Serial electron diffraction (SED) and serial synchrotron nano-crystallography (nano-SSX) are just-emerging methods in structural biology, whereby data are collected from protein nanocrystals using a sub-micron-sized electron or X-ray beam, respectively. These methods are set to lead the future of nano-crystallography, given their cost-effectiveness and the small amount of sample required. Combining the expertise of the Colletier, Lereclus and Miller teams, the project will address four issues of fundamental importance to further advance the SED and nano-SSX methodologies. Specifically, we will (i) test if the methods can be applied to solve nano-crystalline protein structures in the cellular environment (i.e. in vivo); (ii) determine what is the smallest crystal size that can be probed by SED and nano-SSX; (iii) develop an in vivo crystallization approach based on recombinant expression of fusion proteins in the crystalliferous bacterium Bacillus thuringiensis; and (iv) offer a proof of feasibility for time-resolved SED experiments on macromolecular nanocrystals. Results from the SNaX project will allow to explore the boundaries of SED and nano-SSX, and to develop their full promises for nano-crystallography.

‘Sex_Coevolution’ will reconstruct the genetic basis of escalation of armaments between the sexes. Decades of research established how sexual conflict drives sexually antagonistic coevolution at the phenotypic level, yet we know little about the genetic mechanisms underlying this escalation. This is primarily due to the scarcity of models that are amenable for studying both genetics and sexual conflict. Therefore, identifying the loci undergoing conflict has proven difficult, thus impeding our understanding of their role in shaping phenotypic divergence of the sexes during development, their evolutionary dynamics, the frequencies of their allelic variants in natural populations and how they affect male and female fitness. Water striders are prominent models for sexual conflict studies and are tractable for developmental genetic and genomic experimentation. ‘Sex_Coevolution’ will use phenotypically divergent populations and hybridizing species pairs to identify the loci underlying sexually antagonistic armaments, how these loci shape male and female phenotypes during development, and how their allele frequencies change under sexual conflict. To do this, we will: (i) use genetic mapping to systematically identify the loci underlying a set of male and female sexually antagonistic traits, and functionally determine how these loci build these traits during development, (ii) use experimental evolution and Evolve-and-Resequence approaches to track the changes in the frequencies of sexually antagonistic loci under a selective regime that intensifies conflict, and (iii) use fieldwork and population genetics to determine allele frequencies of the identified loci in natural populations known to harbour conspicuous variation in sexually antagonistic traits. By integrating multiple approaches, ‘Sex_Coevolution’ will allow us to achieve a thorough match between the observed escalation of armaments at the phenotypic level and its underlying changes at the genetic level.