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Updated: Jul 1, 2026
Generation of Monoclonal Cultures from Wolbachia-infected Drosophila melanogaster JW18 Cell Line
Published on: June 27, 2025
Nonrandom Wolbachia infection status of Drosophila melanogaster strains with different mtDNA haplotypes
Maria D S Nunes1, Viola Nolte, Christian Schlötterer
1Institut für Populationsgenetik, Veterinärmedizinische Universität Wien, Veterinärplatz 1, Vienna, Austria.
Abstract:
Wolbachia are maternally inherited bacteria, which typically spread in the host population by inducing cytoplasmic incompatibility (CI). In Drosophila melanogaster, Wolbachia is quite common but CI is variable, with most of the studies reporting low levels of CI. Surveying mitochondrial DNA (mtDNA) variation and infection status in a worldwide D. melanogaster collection, we found that the Wolbachia infection was not randomly distributed among flies with different mtDNA haplotypes. This preferential infection of some mtDNA haplotypes could be caused by a recent spread of mtDNA haplotypes associated with the infection. The comparison of contemporary D. melanogaster samples with lines collected more than 50 years ago shows that indeed one haplotype with a high incidence of Wolbachia infection has increased in frequency. Consistent with this observation, we found that the acquisition of a Wolbachia infection in a population from Crete was accompanied with an almost complete mtDNA replacement, with the Wolbachia-associated haplotype becoming abundant. Although it is difficult to identify the evolutionary forces causing the global increase of wMel, the parallel sweep of Wolbachia and an mtDNA haplotype suggests a fitness advantage of the Wolbachia infection.
Insights
Wolbachia bacteria are spreading rapidly in Drosophila melanogaster fly populations, coinciding with a rise in specific mitochondrial DNA (mtDNA) haplotypes. This suggests the Wolbachia infection provides a fitness advantage to the flies.
Area of Science:
- Evolutionary biology
- Microbiology
- Genetics
Background:
- Wolbachia are maternally inherited bacteria known to spread via cytoplasmic incompatibility (CI).
- In Drosophila melanogaster, Wolbachia infections are common, but CI levels are often low and variable.
- The distribution of Wolbachia infection across different mitochondrial DNA (mtDNA) haplotypes in D. melanogaster is not well understood.
Purpose of the Study:
- To investigate the relationship between Wolbachia infection and mtDNA variation in Drosophila melanogaster.
- To determine if specific mtDNA haplotypes are preferentially infected by Wolbachia.
- To examine the historical and contemporary frequency changes of Wolbachia-associated mtDNA haplotypes.
Main Methods:
- Surveying mtDNA variation and Wolbachia infection status in a global collection of D. melanogaster.
- Comparing contemporary D. melanogaster samples with historical lines (over 50 years old).
- Analyzing mtDNA replacement in a specific Wolbachia-infected population from Crete.
Main Results:
- Wolbachia infection was non-randomly distributed among different mtDNA haplotypes.
- A specific mtDNA haplotype associated with high Wolbachia infection incidence has increased in frequency over time.
- A Wolbachia infection in a Crete population was linked to a near-complete replacement by a specific mtDNA haplotype.
Conclusions:
- The parallel increase of Wolbachia infection and specific mtDNA haplotypes suggests a fitness advantage conferred by the infection.
- Wolbachia may drive significant changes in host mtDNA haplotype frequencies.
- Further research is needed to fully elucidate the evolutionary forces behind the global increase of the wMel strain of Wolbachia.
