Transmission of beneficial yeasts accompanies offspring production in Drosophila – an initial evolutionary stage of insect maternal care through manipulation of microbial load?

Parent-to-offspring transmission of beneficial microorganisms is intimately interwoven with the evolution of social behaviors. Ancestral stages of complex sociality-microbe vectoring interrelationships may be characterized by high costs of intensive parental care and hence only a weak link between the transmission of microbial symbionts and offspring production. We investigate the relationship between yeast symbiont transmission and egg-laying, as well as some general factors thought to drive the 'farming' of microscopic fungi by the fruit fly Drosophila melanogaster, an insect with no obvious parental care but which is highly dependent on dietary microbes during offspring development. The process of transmitting microbes involves flies ingesting microbes from their previous environment, storing and vectoring them, and finally depositing them in a new environment. This study revealed that fecal materials of adult flies play a significant role in this process, as they contain viable yeas..., Yeast Transmission by Individual Drosophila melanogaster Females:

750 µL of raspberry medium filled in plastic cups placed inside plastic vials.
Observations made on mature female flies' residence time, body size, and yeast load.
Patch residence time is calculated from entry and exit times.
Yeast cells were collected from individual flies' bodies and patches and were quantified using a selective yeast medium and counting colony-forming units (CFU).

Transmitted Yeast Fungi as Dietary Symbionts:

Axenic larvae prepared from freshly laid D. melanogaster eggs.
Larvae were individually placed in vials with sterile raspberry medium inoculated with specific yeast solutions.
Yeast isolates included Hanseniaspora uvarum, Pichia terricola, Wickerhamomyces pijperi, Candida californica, Starmerella bacilaris, and Saccharomyces cerevisiae.
Survival of larvae to adulthood was observed for each treatment.

The Crop as a Potential Storage Organ of Symbiotic Yeast Fungi:

Upon emergence, the flies wer..., 1. Yeast transmission by individual Drosophila melanogaster females

Investigated the relationship between yeast symbiont transmission and egg laying in Drosophila melanogaster.

Found that egg-laying females transmitted more yeast cells, suggesting a connection between symbiont transmission and offspring production.

Data Description:

Excel file with raw data including sample details, patch residence time, egg count, yeast counts from the patch and fly, and wing length as a proxy for fly size.

2. Transmitted yeast fungi as dietary symbionts

Tested whether yeast fungi transmitted by individual Drosophila melanogaster females serve as dietary symbionts.

Examined the survival of larvae in different treatments (control and various yeast species).

Data Description:

Data indicating the survival of larvae in different treatments, including control and specific yeast species.

3. The crop as a potential storage organ of symbiotic yeast fungi

Explored the potential of the crop...