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8. Resprouting grasses are associated with less frequent fire than seeders

Author

Simpson, Kimberley J, Jardine, Emma C, Archibald, Sally, Forrestel, Elisabeth J, Lehmann, Caroline ER, Thomas, Gavin H, and Osborne, Colin P

Subjects
Climate Change Impacts and Adaptation, Biological Sciences, Ecology, Plant Biology, Environmental Sciences, Ecosystem, Fires, Phylogeny, Plant Leaves, Plants, Poaceae, bud position, drought, fire frequency, fire intensity, life history, photosynthetic pathway, traits, Agricultural and Veterinary Sciences, Plant Biology & Botany, Plant biology, Climate change impacts and adaptation, Ecological applications
Abstract

Plant populations persist under recurrent fire via resprouting from surviving tissues (resprouters) or seedling recruitment (seeders). Woody species are inherently slow maturing, meaning that seeders are confined to infrequent fire regimes. However, for grasses, which mature faster, the relationships between persistence strategy and fire regime remain unknown. Globally, we analysed associations between fire regimes experienced by hundreds of grass species and their persistence strategy, within a phylogenetic context. We also tested whether persistence strategies are associated with morphological and physiological traits. Resprouters were associated with less frequent fire than seeders. Whilst modal fire frequencies were similar (fire return interval of 4-6 yr), seeders were restricted to regions with more frequent fire than resprouters, suggesting that greater competition with long-lived resprouters restricts seeder recruitment and survival when fire is rare. Resprouting was associated with lower leaf N, higher C:N ratios and the presence of belowground buds, but was unrelated to photosynthetic pathway. Differences between the life histories of grasses and woody species led to a contrasting prevalence of seeders and resprouters in relation to fire frequency. Rapid sexual maturation in grasses means that seeder distributions, relative to fire regime, are determined by competitive ability and recruitment, rather than time to reproductive maturity.

Published
2021

9. Elucidation of a sialic acid metabolism pathway in mucus-foraging Ruminococcus gnavus unravels mechanisms of bacterial adaptation to the gut.

Author

Bell, Andrew, Brunt, Jason, Crost, Emmanuelle, Vaux, Laura, Nepravishta, Ridvan, Owen, C David, Latousakis, Dimitrios, Xiao, An, Li, Wanqing, Chen, Xi, Walsh, Martin A, Claesen, Jan, Angulo, Jesus, Thomas, Gavin H, and Juge, Nathalie

Subjects
Mucus, Animals, Mice, Inbred C57BL, Humans, Mice, Ruminococcus, N-Acetylneuraminic Acid, Neuraminidase, Oxo-Acid-Lyases, Glycoproteins, Polysaccharides, Mucins, Recombinant Proteins, Adaptation, Physiological, Metabolic Networks and Pathways, Gastrointestinal Microbiome, Clostridiales, Nutrition, Oral and gastrointestinal, Microbiology, Medical Microbiology
Abstract

Sialic acid (N-acetylneuraminic acid (Neu5Ac)) is commonly found in the terminal location of colonic mucin glycans where it is a much-coveted nutrient for gut bacteria, including Ruminococcus gnavus. R. gnavus is part of the healthy gut microbiota in humans, but it is disproportionately represented in diseases. There is therefore a need to understand the molecular mechanisms that underpin the adaptation of R. gnavus to the gut. Previous in vitro research has demonstrated that the mucin-glycan-foraging strategy of R. gnavus is strain dependent and is associated with the expression of an intramolecular trans-sialidase, which releases 2,7-anhydro-Neu5Ac, rather than Neu5Ac, from mucins. Here, we unravelled the metabolism pathway of 2,7-anhydro-Neu5Ac in R. gnavus that is underpinned by the exquisite specificity of the sialic transporter for 2,7-anhydro-Neu5Ac and by the action of an oxidoreductase that converts 2,7-anhydro-Neu5Ac into Neu5Ac, which then becomes a substrate of a Neu5Ac-specific aldolase. Having generated an R. gnavus nan-cluster deletion mutant that lost the ability to grow on sialylated substrates, we showed that-in gnotobiotic mice colonized with R. gnavus wild-type (WT) and mutant strains-the fitness of the nan mutant was significantly impaired, with a reduced ability to colonize the mucus layer. Overall, we revealed a unique sialic acid pathway in bacteria that has important implications for the spatial adaptation of mucin-foraging gut symbionts in health and disease.

