2025-11-25 九州大学
図 ブナ科樹木4種の比較分子フェノロジー(a:対象としたブナ科4種の系統関係。伊都キャンパスを含む九州北部に生育する個体をモニタリングに用いた。 b:分子フェノロジーの比較から明らかにされた季節によって異なる遺伝子発現パターンの多様性。冬季に有意な低下が見られ、冬に発現する遺伝子は多様化しづらいことを示唆する。)
<関連情報>
- https://www.kyushu-u.ac.jp/ja/researches/view/1358
- https://www.kyushu-u.ac.jp/f/63932/25_1125_01.pdf
- https://elifesciences.org/articles/107309
季節環境における遺伝子発現の進化 Evolution of gene expression in seasonal environments
Shuichi N Kudo,Yuka Ikezaki,Junko Kusumi,Hideki Hirakawa,Sachiko Isobe,Akiko Satake
eLife Published:Nov 25, 2025
DOI:https://doi.org/10.7554/eLife.107309.3
Abstract
The biological activities of organisms are closely linked to seasonality. Phenology, the temporal orchestration of biological activities, is governed by gene expression, yet the evolutionary dynamics underlying seasonal gene expression remain unclear. To investigate these dynamics, we compared genome-wide expression dynamics (molecular phenology) in four dominant evergreen Fagaceae species in Asia (Quercus glauca, Q. acuta, Lithocarpus edulis, and L. glaber), using leaf and bud tissues over two seasonal cycles. We assembled high-quality reference genomes, identifying 11749 single-copy orthologous genes. Seasonal transcriptomic profiling of these orthologous genes revealed highly conserved gene expression across species in winter when temperatures fall below ~10 °C. Rhythmic gene expression with significant periodic oscillations was more prevalent in buds (51.9%) than in leaves (40.6%), with most rhythmic genes (78.4–92.0%) exhibiting annual periodicity, while a smaller fraction (1.2–11.9%) followed half-annual cycles. The seasonal peaks of rhythmic genes were highly synchronized across species in winter but diverged during the growing season, reflecting species-specific timing of leaf flushing and flowering. These findings suggest that the four species share a common molecular calendar in winter, which constrains the evolution of gene expression under seasonal environments.
