Towards a better understanding of the origins of microlens arrays in Mesozoic ophiuroids and asteroids

Echinoderms are characterized by a calcite endoskeleton with a unique microstructure, which is optimized for multiple functions. For instance, some light-sensitive ophiuroids (Ophiuroidea) and asteroids (Asteroidea) possess skeletal plates with multi-lens arrays that are thought to act as photosensory organs. The origins of these lens-like microstructures have long been unclear. It was recently proposed that the complex photosensory systems in certain modern ophiuroids and asteroids could be traced back to at least the Late Cretaceous (ca. 79 Ma). Here, we document similar structures in ophiuroids and asteroids from the Early Cretaceous of Poland (ca. 136 Ma) that are approximately 57 million years older than the oldest asterozoans with lens-like microstructures described thus far. We use scanning electron microscopy, synchrotron tomography, and electron backscatter diffraction combined with focused ion beam microscopy to describe the morphology and crystallography of these structures in exceptional detail. The results indicate that, similar to Recent light-sensitive ophiuroids, putative microlenses in Cretaceous ophiuroids and asteroids exhibit a shape and crystal orientation that would have minimized spherical aberration and birefringence. We suggest that these lens-like microstructures evolved by secondary deposition of calcite on pre-existing porous tubercles that were already present in ancestral Jurassic forms

Towards a better understanding of the origins of microlens arrays in Mesozoic ophiuroids and asteroids

Echinoderms are characterized by a calcite endoskeleton with a unique microstructure, which is optimized for multiple functions. For instance, some light-sensitive ophiuroids (Ophiuroidea) and asteroids (Asteroidea) possess skeletal plates with multi-lens arrays that are thought to act as photosensory organs. The origins of these lens-like microstructures have long been unclear. It was recently proposed that the complex photosensory systems in certain modern ophiuroids and asteroids could be traced back to at least the Late Cretaceous (ca. 79 Ma). Here, we document similar structures in ophiuroids and asteroids from the Early Cretaceous of Poland (ca. 136 Ma) that are approximately 57 million years older than the oldest asterozoans with lens-like microstructures described thus far. We use scanning electron microscopy, synchrotron tomography, and electron backscatter diffraction combined with focused ion beam microscopy to describe the morphology and crystallography of these structures in exceptional detail. The results indicate that, similar to Recent light-sensitive ophiuroids, putative microlenses in Cretaceous ophiuroids and asteroids exhibit a shape and crystal orientation that would have minimized spherical aberration and birefringence. We suggest that these lens-like microstructures evolved by secondary deposition of calcite on pre-existing porous tubercles that were already present in ancestral Jurassic forms

EUROREG – University of Warsaw, LP

This report presents the draft final results of an Applied Research Project conducted within the framework of the ESPON 2013 Programme, partly financed by the European Regional Development Fund. The partnership behind the ESPON Programme consists of the EU Commission and the Member States of the EU27, plus Iceland, Liechtenstein, Norway and Switzerland. Each partner is represented in the ESPON Monitoring Committee. This report does not necessarily reflect the opinion of the members of the Monitoring Committee. Information on the ESPON Programme and projects can be found on www.espon.eu The web site provides the possibility to download and examine the most recent documents produced by finalised and ongoing ESPON projects. This basic report exists only in an electronic version. © ESPON & EUROREG- Centre for Europea

List of authors

This report presents the draft final results of an Applied Research Project conducted within the framework of the ESPON 2013 Programme, partly financed by the European Regional Development Fund. The partnership behind the ESPON Programme consists of the EU Commission and the Member States of the EU27, plus Iceland, Liechtenstein, Norway and Switzerland. Each partner is represented in the ESPON Monitoring Committee. This report does not necessarily reflect the opinion of the members of the Monitoring Committee. Information on the ESPON Programme and projects can be found on www.espon.eu The web site provides the possibility to download and examine the most recent documents produced by finalised and ongoing ESPON projects. This basic report exists only in an electronic version. © ESPON & EUROREG- Centre for Europea

List of authors

This report presents the draft final results of an Applied Research Project conducted within the framework of the ESPON 2013 Programme, partly financed by the European Regional Development Fund. The partnership behind the ESPON Programme consists of the EU Commission and the Member States of the EU27, plus Iceland, Liechtenstein, Norway and Switzerland. Each partner is represented in the ESPON Monitoring Committee. This report does not necessarily reflect the opinion of the members of the Monitoring Committee. Information on the ESPON Programme and projects can be found on www.espon.eu The web site provides the possibility to download and examine the most recent documents produced by finalised and ongoing ESPON projects. This basic report exists only in an electronic version. © ESPON & EUROREG- Centre for Europea

Recovery of Extra-Radical Fungal Peptides Amenable for Shotgun Protein Profiling in Arbuscular Mycorrhizae

International audienceIn arbuscular mycorrhizal symbiosis, the belowground mycelium that develops into the soil, not only provides extensive pathways for nutrient fluxes, the occupation of different niches, and dispersal of propagules, but also has strong influences upon biogeochemical cycling. By providing a valuable overview of expression changes of most proteins, shotgun proteomics can help decipher key metabolic pathways involved in the functioning of fungal mycelia. In this protocol, we describe the combination of extra-radical mycelium growth systems with gel-based extraction of fungal peptides amenable for shotgun protein profiling, which allows gaining information about the extra-radical proteom