X-ray micro-CT scanning reveals temporal separation of male harm and female kicking during traumatic mating in seed beetles

Dougherty, Liam R ORCID: 0000-0003-1406-0680 and Simmons, Leigh W (2017) X-ray micro-CT scanning reveals temporal separation of male harm and female kicking during traumatic mating in seed beetles. Proceedings of the Royal Society B: Biological Sciences, 284 (1856). 20170550-.

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Abstract

In the seed beetle Callosobruchus maculatus, the male intromittent organ is covered in sharp spines that pierce the female copulatory tract wall during mating. Although the fitness consequences of traumatic mating are well studied in this species, we know much less about how the male and female genitalia interact during mating. This is partly due to the fact that genital interactions occur primarily inside the female, and so are difficult to observe. In this study, we use X-ray micro-CT scanning to examine the proximate mechanisms of traumatic mating in C. maculatus in unprecedented detail. We show that this technique can be used to identify female tissue damage before the melanization of wound sites. We visualize the positioning of the male intromittent organ inside the female copulatory tract during mating, and show how this relates to tract wounding in three dimensions. By scanning pairs flash-frozen at different times during mating, we show that significant tract wounding occurs before the onset of female kicking. There is thus some degree of temporal separation between the onset of wounding and the onset of kicking, which supports recent suggestions that kicking is not an effective female counter-adaptation to reduce copulatory wounding in this species. We also present evidence that the sharp teeth protruding from the female tract wall are able to pierce the spermatophore as it is deposited, and may thus function to aid sperm release.

Item Type:	Article
Uncontrolled Keywords:	Callosobruchus maculatus, copulatory wounding, genitalia, sexual conflict, traumatic mating, X-ray micro-CT
Depositing User:	Symplectic Admin
Date Deposited:	17 Apr 2019 14:32
Last Modified:	19 Jan 2023 01:12
DOI:	10.1098/rspb.2017.0550
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3029022