Biology subjects

Hayakawa, F.

Publications and source records attributed to Hayakawa, F..

3 recordsLinked to original sources

bioRxiv2026

Circadian Regulation of Taste Sensitivity in Human and Rat Active Periods

Most organisms exhibit endogenous 24-h rhythms that align physiology and behavior with the time of day; however, whether taste sensitivity oscillates in a circadian manner remains unclear, limiting our understanding of its role in feeding behavior. Here, we show that sensitivity to sweet and bitter tastes exhibits circadian modulation, peaking during the active period: daytime in humans and the dark phase in nocturnal rats. In humans, the rhythmicity of sweet taste was evident in detection but not recognition thresholds, indicating circadian modulation at the level of primary sensory processing rather than higher-order cognitive processes. In rats, increased sensitivity during the dark phase was accompanied by upregulation of taste-related genes in type II taste cells in tongue. These findings provide evidences that circadian regulation of taste sensitivity is conserved across species and appears to operate predominantly at the peripheral level. This mechanism may have evolved to optimize energy intake while minimizing exposure to dietary toxins, potentially contributing to survival and continuing to influence modern eating behavior through circadian-sensory-nutritional interactions.

physiology↗

bioRxiv2021

Periosteum-derived podoplanin-expressing stromal cells regulate nascent vascularization during epiphyseal marrow development

Bone marrow development and endochondral bone formation occur simultaneously. During endochondral ossification, periosteal vasculatures and stromal progenitors invade the primary avascular cartilaginous anlage; this induces primitive marrow development. We previously determined that bone marrow podoplanin (PDPN)-expressing stromal cells exist in a perivascular microenvironment, and promote megakaryopoiesis and erythropoiesis. In this study, we aimed to examine the involvement of PDPN-expressing stromal cells in the postnatal bone marrow generation. We found that periosteum-derived PDPN-expressing stromal cells regulate vascularization during postnatal epiphyseal marrow development. Our findings suggest that these cells act as pericytes on the primitive vasculature of the nascent marrow. They invade the cartilaginous epiphysis and regulate marrow development and homeostasis by maintaining vascular integrity. To the best of our knowledge, this is the first study to comprehensively examine how PDPN-expressing stromal cells contribute to marrow development and homeostasis.

developmental biology↗

bioRxiv2020

Elucidation of Japanese pepper (Zanthoxylum piperitum De Candolle) domestication using RAD-Seq

Japanese pepper, Zanthoxylum piperitum, is native to Japan and has four well-known lineages (Asakura, Takahara, Budou, and Arima), which are named after their production area or morphology. Restriction-site associated DNA sequencing (RAD-Seq) was used to analyse 93 accessions from various areas, including these four lineages. Single nucleotide variant analysis was used to classify the plants into eight groups: the Asakura and Arima lineages each had two groups, the Takahara and Budou lineages each had one group, and two additional groups were present. In one Asakura group and two Arima groups, the plants were present in agricultural fields and mountains, thus representing the early stage of domestication of the Japanese pepper. The second Asakura lineage group was closely related to plants present in various areas, and this represents the second stage of domestication of this plant because, after early domestication, genetically related lineages with desirable traits spread to the periphery. These results demonstrate that domestication of Japanese pepper is ongoing. In addition, this study shows that spineless plants are polyphyletic, despite the spineless lineage being considered a subspecies of Japanese pepper.

plant biology↗