Online via Microsoft Teams

Hosts: Prof Sarah Coulthurst & Prof Nicola Stanley-Wall 

Abstract: 

“Life is nothing but an electron looking for a place to rest,” quoted from Nobel Prize-winning biochemist Albert Szent-Györgyi, underscores the critical role of electron movement in all living systems. In this seminar, I will introduce the fundamental principles of extracellular electron transfer (EET), observed in unique microbes capable of exchanging electrons beyond their cell boundaries. Through four compelling examples, I will showcase my contributions to uncovering novel EET pathways, enhancing electron transfer efficiency at interfaces through bioengineering and material engineering, engineering electron flux for rapid biosensing, and crafting biohybrid systems for solar chemical synthesis. Additionally, I’ll outline research plans focused on engineering biology for environment, energy, and healthcare, all from the perspective of electron transfer. I invite engaging discussions and collaboration with the audience to further explore these exciting frontiers. 

Biography   

Dr. Lin Su is currently a Leverhulme Early Career Fellow at the University of Cambridge, where he has been working with the Reisner Lab in the Department of Chemistry since 2021. Lin holds a Ph.D. in biomedical engineering from Southeast University, which he obtained in 2021. His background is in bioelectrochemistry and synthetic biology, which he honed during a visit to Prof. Caroline Ajo-Franklin’s group at Lawrence Berkeley National Laboratory since 2016. Lin's research focuses on engineering electron transfer at microorganism-material interfaces, intending to develop biohybrid systems for semi-artificial photosynthesis and bioelectronic sensors for information exchange. 
https://scholar.google.com/citations?hl=en&user=XBwfd50AAAAJ 

Venue: New Seminar Room, James Hutton Institute, Invergowrie

Host: Emma Hardy

Abstract

Hemp (Cannabis sativa L.) is an extraordinarily versatile crop, with applications ranging from medicinal compounds to seed oil and fibre products. As a short-day plant, hemp flowering is tightly controlled by the photoperiod. However, substantial genetic variation exists for photoperiod sensitivity in C. sativa, and photoperiod-insensitive (“autoflower”) cultivars are available.

We identified Autoflower2 as a locus significantly associated with photoperiod-insensitive flowering in hemp. Autoflower2 contains an ortholog of the central flowering time regulator FLOWERING LOCUS T (FT). Extensive sequence divergence between alleles of CsFT1 was identified, including a duplication of CsFT1 in photoperiod insensitive cultivars.

This study reveals multiple independent origins of photoperiod insensitivity in C. sativa, supporting the likelihood of a complex domestication history in this species. We also show that genetic diversity in hemp is high, providing an important resource for targeted breeding efforts to generate cultivars better adapted to local conditions

Venue: The Murray Room CTIR 2.84 

Host: Dr Henry McSorley

Abstract 

The intestinal roundworm Heligmosomoides bakeri causes chronic infection in susceptible (C57Bl/6) mice; however, repeat (trickle) infection confers immunity and facilitates worm clearance. We show that this acquired immunity is associated with a strong local Th2 response, notably the enhanced production of intestinal granulomas containing eosinophils and macrophages bound to parasite-specific antibody. 

In the natural world rather than the laboratory setting, immune environments are more nuanced. We examined the impact of a mixed Th1 (inflammatory)/Th2 (wound healing) environment on trickle infection-induced immunity. The mixed immune environment resulted in high worm burdens and lower granuloma numbers. Granulomas had decreased proportions of key immune cells (eosinophils and macrophages) and an absence of antibody. Parasite-specific antibodies were also absent from the draining lymph nodes. These data confirm the importance of intestinal granulomas and parasite-specific antibody as worm clearance mechanisms. Our result also highlight why it may be more difficult to clear worms in the field than in the laboratory.

Venue: The Murray Room CTIR 2.84 

Host: Dr Dan Neill 

Biography   

Stephen is based at the Wellcome Sanger Institute where he leads a portfolio of pathogen genomic studies covering multiple bacterial species and ranging in scope from global surveillance to within host variation. He is Director of the Bill and Melinda Gates Foundation funded Global PneumococcalSequencing project that has sequenced and analysing the genomes of more than 31 thousand pneumococcal isolates, collected from 59 countries, before and after the introduction of pneumococcal conjugate vaccine. The Gates Foundation have also funded his team to perform a global genomic survey of the neonatal sepsis pathogen, Streptococcus agalactiae. 

