# Non-ovarian Wolbachia pipientis titer correlates with fertility rescue of a Drosophila melanogaster bag of marbles hypomorph

## TL;DR

A study finds that the fertility rescue in fruit flies with a partial mutation is linked to the overall level of a bacteria called Wolbachia in the flies, not just in their ovaries.

## Contribution

The study reveals that Wolbachia titer in non-ovarian tissues, not ovarian titer, correlates with fertility rescue in a Drosophila melanogaster germline stem cell mutant.

## Key findings

- Ovarian Wolbachia titer does not differ between variants with low and high fertility rescue.
- Carcass Wolbachia titer differs between variants during peak fertility rescue.
- Combined ovarian and carcass Wolbachia titer positively correlates with fertility rescue.

## Abstract

Bag of marbles
(

bam

) is an essential gene that regulates germline stem cell maintenance and germline stem cell daughter cell differentiation in

Drosophila melanogaster

. When

bam

is partially functional (hypomorphic), the introduction of

Wolbachia pipientis

rescues the mutant fertility phenotype that would otherwise result in partial sterility. Infection by different

W. pipientis

variants results in differential rescue of the

bam

hypomorph fertility phenotype. We were intrigued by the varying degrees of rescue exhibited in the

bam

hypomorph when exposed to different

W. pipientis

variants, prompting us to investigate whether this phenomenon is attributable to variations in the titers of

W. pipientis

variants. We found no significant difference in ovarian titer between two

W. pipientis

variant groups,
w
Mel-like (low

bam

hypomorph fertility rescue) and
w
MelCS-like variants (higher

bam

hypomorph fertility rescue), at
bam
hypomorph peak fertility. However, carcass (whole flies without the ovaries) titer between
w
Mel-like and
w
MelCS-like infected
bam
hypomorph differed during peak fertility rescue. A positive correlation emerged between the combined titers of ovarian and carcass infections and fertility, implying a more extensive influence that extends beyond ovarian infection alone.