Search bioRxiv⌕ Search

Biology subjects

Matsumori, K.

Publications and source records attributed to Matsumori, K..

3 recordsLinked to original sources

Dihydroxyhexanoic acid biosynthesis controls turgor in pathogenic fungi

Many plant pathogenic fungi penetrate host surfaces mechanically, using turgor pressure generated by appressoria, specialized infection cells. These appressoria develop semipermeable cell walls and accumulate osmolytes internally to create turgor by osmosis. While melanin is known to be important for turgor generation, the mechanism for wall semipermeability has remained unclear. Here we identify PKS2 and PBG13, by reverse genetics, as crucial for forming the semipermeable barrier in anthracnose and rice blast fungi. These genes encode enzymes that synthesize 3,5-dihydroxyhexanoic acid polymers essential for the cell wall properties. Deleting these enzymes impairs cell wall porosity, abolishing turgor and pathogenicity without affecting melanization. Our findings uncover a novel mechanism of turgor generation, linking enzyme function to pathogen penetration and disease potential, presenting new targets for disease control.

plant biology↗

Interpersonal Comparison of Utility by Measuring Neural Activity

Aggregating well-being across individuals to reach collective decisions is one of the most fundamental problems in our society. Interpersonal comparisons of utility are pivotal and inevitable for well-being aggregation, because if utility is not interpersonally comparable, there is no rational aggregation procedure that simultaneously satisfies even mild conditions for validity (Arrows impossibility theorem); however, there are as yet no scientific methods for interpersonal comparison of utility. In this study, we developed a method based on brain signals. We found that the anterior cingulate and its adjacent ventromedial prefrontal activity is correlated with changes in expected utility. The ratio of lower- and higher-income participants neural signals coincided with estimates of their psychological pleasure by "impartial spectators." We confirmed the validity of our interpersonal utility comparison method using an independent large-scale dataset and used the aggregated well-being from our experimental data to derive an optimal decision rule. These findings suggest that our interpersonal comparison method enables scientifically reasonable well-being aggregation by escaping Arrows impossibility and has implications for the fair distribution of economic goods. Our method can be used for evidence-based policy-making in nations that use cost-benefit analyses or optimal taxation theory for policy evaluation.

neuroscience↗

Motivated for near impossibility: How task type and reward modulates intrinsic motivation and the striatal activation for an extremely difficult task.

Economic and decision-making theories suppose that people would disengage from a task with near zero success probability, because this implicates little normative utility values. However, humans are often motivated for an extremely challenging task, even without any extrinsic incentives. The current study aimed to address the nature of this challenge-based motivation and its neural correlates. We found that, when participants played a skill-based task without extrinsic incentives, their task enjoyment increased as the chance of success decreased, even if the task was almost impossible to achieve. However, such challenge-based motivation was not observed when participants were rewarded for the task or the reward was determined in a probabilistic manner. The activation in the ventral striatum/pallidum tracked the pattern of task enjoyment. These results suggest that people are intrinsically motivated to challenge a nearly impossible task, but only when the task requires certain skills and extrinsic rewards are unavailable.

neuroscience↗