Review
Entomology
Christoph Vorburger
Summary: Insect host-parasitoid interactions are common in nature and characterized by host specialization. Many host species rely on heritable bacterial endosymbionts for defense against parasitoids. These symbionts provide strong and specific resistance, potentially due to variation in symbiont-produced toxins. Defensive symbionts are thus important for diversifying selection and may alter host-parasitoid food web structures. Additionally, other defensive mutualisms may also exert diversifying selection on insect parasitoids.
ANNUAL REVIEW OF ENTOMOLOGY
(2022)
Letter
Evolutionary Biology
Cameron A. Smith, Ben Ashby
Summary: Defensive symbionts in the host microbiome can provide protection from infection or reduce the harms of being infected. However, the consequences of introducing a defensive symbiont for parasite evolution and how the symbiont may coevolve with the parasite have been relatively understudied.
Article
Genetics & Heredity
Helen Rebecca Davison, Gregory D. D. Hurst, Stefanos Siozios
Summary: We explore the diversity of the genus 'Candidatus Megaira' using Sequence Read Archive and metagenomic assemblies. We identify four 'Ca. Megaira' genomes, including one complete scaffold, and an additional 14 draft genomes from uncategorized environmental metagenome-assembled genomes. Our findings reveal the underestimation of the diversity of 'Ca. Megaira' and suggest a potential for defensive symbiosis in this genus.
MICROBIAL GENOMICS
(2023)
Article
Chemistry, Organic
Munhyung Bae, Emily Mevers, Gleb Pishchany, Sarah G. Whaley, Charles O. Rock, David R. Andes, Cameron R. Currie, Monica T. Pupo, Jon Clardy
Summary: This report presents the molecular exchange between multilateral symbiosis partners, resulting in the characterization of two new metabolites, which disrupt fatty acid biosynthesis by selectively inhibiting FabH.
Article
Ecology
Elena Gimmi, Christoph Vorburger
Summary: The genetic interactions between hosts and parasites play a significant role in determining the dynamics of coevolution. In the case of the black bean aphid and its parasitoid, the specificity of resistance conferred by a heritable bacterial endosymbiont is crucial in maintaining genetic variation and mediating coevolutionary processes.
JOURNAL OF EVOLUTIONARY BIOLOGY
(2021)
Article
Biochemistry & Molecular Biology
Gilbert Smith, Alejandro Manzano-Marin, Mariana Reyes-Prieto, Catia Sofia Ribeiro Antunes, Victoria Ashworth, Obed Nanjul Goselle, Abdulhalem Abdulsamad A. Jan, Andres Moya, Amparo Latorre, M. Alejandra Perotti, Henk R. Braig
Summary: We propose that Demodex folliculorum represents a transitional stage from a host-injuring obligate parasite to an obligate symbiont. Genome sequencing revealed extensive genome reduction and a decrease in the number of cells in the mite. This is the first evolutionary step in adopting a reductive, parasitic, or endosymbiotic lifestyle in an arthropod species.
MOLECULAR BIOLOGY AND EVOLUTION
(2022)
Article
Computer Science, Artificial Intelligence
Wenbin Li, Lei Wang, Xingxing Zhang, Lei Qi, Jing Huo, Yang Gao, Jiebo Luo
Summary: This article investigates defensive few-shot learning, a challenging problem in learning robust few-shot models against adversarial attacks. Existing adversarial defense methods cannot effectively solve this problem due to the inconsistency in sample-level distribution between training and test sets in few-shot learning. To overcome this, the authors propose a general defensive few-shot learning framework that addresses two key questions: how to transfer adversarial defense knowledge across different sample distributions, and how to narrow the distribution gap between clean and adversarial examples in few-shot setting. Experimental results show that the proposed framework effectively enhances robustness of existing few-shot models against adversarial attacks. Code is available at https://github.com/WenbinLee/DefensiveFSL.git.
IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE
(2023)
Article
Entomology
Alessia Cappelli, Dezemona Petrelli, Giuliano Gasperi, Aurelio Giuseppe Maria Serrao, Irene Ricci, Claudia Damiani, Guido Favia
Summary: The Mediterranean fly (Medfly) is a highly destructive fruit pest that causes significant economic damages. Current pest management strategies heavily rely on insecticides, which raise environmental concerns. Therefore, exploring the Medfly microbiota and developing microbial symbionts as tools for pest control is gaining importance.
