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PLOS Biology: New Articles

  • Autophagy-related protein Atg11 is essential for microtubule-mediated chromosome segregation

    by Md. Hashim Reza, Rashi Aggarwal, Jigyasa Verma, Nitesh Kumar Podh, Ratul Chowdhury, Gunjan Mehta, Ravi Manjithaya, Kaustuv Sanyal

    Emerging studies hint at the roles of autophagy-related proteins in various cellular processes. To understand if autophagy-related proteins influence genome stability, we sought to examine a cohort of 35 autophagy mutants in Saccharomyces cerevisiae. We observe cells lacking Atg11 show poor mitotic stability of minichromosomes. Single-molecule tracking assays and live cell microscopy reveal that Atg11 molecules dynamically localize to the spindle pole bodies (SPBs) in a microtubule (MT)-dependent manner. Loss of Atg11 leads to a delayed cell cycle progression. Such cells accumulate at metaphase at an elevated temperature that is relieved when the spindle assembly checkpoint (SAC) is inactivated. Indeed, atg11∆ cells have stabilized securin levels, that prevent anaphase onset. Ipl1-mediated activation of SAC also confirms that atg11∆ mutants are defective in chromosome biorientation. Atg11 functions in the Kar9-dependent spindle positioning pathway. Stabilized Clb4 levels in atg11∆ cells suggest that Atg11 maintains Kar9 asymmetry by facilitating proper dynamic instability of astral microtubules (aMTs). Loss of Spc72 asymmetry contributes to non-random SPB inheritance in atg11∆ cells. Overall, this study uncovers an essential non-canonical role of Atg11 in the MT-mediated process of chromosome segregation.

  • A single enzyme becomes a Swiss Army knife

    by Andreas Sichert

    An alga that abandoned photosynthesis? This Primer explores a PLOS Biology study showing that a single horizontal gene transfer event allowed the diatom Nitzschia sing1 to evolve a complete enzymatic machinery to break down alginate from brown algae, unlocking a new ecological niche.

  • Social knowledge about others is anchored to self-knowledge in the hippocampal formation

    by Marta Rodríguez Aramendía, Mariachiara Esposito, Raphael Kaplan

    Mounting evidence suggests the human hippocampal formation (HF) maps how different people’s attributes relate to each other. Yet, it’s unclear if hippocampal map-like knowledge representations of other people are shaped by self-knowledge. Here, we test if a prominent heuristic involving an implicit reliance on self-knowledge when rating others, egocentric anchoring-and-adjustment, is present in the HF when relational information about different social entities is retrieved. Participants first provided likelihood ratings of partaking in everyday activities for themselves, fictitious individuals, and familiar social groups. During a neuroimaging task that doesn’t require using self-knowledge, participants then learned a stranger’s preference for an activity relative to one of the fictitious individuals and inferred how the stranger’s preference related to the groups’ preferences. Isolating the neural representation of egocentric anchoring when retrieving relational social knowledge, the HF and dorsomedial prefrontal cortex (dmPFC) represented group entities’ preferences relative to the self. Furthermore, the HF selectively represented group identity over other learned entities, confirming the HF was primarily engaged by social comparisons in the more ample map-like reference frame. Taken together, these results imply that self-knowledge implicitly influences how the HF learns about others.

  • Ploidy plasticity drives fungal resistance to azoles used in agriculture and clinics

    by Kaustuv Sanyal, Aswathy Narayanan

    The rapid growth in antimicrobial resistance is of great medical concern. A new study in PLOS Biology unveils the link between ploidy plasticity and the emergence of antifungal resistance in Candida tropicalis. The rapid growth in antimicrobial resistance is of great medical concern. This Primer highlights a new study in PLOS Biology that unveils the link between ploidy plasticity and the emergence of antifungal resistance in Candida tropicalis.

  • A hypermobile prophage in the genome of a key human gut bacterium

    by Andrey N. Shkoporov, Colin Hill

    Phages infecting anaerobic bacteria are highly abundant in the mammalian gut, but their biology and ecological impact are poorly understood. A new PLOS Biology study provides a glimpse into the disruptive biology of the Hankyphages, parasites of the ubiquitous Bacteroidaceae.