Biology subjects

Snyder, W. E.

Publications and source records attributed to Snyder, W. E..

4 recordsLinked to original sources

bioRxiv2026

Higher Lipid Saturation in Well-Irrigated Georgia Cotton Plants: A Field-Based NMR Metabolomics Study

Cotton (Gossypium hirsutum) is an economically important crop, but it faces increasing pest outbreaks, especially in non-irrigated areas. In this study, 20 cotton farms using center-pivot irrigation were sampled in southern Georgia to assess chemical differences between non-irrigated and irrigated areas. Proton (1H) nuclear magnetic resonance (NMR) data were obtained from cotton leaves, and Principal Component Analysis (PCA) was performed to assess differences in chemical composition. Across all samples, farm site accounted for most of the variability, but within each farm site, the PCA scores plots showed clear separation between non-irrigated and irrigated conditions in 10 sites. Inspecting the PCA loadings revealed significant resonances resembling a lipid-like signal. After reverse-phase fractionation, we observed that many of these resonances appeared together in later fractions, suggesting a lipid, specifically a fatty acid such as linoleic acid. We hypothesized that differences in net lipid saturation level may drive separation between non-irrigated and irrigated samples. Six farm sites had a significantly or marginally significantly higher degree of unsaturation in irrigated samples, while one farm site had significantly higher unsaturation in non-irrigated samples. Our results indicate that drought stress likely affects lipid profile composition, which could be driving higher herbivorous pest densities in drought-stressed crops.

plant biology↗

bioRxiv2026

Genetic insights on the mechanisms of human cortical folding

The unique and intricate pattern of human cortical folding is rooted in fetal neurodevelopmental processes and can now be comprehensively quantified by new neuroimaging-derived measures of sulcal complexity. Here, we provide the first genetic maps of human sulcal complexity. Beginning with large effects of rare variants, we survey nine different neurogenetic syndromes (n=615), detecting visible changes in sulcal complexity on a shared axis of sulcal change coupled to the prenatal timing of sulcation. Turning to common genetic variants, we use genome-wide association studies of complexity scores for 40 sulci in the UK Biobank (n[~]29,000) to (i) resolve variable heritability across sulci, (ii) reveal both local and remote shared genetic effects with cortical morphology, and (iii) identify complexity-associated genes and their embedding in brain maps of prenatal gene expression. These reference genetic maps uncover multiple new mechanistic pathways for cortical morphogenesis in health and disease.

neuroscience↗

bioRxiv2023

A bipolar taxonomy of adult human brain sulcal morphology related to timing of fetalsulcation and trans-sulcal gene expression gradients

We developed a computational pipeline (now provided as a resource) for measuring morphological similarity between cortical surface sulci to construct a sulcal phenotype network (SPN) from each magnetic resonance imaging (MRI) scan in an adult cohort (N=34,725; 45-82 years). Networks estimated from pairwise similarities of 40 sulci on 5 morphological metrics comprised two clusters of sulci, represented also by the bipolar distribution of sulci on a linear-to-complex dimension. Linear sulci were more heritable and typically located in unimodal cortex; complex sulci were less heritable and typically located in heteromodal cortex. Aligning these results with an independent fetal brain MRI cohort (N=228; 21-36 gestational weeks), we found that linear sulci formed earlier, and the earliest and latest-forming sulci had the least between-adult variation. Using high-resolution maps of cortical gene expression, we found that linear sulcation is mechanistically underpinned by trans-sulcal gene expression gradients enriched for developmental processes.

neuroscience↗

bioRxiv2021

No broad decline of breeding monarch butterflies in North America: implications for conservation efforts

Many insects are in clear decline, with monarch butterflies (Danaus plexippus) drawing particular attention as a flagship species. Falling numbers of overwintering monarchs are well documented, but there has been debate regarding population trends of summer breeding populations. Here, we compile a series of long-term monarch monitoring datasets, some which are analyzed here for the first time, that reveal highly variable responses across the migratory geographic range, but no broad net decline in numbers of breeding monarchs. We also did not find evidence that sampling biased towards natural sites was masking declines at disturbed sites. Overall, our results suggest a robust resiliency in summer populations that thus far has allowed recovery from losses during the winter. Thus, monarchs may not require as much breeding habitat restoration as once thought, and focus should be on conserving the fall and spring migration.

ecology↗