1) Sperm biology

klaus pic1Using advanced laser and fluorescence microscopy, as well as experimental manipulations and experimental evolution we study how bacteria, oxidative stress, the female immune system, CO2 and male diet affect sperm traits, and how these effects shape trait evolution in males and females. Two examples 1) Male bedbugs transfer microbes to the female that kill sperm. This has lead to the evolution of antibiotic ejaculates which reduces the microbe-imposed sperm mortality. 2) Insect sperm accumulate deadly reactive oxygen species (ROS) during their metabolism. Female insects interfere with sperm metabolism and so reduce the sperm’s own ROS production and extend the sperm lifespan. Picture left: Live sperm (green) from bedbugs surrounding female cells (stained red)

Further reading:

NEVER TAKE SPERM OUT OF CONTEXT! A review on environmental effects on all kinds of sperm function, published in A Rev Ecol Evol Syst.

NO MORE NON-BLIND? See our cautionary tale on measuring samples in a non-blind way. Front Ecol Evol link

GOOD-GENES SPERM, REALLY? – our proof-of-concept paper to characterise sperm metabolism label-free using two-photon microscopy appeared in J Roy Soc Interface.

SPERM HYGIENE – our paper on an antibiotic substance in the semen of bedbugs that restores viability of sperm when attacked by sexually transmitted microbes (press coverage)

CELIBACY SUCKS – our new paper showing that female transcriptomic responses are directed against aged sperm, but not so much against their genotype (press relases in German or English)

BAD SPERM – our paper showing an increase in sperm oxygen radicals is correlated with infertility

TAMING THE SPERM – our paper showing that females reduce the metabolic rate of stored sperm and thereby reduce the production of toxic oxygen radicals