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Biology subjects

Reich, H.

Publications and source records attributed to Reich, H..

3 recordsLinked to original sources

Molecular and phenotypic footprints of climate in native Arabidopsis thaliana

Climate change poses a major threat to humanity by driving biodiversity loss and reducing crop yields1,2. To understand the molecular and developmental impacts of rising temperatures, plant science has relied heavily on the model organism Arabidopsis thaliana. Despite decades of research, its development under fully natural conditions remains poorly understood, and only [~]30% of genes have experimental functional annotations, largely because many functions are subtle or manifest only in specific laboratory or ecological contexts3. Here, we address this gap with a landscape transcriptomic approach that integrates intensive phenotyping and transcriptomic profiling of naturally occurring plants in their native habitats4. Across two contrasting field sites and five growing seasons (2021-2025), we phenotyped more than 3,000 A. thaliana plants and generated >1,600 matching transcriptomes. The resulting >30,000 quantitative trait measurements provide a unique opportunity to link climate fluctuations with plant traits and gene expression. Seasons characterized by extreme temperature anomalies directly influenced plant traits, and climatic variables together explained up to 17% of phenotypic variation. In situ transcriptomes carried clear temperature and local environmental signatures, closely matching temperature-response programs known from the laboratory. Leveraging paired per-plant transcriptomes and phenotypes, we applied machine learning to predict regulators of climate-relevant and other plant traits under natural conditions. The models recovered canonical thermomorphogenesis regulators, including PHYTOCHROME INTERACTING FACTOR 4 (PIF4)5,6, providing ecological evidence that temperature signaling pathways defined in controlled environments operate in the wild, and expanded this regulatory landscape by identifying hormonal receptors, signaling components, and previously uncharacterized genes, some of which we functionally validated. Together, this work demonstrates that landscape transcriptomics, by integrating natural field transcriptomes with phenotypes, and thus, capturing environmental and regulatory states, enables the predictive identification of genetic regulators of temperature responses and broader plant traits. This makes landscape transcriptomics a scalable framework for climate-aware functional genomics in plants.

plant biology↗

Endocrine-enriched stem cell-derived islets improve long-term safety in vivo

Fully differentiated stem cell-derived islets (SC-islets) are proven to normalise blood glucose in type 1 diabetic patients. However, the presence of off-target cell types and the immature SC-islet function upon transplantation remain unresolved problems. Here, we established sorting strategies to generate SC-islets with defined glucagon-producing SC-- and insulin-producing {beta}-cell ratios and assessed their safety and efficacy in vitro and in vivo. Engineering SC-islets is beneficial to the insulin response in vitro, which does not translate to improved glycaemic regulation in vivo. Importantly, hormone-producing endocrine cell enrichment and thus off-target cell type depletion eliminated the risk for unwanted outgrowth in vivo. Single cell analysis defined off-target cells in vitro and in vivo and identified marker genes to assess SC-islet quality and define safety release criteria before graft transplantation. This study highlights the importance of determining the SC-islet composition and establishing rigorous quality controls to ensure long-term safety for {beta}-cell replacement therapy.

bioengineering↗

Genetic architecture and evolution of color variation in American black bears

Color variation is a frequent evolutionary substrate for camouflage in small mammals but the underlying genetics and evolutionary forces that drive color variation in natural populations of large mammals are mostly unexplained. The American black bear, Ursus americanus, exhibits a range of colors including the cinnamon morph which has a similar color to the brown bear, U. arctos, and is found at high frequency in the American southwest. Reflectance and chemical melanin measurements showed little distinction between U. arctos and cinnamon U. americanus individuals. We used a genome-wide association for hair color as a quantitative trait in 151 U. americanus individuals and identified a single major locus (P < 10-13). Additional genomic and functional studies identified a missense alteration (R153C) in Tyrosinase-related protein 1 (TYRP1) that impaired protein localization and decreased pigment production. Population genetic analyses and demographic modeling indicated that the R153C variant arose 9.36kya in a southwestern population where it likely provided a selective advantage, spreading both northwards and eastwards by gene flow. A different TYRP1 allele, R114C, contributes to the characteristic brown color of U. arctos, but is not fixed across the range. HIGHLIGHTSO_LIThe cinnamon morph of American black bears and brown bears have different missense mutations in TYRP1 that account for their similar coloration C_LIO_LITYRP1 variants in American black bears and brown bears are loss-of-function alleles associated with impaired protein localization to melanosomes C_LIO_LIIn American black bears, the variant causing the cinnamon morph arose 9,360 years ago in the western lineage where it provides an adaptive advantage, and has spread northwards and eastwards by migration C_LI

evolutionary biology↗