Article
Plant Sciences
Bailey W. Miller, Eric W. Schmidt, Gisela P. Concepcion, Margo G. Haygood
Summary: Bacteria use small molecules to regulate the acquisition, uptake, and sequestration of transition metal ions. They scavenge low-abundance nutrient metals with high-affinity chelating molecules called siderophores, while sequestering and detoxifying toxic metal ions. Bacteria often produce a variety of compounds that bind different metal ions at different affinities to maintain homeostasis.
JOURNAL OF NATURAL PRODUCTS
(2022)
Article
Multidisciplinary Sciences
Daniel Jercog, Nanci Winke, Kibong Sung, Mario Martin Fernandez, Claire Francioni, Domitille Rajot, Julien Courtin, Fabrice Chaudun, Pablo E. Jercog, Stephane Valerio, Cyril Herry
Summary: The study found that threat representations and avoidance behavior initiation are dynamically encoded in the overall population activity of dmPFC neurons in mice. While dmPFC population activity at stimulus onset encodes sustained threat representations driven by the amygdala, it does not predict action outcome. Transient dmPFC population activity before the initiation of action reliably predicts avoided from non-avoided trials, revealing the dynamic process of information linking threats with defensive actions within prefrontal networks.
Article
Ecology
Zachary Emberts, John J. Wiens
Summary: In intraspecific fights among animals, reducing damage plays a crucial role in determining the contest winner. This study found that enhancing an individual's defensive armour increased their likelihood of winning a fight, demonstrating the impact of damage and damage-reducing structures on fighting success. These results support the fundamental assumption in theoretical fighting models that damage is a cost that can influence contest outcomes.
FUNCTIONAL ECOLOGY
(2021)
Article
Neurosciences
Cyril Herry, Daniel Jercog
Summary: Previous studies focused on individual cells' contribution to threat-related behavior, but recent developments have allowed us to understand how collective neuronal activity supports such behavior.
CURRENT OPINION IN NEUROBIOLOGY
(2022)
Article
Microbiology
Shigeyuki Kakizawa, Takahiro Hosokawa, Kohei Oguchi, Kaori Miyakoshi, Takema Fukatsu
Summary: Many insects have facultative symbiotic bacteria, and the prevalence of infection provides important information about the biological impact of these microbial associates. In this study, diverse stinkbugs were surveyed for Spiroplasma infection, revealing a low infection prevalence. Molecular analysis showed that stinkbug-associated Spiroplasma symbionts have multiple evolutionary origins and are not co-speciated with the host stinkbugs. There is a potential for host-symbiont specificity and/or ecological symbiont sharing. Spiroplasma symbionts are generally less abundant than primary gut symbiotic bacteria, localized to various tissues and organs, and vertically transmitted to offspring. They are facultative bacterial associates and not essential for the host stinkbugs, similar to Spiroplasma symbionts of fruit flies and aphids.
FRONTIERS IN MICROBIOLOGY
(2022)
Article
Multidisciplinary Sciences
Joerg Wiedenmann, Cecilia D'Angelo, M. Loreto Mardones, Shona Moore, Cassandra E. Benkwitt, Nicholas A. J. Graham, Bastian Hambach, Paul A. Wilson, James Vanstone, Gal Eyal, Or Ben-Zvi, Yossi Loya, Amatzia Genin
Summary: Research shows that corals acquire dissolved inorganic nitrogen and phosphorus by feeding on symbiont cells, which are essential nutrients for their success in nutrient-poor waters.
Article
Multidisciplinary Sciences
Sungwhan F. Oh, T. Praveena, Heebum Song, Ji-Sun Yoo, Da-Jung Jung, Deniz Erturk-Hasdemir, Yoon Soo Hwang, ChangWon C. Lee, Jerome Le Nours, Hyunsoo Kim, Jesang Lee, Richard S. Blumberg, Jamie Rossjohn, Seung Bum Park, Dennis L. Kasper
Summary: The study revealed that immunomodulatory alpha-galactosylceramides from the human symbiont Bacteroides fragilis have structure-specific immunomodulatory activity, which is related to the regulation of NKT cells, can interact with CD1d antigen presentation molecules to bind with the receptor on NKT cells. These findings demonstrate a structural and molecular-level paradigm of immunomodulatory control by interactions of endobiotic metabolites with diet, microbiota, and the immune system.