This month has also seen the publication of another paper of mine (in collaboration with Leigh Simmons), again in Proceedings B, but this time using micro-CT to examine the timing and location of female copulatory wounding in Callosobruchus maculatus. For this project I performed micro-CT scans of 19 mating pairs of C. maculatus that had been flash-frozen in liquid Nitrogen at different stages of mating. We then used these scans to examine the interactions between male and female genitalia during mating, and visualise these interactions in unprecedented detail.
Importantly, we were able to use the scan data to detect copulatory wounding of females without having to wait for an immune response, which is needed when assessing wounding using a light microscope. We could therefore use the micro-CT technique to examine how tract damage accumulates during mating, and how the timing of damage relates to female mating behaviour.
This paper is also a showcase for the power of micro-CT to aid our understanding of reproductive behaviour and morphology, and I hope it inspires more people to use this technique in the future!
Please follow this link, or the relevant link on the publications page, to read the full paper.
I'm very excited to say that my newest paper was published online a few weeks ago in Proceedings B, looking at sexual conflict in the seed beetle Callosobruchus maculatus. This is the first paper from my work at UWA, and is the result of a collaboration with several researchers at UWA (Emile van Lieshout, Kathryn McNamara & Leigh Simmons) as well as Göran Arnqvist at Uppsala University. The project benefitted especially from the use of C. maculatus lines that Göran has been maintaining at Uppsala for many years.
In the paper we show that there has been correlated evolution between the size of the male penis spines and three defensive female adaptations (the thickness of the female reproductive tract lining, and two measures of female immune activity), across 13 C. maculatus population that have been isolated in the lab for over 100 generations. Importantly, we also show that the amount of copulatory wounding females receive during mating is related to the relative thickness of the female reproductive tract in relation to male spine length (as shown in the image below). This is strong evidence that males and females of this species are locked in an evolutionary arms race driven by sexual conflict.
Follow the link here to read the paper, or go to the publications page for the pdf.