Biology subjects

Weaver, W.

Publications and source records attributed to Weaver, W..

2 recordsLinked to original sources

bioRxiv2025

Dominance of plasticity in wind-pollinated trees' flowering time response to temperature

Climate change is shifting the flowering phenology of wind-pollinated trees, leading to longer pollen seasons and heightened allergy risks. Accurately forecasting these phenological shifts requires a clear understanding of the underlying mechanisms and variations in the sensitivity of phenology to temperature. Here, we investigated the temperature sensitivity of flowering phenology in 74 wind-pollinated tree species across the US using long-term herbarium records spanning over a century. We found consistent phenological responses to spring temperature variations over space and over time in 77% of species, indicating that these long-lived trees can rely primarily on plasticity to cope with temperature variation across different regions. Sensitivity estimates were consistent across both century-scale and decadal time scales, challenging the previous understanding of declines. Interspecific variations in sensitivity exhibited a strong phylogenetic signal, indicating evolutionary conservatism in phenological responses among related species. Together, these findings shed light on the magnitude, mechanism, trend, and variability of temperature sensitivity of wind-pollinated tree flowering phenology. Our results improve the mechanistic basis for forecasting phenological shifts and their downstream effects on airborne pollen and allergen exposure under ongoing climate change.

ecology↗

bioRxiv2020

Activating an adaptive immune response from a hydrogel scaffold imparts regenerative wound healing.

Biomaterial scaffolds represent a promising approach for material-based tissue regeneration. We previously developed microporous annealed particle (MAP) hydrogels - a flowable, microparticle-based hydrogel in which neighboring hydrogel particles are linked in situ to form a porous scaffold that accelerates wound healing. To promote more extensive tissue ingrowth before scaffold degradation, we aimed to slow scaffold degradation by switching the chirality of the crosslinking peptides from L-peptides to D-peptides. Unexpectedly, despite showing the predicted slower enzymatic degradation in vitro, D-peptide crosslinked MAP hydrogel (D-MAP) hastened material degradation in vivo and imparted significant tissue regeneration to healed cutaneous wounds, including increased tensile strength and hair neogenesis. By themselves, D-chiral peptides were poor activators of macrophage innate immune signaling in vivo, but MAP particles elicit IL-33 type 2 myeloid cell recruitment which is amplified in vivo in the presence of D-peptides. Remarkably, D-MAP elicited significant antigen-specific immunity against the D-chiral peptides, and an intact adaptive immune system was required for the hydrogel-induced skin regeneration. These findings demonstrate that the generation of an adaptive immune response from a biomaterial is sufficient to induce cutaneous regenerative healing despite faster scaffold degradation.

bioengineering↗