Biology subjects

Bouchard, E.

Publications and source records attributed to Bouchard, E..

3 recordsLinked to original sources

bioRxiv2026

A crown story: How tree architecture drives maple syrup yields

Maple syrup production is strongly influenced by spring weather conditions, particularly the frequency and intensity of freeze-thaw cycles. However, marked individual differences in sap and sugar yields persist among trees growing under similar stand conditions, indicating additional tree-level sources of variation. This study aimed to explain inter-individual variability in maple yields in commercial high-vacuum syrup production using structural, morphological, and growth characteristics. We used terrestrial light detection and ranging to derive variables describing crown, stem, and whole-tree size, biomass, and structure in 38 mature sugar maples. We related these variables to individual yields, including sap volume, sugar content, and syrup production. Our models explained substantial inter-individual variability: 52% in sap sugar content, 44% in sap volume, and 47% in syrup production. Laterally expanded crowns were associated with higher sap sugar content, as were lower growth rates in the first 25 mm of wood. Sap volume was highest in large, heavily branched trees with crowns extending vertically along the stem. Projected crown surface area was the strongest predictor of syrup yield, with an estimated increase of 250 mL per 5.6 m2. These findings highlight the importance of multidimensional crown development in maximizing individual yields in maple syrup production.

ecology↗

bioRxiv2024

N-Acetylglucosamine Facilitates Coordinated Myoblast Flow, Forming the Foundation for Efficient Myogenesis

Skeletal muscle comprises 30-40% of a mammals body mass, maintaining its integrity through efficient muscle fiber regeneration, which involves myoblast differentiation into myotubes. Previously, we reported that N-acetylglucosamine (GlcNAc) promotes myogenesis in C2C12 cells, although the underlying mechanisms were unclear. UDP-GlcNAc, the activated form of GlcNAc, is critical for the biosynthesis of highly branched (N-acetyllactosamine-rich) N-linked oligosaccharides, which are recognized by galectin-3 (Gal-3), facilitating dynamic cell-cell and cell-matrix interactions. In this study, we used primary myoblasts from wild-type and Gal-3 null (Gal-3KO) mice, observing myotube formation through long-term live-cell imaging and single-cell tracking. We found that GlcNAc enhances myoblast fusion in a dose-dependent manner, and the addition of Gal-3 with GlcNAc leads to the formation of larger myotubes. Gal-3KO myoblasts exhibited a reduced capacity for myotube formation, a deficiency that was rectified by supplementing with GlcNAc and Gal-3. Our results highlight the critical role of Gal-3 interaction with oligosaccharides whose synthesis was promoted by GlcNAc in facilitating myotube formation. Single-cell tracking revealed that GlcNAc and Gal-3 increase myoblast motility, creating a faster-coordinated cell flow--a directed movement of myoblasts, along which myotubes form through cell fusion. Interestingly, myoblasts contributing to myotube formation were pre-positioned along the eventual shape of the myotubes before the establishment of the coordinated flow. These myoblasts moved along the flow, paused, and even moved against the flow, suggesting that both flow and initial positioning play roles in aligning myoblasts into the shape of a myotube. Overall, our findings demonstrate that GlcNAc, in conjunction with Gal-3, enhances myotube formation by fostering an environment conducive to myoblast positioning, establishing coordinated flow, and facilitating fusion. This suggests potential therapeutic applications of GlcNAc in muscle repair and muscle disorders.

cell biology↗

bioRxiv2021

Marker-free coselection for successive rounds of prime editing in human cells

Prime editing enables the introduction of precise point mutations, small insertions, or short deletions without requiring donor DNA templates. However, efficiency remains a key challenge in a broad range of human cell types. In this work, we designed a robust coselection strategy through coediting of the ubiquitous and essential sodium/potassium pump (Na+/K+ ATPase). We readily engineered highly modified pools of cells and clones with homozygous modifications for functional studies with minimal pegRNA optimization. This process revealed that nicking the non-edited strand stimulates multiallelic editing but often generates tandem duplications and large deletions at the target site, an outcome dictated by the relative orientation of the protospacer adjacent motifs. Our approach streamlines the production of cell lines with multiple genetic modifications to create cellular models for biological research and lays the foundation for the development of cell-type specific coselection strategies.

molecular biology↗