After PhD and postdoctoral studies at the Universities of Warwick and Cambridge, Stephen joined the Wellcome Trust Sanger Institute in 1998 from where he has been engaged in the development of approaches to genome research and its application to the study of bacterial pathogens. 

Stephen has authored >250 publications including 27 review articles and 5 book chapters with 46694 citations and an H-index of 102 (for full listing see http://tinyurl.com/StephenBentleyScholar). 

Venue: Small Lecture Theatre, MSI

Host: Prof Dario Alessi

Abstract: The permeability barrier of nuclear pore complexes (NPCs) controls nucleocytoplasmic transport. It restricts inert macromolecules >30 kDa, but allows facilitated passage of nuclear transport receptor proteins (NTRs, e.g., importins and exportins) that shuttle cargoes in or out of the nucleus. The barrier can be described as a condensed protein-rich phase assembled from “cohesive” FG (Phe-Gly) repeat domains, which are long (~500 residues) intrinsically disordered regions at the central channel of NPCs. These FG domains include the most important Nup98 FG domain and several distinct subtypes, each comprising variable repeats and low complexity sequences.

The Nup98 FG domain comprises hydrophobic FG motifs, typically GLFG motifs, connected by more hydrophilic, uncharged spacers. These FG motifs bind NTRs passing NPCs. It was shown that the cohesive Nup98 FG domain phase-separates spontaneously from dilute aqueous solution to form gel-like phase (“FG phase”) with NPC-like selectivity: Such a condensed phase favours the partitioning of NTRs/NTR-cargo complexes, but excludes inert large proteins. However, the molecular details and determinants of this barrier property remained unclear. In particular, nanoscopic insight into the cohesive interactions has long been hampered by the sequence heterogeneity of the wild-type FG domain.

By systematically engineering the Nup98 FG domain, we identified several features in the sequence that are critical for the barrier property, for example, the frequency of FG motifs and the overall hydrophobicity of the domain. All of these correlate with the conserved features, suggesting that the FG domain is evolutionarily optimized for its barrier function. At one extreme of engineering, we obtained a variant composed of perfect repeats of 12 amino acid peptides, which still assembles into a barrier with exquisite transport selectivity. This barrier recapitulates importin- and exportin-mediated cargo transport and thus represents an ultimately simplified experimental model system. Such a system allowed us to overcome intrinsic challenges posed by the sequence heterogeneity of wild-type FG domains and to reveal the surprisingly fast local dynamics of cohesive interactions by high-resolution NMR spectroscopy on the FG phase.

The FG phase was initially thought to be an exotic form of biological matter. However, it is now clear that it is only a first example of a wide range of biomolecular condensates composed of sticky intrinsically disordered protein domains. My future work will involve investigating the regulatory mechanisms of these sticky domains, including how these regions are suppressed when they need to pass through the FG phase during nucleocytoplasmic transport.

Online via Microsoft Teams

Host: Dr Henry McSorley 

Abstract 

We have a major focus on immunobiology of plasmacytoid dendritic cells (pDCs), the dendritic cell subset known for its ability to produce large amounts of type I interferons (IFNs) in response to activation of endosomal toll-like receptors. On one hand, we are interested in exploring the pathogenic role of pDCs in different clinical contexts of autoreactive inflammation. For example, our group has previously shown crucial role of pDC-derived type I IFNs in discrete contexts like autoimmune disorders (viz. systemic lupus and psoriasis) and metabolic disorders (obesity associate adipose tissue inflammation). Recently, we have also been exploring pathogenic role of pDCs inneurodegenerative inflammatory contexts. Thus, we are aiming to expand our understanding about the pDC-driven pathogenic continuum across discrete clinical contexts of autoreactive inflammation. On the other hand, our laboratory is engaged in exploring the cell biology of human pDCs with an aim to discover novel regulatory pathways and potential therapeutic targets. Our interest in the cell biology of human pDCs has also recently been veered to exploring the role of Piezo1 mechanosensors inregulation of cellular functions in pDCs as well as other human immune cells. The present talk plans to inform the audience about how our laboratory has contributed to the aforementioned areas and how does the future trajectory of our research look like. 

