Postdoc

d.rogers@ic.ac.uk

My research aims to identify the molecular systems regulating mating success in both male and female mosquitoes.

Males. Proteins produced by the male accessory glands and transferred to females in the seminal fluid have been shown to be important regulators of mating success in several species of insects. However, little is known about these proteins in mosquitoes. We have identified over 60 secreted proteins produced in the male accessory glands, and we have demonstrated that many of these proteins are transferred to females during copulation. One of these proteins, a glutamine-rich molecule called Plugin, acts as a substrate for an accessory-gland specific transglutaminase enzyme. Cross-linking of Plugin by the transglutaminase results in the coagulation of the seminal fluid into a solid “mating plug”. This mating plug promotes the correct storage of sperm in the female spermatheca and therefore plays a crucial role in determining the success of a mating. Tests of the functions of other male accessory gland proteins are currently underway.

Females. Mating induces a number of important behavioural and physiological changes in female mosquitoes including the inhibition of remating and the stimulation of oviposition. As a first step towards understanding the molecular bases of these changes, we carried out a microarray analysis of the transcriptional changes induced by mating in female An. gambiae. We identified 141 unique transcripts showing a greater than 2-fold response to mating. Most of these changes took place within the lower female reproductive tract (the spermatheca, where sperm are stored; and the atrium where the mating plug is digested). We are currently working to determine the specific roles of these gene products in the female mating response.