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A FACS-based Protocol to Isolate RNA from the Secondary Cells of Drosophila Male Accessory Glands
Published on: September 5, 2019
Drosophila males transfer antibacterial proteins from their accessory gland and ejaculatory duct to their mates
1Department of Molecular Biology and Genetics, Cornell University, 14853, Ithaca, NY, USA
Abstract:
The male fruitfly, Drosophila melanogaster, transfers to his mate proteins that increase his reproductive success by causing changes in her behavior and physiology. Here we show that among the transferred proteins are ones with antibacterial activity. We performed Escherichia coli overlay assays of native PAGE or renatured SDS-PAGE of reproductive tissue extracts of wild-type or transgenic males deficient in accessory gland function. We detected a 28 kDa male accessory gland-derived protein and two ejaculatory duct-derived proteins all with antibacterial activity. Based on its gel mobility and tissue of synthesis, one of the ejaculatory duct proteins is likely to be andropin, a previously-reported 6 kDa antibacterial peptide. All three proteins are transferred to females during mating. Therefore, they could assist in protecting the male's reproductive tract and, after transfer to the female, the female's reproductive tract or eggs against bacterial infection. Since seminal fluid proteins are transferred before the sperm, these antibacterial proteins may also protect sperm from bacterial infection.
Insights
Male fruit flies transfer antibacterial proteins to females during mating. These proteins protect both the male and female reproductive tracts and eggs from bacterial infections.
Area of Science:
- Reproductive biology
- Insect immunity
- Microbiology
Background:
- Male fruit flies (Drosophila melanogaster) transfer seminal fluid proteins to females during mating.
- These proteins influence female physiology and behavior, enhancing male reproductive success.
- The role of seminal fluid proteins in protecting against bacterial infection is not fully understood.
Purpose of the Study:
- To investigate the presence and function of antibacterial proteins in male fruit fly reproductive tissues.
- To determine if these antibacterial proteins are transferred to females during mating.
- To assess the potential role of these proteins in protecting reproductive tracts and gametes from bacterial infection.
Main Methods:
- Performed Escherichia coli overlay assays on reproductive tissue extracts from wild-type and transgenic male fruit flies.
- Utilized native polyacrylamide gel electrophoresis (PAGE) and SDS-PAGE to analyze protein fractions.
- Identified proteins with antibacterial activity based on zone of inhibition.
Main Results:
- Detected a 28 kDa male accessory gland-derived protein with antibacterial activity.
- Identified two ejaculatory duct-derived proteins with antibacterial activity.
- One ejaculatory duct protein is likely andropin, a known 6 kDa antibacterial peptide. All three proteins are transferred to females during mating.
Conclusions:
- Male fruit flies possess and transfer antibacterial proteins via seminal fluid.
- These proteins can protect the male and female reproductive tracts, as well as eggs, from bacterial infections.
- Antibacterial proteins transferred before sperm may also protect sperm from bacterial invasion.
