@article{lau_nie_ross_endersby-harshman_hoffmann_2024, title={Long-term impacts of egg quiescence and<i> Wolbachia</i> infection on lipid profiles in<i> Aedes aegypti</i> : Ovarian roles in lipid synthesis during reproduction}, volume={157}, ISSN={["1879-1611"]}, DOI={10.1016/j.jinsphys.2024.104674}, abstractNote={Wolbachia, an endosymbiotic bacterium, relies on nutrients from its host to complete its life cycle. The presence of Wolbachia strain wAlbB in the mosquito Aedes aegypti during egg or larval stages affects the host's development, leading to the absence of developed and visible ovaries in adult mosquito females. In this study, we investigated the impacts of egg quiescence and Wolbachia infection on lipid profiles of adult Ae. aegypti females, and discerned the role of ovaries in lipid synthesis in the reproductive process. The lipidomes of Wolbachia infected and uninfected female individuals at various developmental stages were quantitatively analyzed by LC-MS/MS. Lipidomic change patterns were systematically further investigated in wAlbB-infected fertile females and infertile females following blood feeding. Prolonged egg quiescence induced a shortage of acyl-carnitine (CAR) and potentially impacted some molecules of diacyl-phospholipid (diacyl-PL) and sphingolipid (SL) in young adult mosquitoes. After the first gonotrophic cycle, infertile females accumulated more CAR and lyso-phospholipid (lyso-PL) than fertile females. Then in the second gonotrophic cycle, the patterns of different lipid groups remained similar between fertile and infertile females. Only a small proportion of molecules of triglyceride (TG), phospholipid (lyso-PL and diacyl-PL) and ceramide (Cer) increased exclusively in fertile females from 0 h to 16 h post blood meal, suggesting that the generation or prescence of these lipids rely on ovaries. In addition, we found cardiolipins (CL) might be impacted by Wolbachia infection at the egg stage, and infected mosquitoes also showed distinct patterns between fertile and infertile females at their second gonotrophic cycle. Our study provides new insights into the long-term influence of Wolbachia on lipid profiles throughout various life stages of mosquitoes. Additionally, it suggests a role played by ovaries in lipid synthesis during mosquito reproduction.}, journal={JOURNAL OF INSECT PHYSIOLOGY}, author={Lau, Meng-Jia and Nie, Shuai and Ross, Perran A. and Endersby-Harshman, Nancy M. and Hoffmann, Ary A.}, year={2024}, month={Sep} }
 @article{hopkins_lopezguerra_lau_raymann_2024, title={Making a Pathogen? Evaluating the Impact of Protist Predation on the Evolution of Virulence in Serratia marcescens}, volume={16}, ISSN={["1759-6653"]}, DOI={10.1093/gbe/evae149}, abstractNote={Abstract Opportunistic pathogens are environmental microbes that are generally harmless and only occasionally cause disease. Unlike obligate pathogens, the growth and survival of opportunistic pathogens does not rely on host infection or transmission. Their versatile lifestyles make it challenging to decipher how and why virulence has evolved in opportunistic pathogens. The Coincidental Evolution Hypothesis (CEH) postulates that virulence results from exaptation or pleiotropy, i.e., traits evolved for adaptation to living in one environment that have a different function in another. In particular, adaptation to avoid or survive protist predation has been suggested to contribute to the evolution of bacterial virulence (the training grounds hypothesis). Here we used experimental evolution to determine how the selective pressure imposed by a protist predator impacts the virulence and fitness of a ubiquitous environmental opportunistic bacterial pathogen that has acquired multi-drug resistance: Serratia marcescens. To this aim, we evolved S. marcescens in the presence or absence of generalist protist predator, Tetrahymena thermophila. After 60 days of evolution, we evaluated genotypic and phenotypic changes by comparing evolved S. marcescens to the ancestral strain. Whole genome shotgun (WGS) sequencing of the entire evolved populations and individual isolates revealed numerous cases of parallel evolution, many more than statistically expected by chance, in genes associated with virulence. Our phenotypic assays suggested that evolution in the presence of a predator maintained virulence, whereas evolution in the absence of a predator resulted in attenuated virulence. We also found a significant correlation between virulence, biofilm formation, growth, and grazing resistance. Overall, our results provide evidence that bacterial virulence and virulence related traits are maintained by selective pressures imposed by protist predation.}, number={8}, journal={GENOME BIOLOGY AND EVOLUTION}, author={Hopkins, Heather A. and Lopezguerra, Christian and Lau, Meng-Jia and Raymann, Kasie}, year={2024}, month={Aug} }