Biology subjects

Conrady, M.

Publications and source records attributed to Conrady, M..

5 recordsLinked to original sources

bioRxiv2023

A structural competition involving WDR5 times circadian oscillations

In the mammalian circadian clock, the transcription factor BMAL1/CLOCK cycles between an active state recruiting co-activators like MLL1, and repressed states associated with the clock proteins Period1/2 (PER1/2) and Cryptochrome1/2 (CRY1/2). The MLL1 complex component WDR5 was also found in a repressive PER complex, but the roles of WDR5-PER interactions are unknown. Here we show that WDR5 directly binds to the C-terminal CRY binding domain (CBD) regions of PER1 and PER2. PER2 binds WDR5 via a WDR5 binding (WBM) motif within the PER2/CRY interface, imposing a molecular choice between PER2/WDR5- and PER2/CRY complexes. PER1 predominantly binds WDR5 via a WDR5 interacting (WIN) motif outside the CBD and exhibits a 15-fold higher WDR5 affinity than PER2. Thereby PER1 can form trimeric PER1WIN/WDR5/RbBP5WBM - and PER1/WDR5/CRY complexes as potential transition states between activating MLL1WIN/WDR5/RbBP5WBM - and repressive PER/CRY complexes. Overexpressing WDR5 in mammalian cells increases the circadian amplitude, whereas a compound targeting the WIN motif binding site of WDR5 weakens PER1-WDR5 interactions and shortens the circadian oscillation period by 2 to 3 hours. Together, our studies uncover WDR5 as direct PER interaction partner at the interface between active- and repressed states of BMAL1/CLOCK and suggest a functional role of WDR5 and its WIN site interactions in the mammalian clock by both enhancing circadian oscillations and creating a temporal delay.

biochemistry↗

bioRxiv2023

Plants cultivated for ecosystem restoration can evolve towards a domestication syndrome

The UN Decade on Ecosystem Restoration calls for upscaling restoration efforts, but many terrestrial restoration projects are constrained by seed availability. To overcome these constraints, wild plants are increasingly propagated on farms to produce seeds for restoration projects. During on-farm propagation, the plants face non-natural conditions with different selection pressures, and they might evolve adaptations to cultivation that parallel those of agricultural crops, which could be detrimental to restoration efforts. To test this, we compared traits of 19 species grown from wild-collected seeds to those from their farm-propagated offspring of up to four cultivation generations, produced by two European seed growers, in a common garden experiment. We found that some plants rapidly evolved across cultivated generations towards increased size and reproduction, lower within-species variability, and more synchronized flowering. In one species, we found evolution towards less seed shattering. These trait changes are typical signs of the crop domestication syndrome, and our study demonstrates that it can also occur during cultivation of wild plants, within only few cultivated generations. However, there was large variability between cultivation lineages, and the observed effect sizes were generally rather moderate, which suggests that the detected evolutionary changes are unlikely to compromise farm-propagated seeds for ecosystem restoration. To mitigate the potential negative effects of unintended selection, we recommend to limit the maximum number of generations the plants can be cultivated without replenishing the seed stock from new wild collections. Significance StatementGlobally upscaling demands for native seeds for ecosystem restoration can be covered by agricultural seed propagation. Yet, agricultural practice can unintentionally select for specific traits and reduce adaptive variability, which could affect plant performance once sown back to the wild. We show, across 19 wild species, two seed producers and up to four consecutive cultivated generations, that some plants under cultivation evolved higher vigor, reduced adaptive variability, synchronized flowering and in one case, reduced seed shattering. Yet, there were substantial differences among cultivation lineages, with negligible changes in most, and large changes only in a few cases. Substantial unintended evolution in cultivation is thus rather an exception than the rule.

ecology↗

bioRxiv2022

Rapid evolution of flower phenology and clonality in restored populations of multiple grassland species

Restoration of terrestrial ecosystems often requires re-introduction of plants. In restored sites, the plants often face environment that differs from the one in natural populations. This which can affect plant traits, reduce performance and impose novel selection pressures. As a response, restored populations might rapidly evolve and adapt to the novel conditions. This may enhance population survival and contribute to restoration success, but has been rarely tested so far. Here, we focused on populations of three grassland species restored 20 years ago (Galium wirtgenii, Inula salicina and Centaurea jacea) by the transfer of green hay, and compared them with populations that were source of the hay. We measured plants both in-situ, and in common garden under control and three stress conditions. In-situ, restored and natural populations differed in flowering phenology in two out of the three species. In the common garden, plants of the restored population flowered earlier (in Galium) or showed increased plasticity of clonal propagation in response to clipping (Inula). Both these traits suggest rapid adaptation to the contrasting mowing regimes in restored in comparison to the natural donor sites. In Centaurea, we detected no differentiation, neither in-situ, nor in the common garden. Rapid evolution in two out of three species indicates that evolution in restoration may be rather common, yet not ubiquitous across species.

evolutionary biology↗

bioRxiv2021

Evolution during seed production for ecological restoration? A molecular analysis of 19 species finds only minor genomic changes

A growing number of restoration projects require large amounts of seeds. As harvesting natural populations cannot cover the demand, wild plants are often propagated in large-scale monocultures. There are concerns that this cultivation process may cause genetic drift and unintended selection, which would alter the genetic properties of the cultivated populations and reduce their genetic diversity. Such changes could reduce the pre-existing adaptation of restored populations, and limit their adaptability to environmental change. We used single nucleotide polymorphism (SNP) markers and a pool-sequencing approach to test for genetic differentiation and changes in gene diversity during cultivation in 19 wild grassland species, comparing the source populations and up to four consecutive cultivation generations grown from these sources. We then linked the magnitudes of genetic changes to the species breeding systems and seed dormancy, to understand the roles of these traits in genetic change. The propagation of native seeds for ecosystem restoration changed the genetic composition of the cultivated generations only moderately. The genetic differentiation we observed as a consequence of cultivation was much lower than the natural genetic differentiation between different source regions, and the propagated generations harbored even higher gene diversity than wild-collected seeds. Genetic change was stronger in self-compatible species, probably as a result of increased outcrossing in the monocultures. Synthesis and applicationsOur study indicates that large-scale seed production maintains the genetic integrity of natural populations. Increased genetic diversity may even increase the adaptive potential of propagated seeds, which makes them especially suitable for ecological restoration. However, we have been working with seeds from Germany and Austria, where the seed production is regulated and certified. Whether other seed production systems perform equally well remains to be tested.

ecology↗

bioRxiv2020

The choice of plant provenance for ecological restoration affects pollinator network

The selection of plant provenance for ecological restoration is an intensively debated topic. Throughout this debate, arguments mostly focus on plant performance, but little attention is paid to the effects of provenance on other members of the restored ecosystem. On the other hand, in restoration projects that focus specifically on supporting interacting biota, for example flower stripes among fields to support pollinators, the provenance choice is often not considered, partly because the effect of provenance on pollinators is unknown. In this pioneering case study, we tested whether pollinators differentiate between experimental plant communities of different provenances. We established experimental plant communities with the same species composition but with plants originating from three different provenances. We then recorded plant phenology and observed pollinators and flower visitors interacting with these experimental communities and related the pollinator visitation to the provenance identity. The provenances of the experimental plant communities had a strong and significant effect on the diversity and abundance of flower-pollinator interactions, with one provenance interacting twice as often as the other two provenances. The effect was driven by the differences in flowering phenology among provenances. Synthesis and applicationsPlant provenances substantially differ in their interactions with local pollinators. Therefore, the selection of plant provenance should be considered when planning restoration projects for the support of pollinators.

ecology↗