Drosophila melanogaster seminal fluid can protect the sperm of other males
Article first published online: 20 NOV 2008
© 2008 The Author. Journal compilation © 2008 British Ecological Society
Volume 23, Issue 1, pages 180–186, February 2009
How to Cite
Holman, L. (2009), Drosophila melanogaster seminal fluid can protect the sperm of other males. Functional Ecology, 23: 180–186. doi: 10.1111/j.1365-2435.2008.01509.x
- Issue published online: 16 JAN 2009
- Article first published online: 20 NOV 2008
- Received 11 July 2008; accepted 14 October 2008Handling Editor: Sara Lewis
- sexual conflict;
- sperm competition;
- viability staining
- 1Many internally-fertilizing animals produce seminal fluid which is transferred along with sperm during mating. Seminal fluid typically contains a diverse range of chemicals that coordinate sperm storage, moderate sperm motility, provide advantages in sexual selection and influence female physiology.
- 2Seminal fluid is well-studied in Drosophila melanogaster, a species in which it has been suggested to ‘incapacitate’ the sperm of rival males (e.g. by killing them) and thereby provide an advantage in sperm competition. This hypothesis has been tested several times over many years, but different studies have yielded conflicting conclusions. Here, I use fluorescent staining to directly measure the effects of D. melanogaster seminal fluid on the survival of sperm from the same male or from a rival. The results suggest that seminal fluid improves sperm survival, even if the sperm are from a different male. This study therefore provides strong evidence that seminal fluid does not kill rival sperm, and instead can actually protect them. This study also tested whether chemicals in the female reproductive tract harm sperm as in another Drosophila species, but found no evidence of this.
- 3These findings suggest that residual seminal fluid inside females could benefit the sperm of subsequent mates, affecting the outcome of sperm competition and influencing the evolution of ejaculates and mating systems.