Published
2019

26. Genome Sequence of the Tsetse Fly (Glossina morsitans): Vector of African Trypanosomiasis

Author

Initiative, International Glossina Genome, Attardo, Geoffrey M, Abila, Patrick P, Auma, Joanna E, Baumann, Aaron A, Benoit, Joshua B, Brelsfoard, Corey L, Ribeiro, José MC, Cotton, James A, Pham, Daphne QD, Darby, Alistair C, Van Den Abbeele, Jan, Denlinger, David L, Field, Linda M, Nyanjom, Steven RG, Gaunt, Michael W, Geiser, Dawn L, Gomulski, Ludvik M, Haines, Lee R, Hansen, Immo A, Jones, Jeffery W, Kibet, Caleb K, Kinyua, Johnson K, Larkin, Denis M, Lehane, Michael J, Rio, Rita VM, Macdonald, Sandy J, Macharia, Rosaline W, Malacrida, Anna R, Marco, Heather G, Marucha, Kevin K, Masiga, Daniel K, Meuti, Megan E, Mireji, Paul O, Obiero, George FO, Koekemoer, Jacobus JO, Okoro, Chinyere K, Omedo, Irene A, Osamor, Victor C, Balyeidhusa, Apollo SP, Peyton, Justin T, Price, David P, Quail, Michael A, Ramphul, Urvashi N, Rawlings, Neil D, Riehle, Michael A, Robertson, Hugh M, Sanders, Mandy J, Scott, Maxwell J, Dashti, Zahra Jalali Sefid, Snyder, Anna K, Srivastava, Tulika P, Stanley, Eleanor J, Swain, Martin T, Hughes, Daniel ST, Tarone, Aaron M, Taylor, Todd D, Telleria, Erich L, Thomas, Gavin H, Walshe, Deirdre P, Wilson, Richard K, Winzerling, Joy J, Acosta-Serrano, Alvaro, Aksoy, Serap, Arensburger, Peter, Aslett, Martin, Bateta, Rosemary, Benkahla, Alia, Berriman, Matthew, Bourtzis, Kostas, Caers, Jelle, Caljon, Guy, Christoffels, Alan, Falchetto, Marco, Friedrich, Markus, Fu, Shuhua, Gäde, Gerd, Githinji, George, Gregory, Richard, Hall, Neil, Harkins, Gordon, Hattori, Masahira, Hertz-Fowler, Christiane, Hide, Winston, Hu, Wanqi, Imanishi, Tadashi, Inoue, Noboru, Jonas, Mario, Kawahara, Yoshihiro, Koffi, Mathurin, Kruger, Adele, Lawson, Daniel, Lehane, Stella, Lehväslaiho, Heikki, Luiz, Thiago, Makgamathe, Mmule, Malele, Imna, Manangwa, Oliver, Manga, Lucien, and Megy, Karyn

Subjects
Vector-Borne Diseases, Genetics, Prevention, Infectious Diseases, Biotechnology, 2.2 Factors relating to the physical environment, Aetiology, Infection, Good Health and Well Being, Animals, Blood, Feeding Behavior, Female, Genes, Insect, Genome, Insect, Insect Proteins, Insect Vectors, Microbiota, Molecular Sequence Annotation, Molecular Sequence Data, Reproduction, Salivary Glands, Sensation, Sequence Analysis, DNA, Symbiosis, Trypanosoma, Trypanosomiasis, African, Tsetse Flies, Wolbachia, International Glossina Genome Initiative, General Science & Technology
Abstract

Tsetse flies are the sole vectors of human African trypanosomiasis throughout sub-Saharan Africa. Both sexes of adult tsetse feed exclusively on blood and contribute to disease transmission. Notable differences between tsetse and other disease vectors include obligate microbial symbioses, viviparous reproduction, and lactation. Here, we describe the sequence and annotation of the 366-megabase Glossina morsitans morsitans genome. Analysis of the genome and the 12,308 predicted protein-encoding genes led to multiple discoveries, including chromosomal integrations of bacterial (Wolbachia) genome sequences, a family of lactation-specific proteins, reduced complement of host pathogen recognition proteins, and reduced olfaction/chemosensory associated genes. These genome data provide a foundation for research into trypanosomiasis prevention and yield important insights with broad implications for multiple aspects of tsetse biology.

