PLOS Biology: New Articles

1. Proteomic and phosphoproteomic analyses reveal that TORC1 is reactivated by pheromone signaling during sexual reproduction in fission yeast

   by Melvin Bérard, Laura Merlini, Sophie G. Martin

   Starvation, which is associated with inactivation of the growth-promoting TOR complex 1 (TORC1), is a strong environmental signal for cell differentiation. In the fission yeast Schizosaccharomyces pombe, nitrogen starvation has distinct physiological consequences depending on the presence of mating partners. In their absence, cells enter quiescence, and TORC1 inactivation prolongs their life. In presence of compatible mates, TORC1 inactivation is essential for sexual differentiation. Gametes engage in paracrine pheromone signaling, grow towards each other, fuse to form the diploid zygote, and form resistant, haploid spore progenies. To understand the signaling changes in the proteome and phospho-proteome during sexual reproduction, we developed cell synchronization strategies and present (phospho-)proteomic data sets that dissect pheromone from starvation signals over the sexual differentiation and cell–cell fusion processes. Unexpectedly, these data sets reveal phosphorylation of ribosomal protein S6 during sexual development, which we establish requires TORC1 activity. We demonstrate that TORC1 is re-activated by pheromone signaling, in a manner that does not require autophagy. Mutants with low TORC1 re-activation exhibit compromised mating and poorly viable spores. Thus, while inactivated to initiate the mating process, TORC1 is reactivated by pheromone signaling in starved cells to support sexual reproduction.
2. The representation of abstract goals in working memory is supported by task-congruent neural geometry

   by Mengya Zhang, Qing Yu

   Successful goal-directed behavior requires the maintenance and implementation of abstract task goals on concrete stimulus information in working memory. Previous working memory research has revealed distributed neural representations of task information across cortex. However, how the distributed task representations emerge and communicate with stimulus-specific information to implement flexible goal-directed computations is still unclear. Here, leveraging electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) in human participants along with state space analyses, we provided converging evidence in support of a low-dimensional neural geometry of goal information congruent with a designed task space, which first emerged in frontal cortex during goal maintenance and then transferred to posterior cortex through frontomedial-to-posterior theta coherence for implementation on stimulus-specific representations. Importantly, the fidelity of the goal geometry was associated with memory performance. Collectively, our findings suggest that abstract goals in working memory are represented in an organized, task-congruent neural geometry for communications from frontal to posterior cortex to enable computations necessary for goal-directed behaviors.
3. PLOS Biology and the life sciences in 2024

   by Daniel Routledge, on behalf of the PLOS Biology Staff Editors

   As we reach the end of 2024, we celebrate an amazing year of science for PLOS Biology and the life sciences more broadly, and thank everyone who continues to support the journal. As we reach the end of 2024, our Editorial celebrates an amazing year of science for PLOS Biology and the life sciences more broadly, and thanks everyone who supports the journal.
4. Lessons about physiological relevance learned from large-scale meta-analysis of co-expression networks in brain organoids

   by Yoshiaki Tanaka

   Integrative analysis of publicly available scRNA-seq data facilitates deeper understanding of biological phenomena with strong statistical power and high resolution. A new study in this issue of PLOS Biology examined the fidelity of various brain organoid protocols in reference to human primary developing brain by gene co-expression relationships with million-scale collection of public scRNA-seq data sets.
5. Maternal lipid mobilization is essential for embryonic development in the malaria vector <i>Anopheles gambiae</i>

   by Maurice A. Itoe, W. Robert Shaw, Iryna Stryapunina, Charles Vidoudez, Duo Peng, Esrah W. Du, Tasneem A. Rinvee, Naresh Singh, Yan Yan, Oleksandr Hulai, Kate E. Thornburg, Flaminia Catteruccia

   Lipid metabolism is an essential component in reproductive physiology. While lipid mobilization has been implicated in the growth of Plasmodium falciparum malaria parasites in their Anopheles vectors, the role of this process in the reproductive biology of these mosquitoes remains elusive. Here, we show that impairing lipolysis in Anopheles gambiae, the major malaria vectors, leads to embryonic lethality. Embryos derived from females in which we silenced the triglyceride lipase AgTL2 or the lipid storage droplet AgLSD1 develop normally during early embryogenesis but fail to hatch due to severely impaired metabolism. Embryonic lethality is efficiently recapitulated by exposing adult females to broad-spectrum lipase inhibitors prior to blood feeding, unveiling lipolysis as a potential target for inducing mosquito sterility. Our findings provide mechanistic insights into the importance of maternal lipid mobilization in embryonic health that may inform studies on human reproduction.