Venue: New Seminar Room, James Hutton Institute, Invergowrie

Host: Prof Robbie Waugh

Abstract

Modern crops are derived from domestication and improvement through selective breeding over many years. In the last few decades, many breeding programmes experience an accelerated genetic progress due to the use of molecular markers. Breeding targets, such as yield, flowering time, plant architecture and resource use efficiencies, are considered to be complex quantitative traits. The genetic architecture of complex traits can be challenging to disentangle due to their polygenic nature (many genes of small effects) and presence of genetic (epistasis) and other (genetic x environment x management) interactions. Therefore, complex traits are best studied from the perspective of quantitative genetics. This talk will explore multiple research projects that span across the timescale of plant breeding. What are the selection intensities, constraints and impacts during crop domestication? How can pre-breeding programmes introgress exotic genetic diversity from diverse sources in a more effective way? What are the strategies for breeding novel crops and how can these breeding programmes benefit from modern technologies? Knowledge gained from these research projects can contribute toward guiding future plant breeding for better efficiency, sustainability and climate resilience.

Venue: MSI-SLT  

Host: Prof. Rastko Sknepnek 

Abstract

Living systems adopt a diversity of curved and highly dynamic shapes. These diverse morphologies appear on many length-scales, from cells to tissues and organismal scales. The common driving force for these dynamic shape changes are contractile stresses generated by myosin motors in the cell cytoskeleton, that converts chemical energy into mechanical work. A good understanding of how contractile stresses in the cytoskeleton arise into different 3D shapes and what are the shapeselection rules that determine their final configurations is still lacking. To obtain insight into the relevant physical mechanisms, we recreate the actomyosin cytoskeleton in-vitro, with precisely controlled composition and initial geometry. A set of actomyosin gel discs, intrinsically identical but of variable initial geometry, dynamically self-organize into a family of 3D shapes, such as domes and wrinkled shapes, without the need for specific pre-programming or additional regulation. Shape deformation is driven by the spontaneous emergence of stress gradients driven by myosin and is encoded in the initial disc radius to thickness aspect ratio, which may indicate shaping scalability. Our results suggest that, while the dynamical pathways may depend on the detailed interactions between the different microscopic components within the gel, the final selected shapes obey the general theory of elastic deformations of thin sheets. Altogether, our results emphasize the importance for the emergence of active stress gradients for buckling driven shape deformations and provide novel insights on the mechanically induced spontaneous shape transitions in contractile active matter, revealing potential shared mechanisms with living systems across scales.  

Venue: Murray Seminar Room, Discovery Centre 

Host: Dr Jens Januschke

Abstract: Biomolecular condensates have emerged as a common cellular feature that generates unique intracellular biochemical environments without an encapsulating membrane. Many condensates have been identified in early animal development including: P granules in C. elegans; Balbiani bodies in Xenopus and zebrafish; and processing bodies (P bodies) in Drosophila. Despite considerable research, understanding of the biological function of condensates in vivo remains limited. We focus on mRNA and protein assembly, and disassembly, in response to developmental and environmental stimuli in Drosophila egg chambers and early embryos. Our most recent work show that the integrity of P bodies regulates the translation of mRNA.

Venue: New Seminar Room, James Hutton Institute, Invergowrie 

Host: Professor Paul Birch

Abstract

The cambium is the stem cell niche in eudicot plants from which xylem and phloem tissues are derived through tightly controlled cell division and differentiation. However, the specific factors that maintain cambial stem cells have been elusive. We reveal that the TDIF-PXY signalling pathway, known to regulate cell division and differentiation in the cambium, controls the expression of PLTtranscription factors within the Arabidopsis thaliana cambial zone. Our data demonstrate that these PLT genes constitute the long-sought-after stem cell identity factors within the actively dividing cambial meristem.

Interestingly, while monocot species lack a cambium, they retain homologs of these regulatory genes. Ongoing efforts in barley reveal surprising conservation, yet subfunctionalization of TDIF-PXY signalling. Our analysis suggests repurposing of this signalling pathway in the different angiosperm lineages to control distinct zones of cell proliferation. This work thus provides insight into the regulation of different stem architectures in monocots and dicots.