Published
2014

27. Stereoselective synthesis of an advanced transdecalin intermediate towards the total synthesis of anthracimycin.

Author

Jeanmard, Laksamee, Lodovici, Giacomo, George, Ian, Bray, Joshua T. W., Whitwood, Adrian C., Thomas, Gavin H., Fairlamb, Ian J. S., Unsworth, William P., and Clarke, Paul A.

Subjects
NATURAL products, STEREOCHEMISTRY
Abstract

Progress towards the total synthesis of the macrolide natural product anthracimycin is described. This new approach utilises an intermolecular Diels-Alder strategy followed by epimeirsation to form the key trans-decalin framework. The route culminates in the stereoselective synthesis of an advanced tricyclic lactone intermediate, containing five contiguous sterogenic centres with the correct relative and absolute stereochemistry required for the anthracimycin core motif. [ABSTRACT FROM AUTHOR]

Published
2024
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33. Innovation and elaboration on the avian tree of life

Author

Guillerme, Thomas, primary, Bright, Jen A., additional, Cooney, Christopher R., additional, Hughes, Emma C., additional, Varley, Zoë K., additional, Cooper, Natalie, additional, Beckerman, Andrew P., additional, and Thomas, Gavin H., additional

Published
2023
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45. Flipping the switch: dynamic modulation of membrane transporter activity in bacteria

Author

Elston, Rory, Mulligan, Christopher, Thomas, Gavin H., Elston, Rory, Mulligan, Christopher, and Thomas, Gavin H.

Abstract

The controlled entry and expulsion of small molecules across the bacterial cytoplasmic membrane is essential for efficient cell growth and cellular homeostasis. While much is known about the transcriptional regulation of genes encoding transporters, less is understood about how transporter activity is modulated once the protein is functional in the membrane, a potentially more rapid and dynamic level of control. In this review, we bring together literature from the bacterial transport community exemplifying the extensive and diverse mechanisms that have evolved to rapidly modulate transporter function, predominantly by switching activity off. This includes small molecule feedback, inhibition by interaction with small peptides, regulation through binding larger signal transduction proteins and, finally, the emerging area of controlled proteolysis. Many of these examples have been discovered in the context of metal transport, which has to finely balance active accumulation of elements that are essential for growth but can also quickly become toxic if intracellular homeostasis is not tightly controlled. Consistent with this, these transporters appear to be regulated at multiple levels. Finally, we find common regulatory themes, most often through the fusion of additional regulatory domains to transporters, which suggest the potential for even more widespread regulation of transporter activity in biology.

Published
2023

46. Innovation and elaboration on the avian tree of life

Author

Guillerme, Thomas, Bright, Jen A, Cooney, Christopher R, Hughes, Emma C, Varley, Zoë K, Cooper, N, Beckerman, Andrew P, Thomas, Gavin H, Guillerme, Thomas, Bright, Jen A, Cooney, Christopher R, Hughes, Emma C, Varley, Zoë K, Cooper, N, Beckerman, Andrew P, and Thomas, Gavin H

Abstract

Widely documented, megaevolutionary jumps in phenotypic diversity continue to perplex researchers because it remains unclear whether these marked changes can emerge from microevolutionary processes. Here, we tackle this question using new approaches for modeling multivariate traits to evaluate the magnitude and distribution of elaboration and innovation in the evolution of bird beaks. We find that elaboration, evolution along the major axis of phenotypic change, is common at both macro- and megaevolutionary scales, whereas innovation, evolution away from the major axis of phenotypic change, is more prominent at megaevolutionary scales. The major axis of phenotypic change among species beak shapes at megaevolutionary scales is an emergent property of innovation across clades. Our analyses suggest that the reorientation of phenotypes via innovation is a ubiquitous route for divergence that can arise through gradual change alone, opening up further avenues for evolution to explore.

Published
2023

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