Biology subjects

Tsuboi, M.

Publications and source records attributed to Tsuboi, M..

4 recordsLinked to original sources

bioRxiv2023

Mitochondrial protein FKBP8 captures PDZD8 to form mitochondria-ER contacts

Mitochondria-ER membrane contact sites (MERCS) represent a fundamental ultrastructural feature underlying unique biochemistry and physiology in eukaryotic cells. The ER protein PDZD8 is required for the formation of MERCS in many cell types, however, its tethering partner on the outer mitochondrial membrane (OMM) is currently unknown. Here we identified the OMM protein FKBP8 as the tethering partner of PDZD8 using a combination of unbiased proximity proteomics, CRISPR-Cas9 endogenous protein tagging, Cryo-Electron Microscopy (Cryo-EM) tomography, and correlative light-EM (CLEM). Single molecule tracking revealed highly dynamic diffusion properties of PDZD8 along the ER membrane with significant pauses and capture at MERCS. Overexpression of FKBP8 was sufficient to narrow the ER-OMM distance, whereas independent versus combined deletions of these two proteins demonstrated their interdependence for MERCS formation. Furthermore, PDZD8 enhances mitochondrial complexity in a FKBP8-dependent manner. Our results identify a novel ER-mitochondria tethering complex that regulates mitochondrial morphology in mammalian cells.

cell biology↗

bioRxiv2023

Developmental noise and phenotypic plasticity are correlated in Drosophila simulans

Non-genetic variation is the phenotypic variation induced by the differential expression of a genotype in response to varying environmental cues and is broadly categorized into two types: phenotypic plasticity and developmental noise. These variation aspects have been suggested to play an important role in adaptive evolution; however, the mechanisms by which these two types of non-genetic variations influence the evolutionary process are currently poorly understood. Using a machine-learning based phenotyping tool, we independently quantified the phenotypic plasticity and developmental noise in the wing morphological traits of a fruit fly Drosophila simulans. Utilizing a rearing experiment, we demonstrated plastic responses in both wing size and shape as well as non-zero heritability of both phenotypic plasticity and developmental noise, which suggests that adaptive phenotypic plasticity can evolve via genetic accommodation in the wing morphology of D. simulans. We found a positive correlation between phenotypic plasticity and developmental noise, while the correlation between the plastic response to three kinds of environmental factors that were examined (nutrient condition, temperature, and light-dark cycle) were poor. These results suggest that phenotypic plasticity and developmental noise contribute to evolvability in a similar manner, however, the mechanisms that underlie the correspondence between these two variation types remains to be elucidated. Lay SummaryNon-genetic variations consist of phenotypic plasticity and developmental noise, and these variations have been suggested to influence the direction and the rate of evolution. However, the role of phenotypic plasticity and developmental noise in evolutionary process is still poorly understood. Using a rearing experiment, we examined the heritability of plasticity and developmental noise, the correlation of the strength of plastic response to three kinds of environmental factors, and the relationship between plasticity and developmental noise in wing size and wing shape in Drosophila simulans. We found that the degree of phenotypic plasticity and developmental noise were heritable, and positively correlated with each other. Our results suggest that there two non-genetic variations dependently affect the direction and the rate of evolution together.

evolutionary biology↗

bioRxiv2023

Colonization of a novel host plant reduces phenotypic variation

Understanding the evolutionary potential of populations -evolvability- is key to predicting their ability to cope with novel environments. Despite growing evidence that evolvability determines the tempo and mode of adaptation, it remains unclear how adaptations to novel environments influence evolvability in turn. Here we address the interplay between adaptation and evolvability in the peacock fly Tephritis conura, which recently underwent an adaptive change in the length of female ovipositor following a host shift. By comparing evolvability in various morphological traits including female ovipositor length between ancestral and derived host races, we found that evolvability is decreased in females of the derived host race compared to the ancestral host race. We found a correlation between evolvability and divergence between populations in both sexes, indicating that the overall pattern of evolvability has not been disrupted by the host shift despite the reduction in females of the derived host race. Exploration of the pattern of phenotypic integration further revealed that the ovipositor length constitutes a module that is separated from other measured traits. These results suggest that adaptation to novel environments can affect evolvability, and that modularity helps minimizing detrimental effects that adaptations may cause to other correlated traits.

evolutionary biology↗

bioRxiv2022

Convergence and divergence of the adaptive landscape in two ecologically similar and sympatric damselfly species

Following the development of regression-based methods to estimate natural and sexual selection, evolutionary biologists have quantified the strength, mode and direction of selection in natural populations. Although this approach has been successful, its limitations include lack of replication across species, compromising the generality of the inferences beyond microevolutionary time scales. Here, we carried out a comparative study of selection on wing shape and body size across multiple populations of two closely related and ecologically similar pond damselflies: Enallagma cyathigerum and Ischnura elegans (Odonata: Coenagrionidae). We found weak stabilizing selection on wing shape in both sexes, and no evidence that selection on this trait differed between the species. In contrast, selection on body size was curvilinear in males and directional in females, and they differed in form (males) and intensity (females) between these two species. By analyzing selection on the fine-grained spatial scale, we found that selection on male body size was shaped by the local mating system, and the relationship between mating system characteristics and directional selection was remarkably consistent across these species. Finally, we present a graphical model that links contemporary selection and macroevolution. Based on this model, we conclude that the persistence in ecological modes of life in pond damselflies offers a plausible explanation for why varying selection in nature may still result in a stable adaptive zone lasting millions of years.

evolutionary biology↗