Klaus Reinhardt

Key Research Interests
Curriculum vitae
Publications

Key Research Interests

Evolutionary Consequences of Sperm Ageing

Every cell decreases in function over time and sperm are no exception other than they may age even faster. Fertilisation and zygote viability critically depend on sperm age and in order to reproduce males must deliver functional, i.e. non-aged, sperm whereas females benefit from fertilising their eggs using recently produced or otherwise little undamaged sperm. The concept of a changing function of a sperm cell over its lifetime (i.e. sperm phenotype) challenges the view that reproductive differences are largely caused by postcopulatory sexual selection, i.e. by differences between individuals based on the gamete genotype. However, selection on preventing fertilisation with aged gametes may explain a large diversity of traits currently exclusively ascribed to sexual selection, such as multiple mating by both sexes, high sperm production rates, the delivery of dense ejaculates and non-fertilizing sperm, male and female sperm ejection, sexual coercion, as well as the production of showy visual signals and many cellular and nuclear repair mechanisms. Altering the sperm age distribution at any step during reproduction may be one origin of sexually selected traits and may explain presently observed paternity variation without assuming genetic incompatibility of gametes.

Sexual conflict: The evolution of traumatic insemination

Divergent evolutionary interests in males and females select for a wide range of reproductive traits including highly bizarre ones: Bedbug males copulate by piercing the body wall of the female. A unique female organ, the spermalege, acts to mediate these contaminations and has perhaps evolved in response to bacterial contaminations of the male intromittent organ. Divergent counteradaptations in females were predicted to cause speciation. This has led to an incredible set of double-mimicking characters in the African batbug Afrocimex constrictus: a) males mate with other males but have b) one type of defensive female genitalia. c) Females have polymorphic genitalia whereby those closest resembling the male receive fewest traumatic inseminations.

Genitalia evolution

Male but not female genitalia vary widely between species which has been proposed to arise from sexual selection. We are currently testing these ideas using bed bugs in which females have spatially separated mating and oviposition genitalia.

The ecology of the bedbug

I am broadly interested in the dispersal, population, chemical and thermal ecology of the bedbug both in terms of pure biological aspects as well as potential pest control applications.

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Curriculum vitae

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