Discussion This study revealed a high Wolbachia prevalence in Shandong Ae. albopictus , with coinfection A&B dominant and notable regional heterogeneity. The low genetic diversity of both Wolbachia and ND5, combined with reduced diversity in infected groups and significant negative neutrality test values, supported Wolbachia -associated selective sweeps on host mtDNA, although findings for the “ w AlbA only” group should be interpreted cautiously due to low sample size. This study provided opportunities to better understand host-symbiont interactions, showing potential value for vector monitoring and control.

Source: Frontiers in Microbiology

DOI: 10.3389/fmicb.2026.1943745