Report on the 2 international molecular biosciences PhD and postdoc conference 2023: The emerging challenge - environmental impacts on human health.

The 2 International FEBS-IUBMB-ENABLE Molecular Biosciences PhD and Postdoc Conference was held from 23 to 25 November 2023 in Cologne, Germany. Over 240 participants from 31 different countries came together at the University of Cologne to follow the two-day scientific symposium and the career day. This year's topic was "The emerging challenge - environmental impacts on human health".

Specialized ommatidia of the polarization-sensitive dorsal rim area in the eye of monarch butterflies have non-functional reflecting tapeta.

Many insects exploit sky light polarization for navigation or cruising-course control. The detection of polarized sky light is mediated by the ommatidia of a small specialized part of the compound eye: the dorsal rim area (DRA). We describe the morphology and fine structure of the DRA in monarch butterflies (Danaus plexippus).

Homothorax switches function of Drosophila photoreceptors from color to polarized light sensors.

Different classes of photoreceptors (PRs) allow animals to perceive various types of visual information. In the Drosophila eye, the outer PRs of each ommatidium are involved in motion detection while the inner PRs mediate color vision. In addition, flies use a specialized class of inner PRs in the "dorsal rim area" of the eye (DRA) to detect the e-vector of polarized light, allowing them to exploit skylight polarization for orientation.