Biology subjects

Rosario, J. G.

Publications and source records attributed to Rosario, J. G..

3 recordsLinked to original sources

bioRxiv2026

Leaves in Transition: Single nuclei RNA sequencing provides insights into sorghums juvenile and adult phases

The transition from juvenile to adult phase (JA) is a key developmental process in plants, driven by conserved pathways that shape growth and stress responses. In monocots such as sorghum, this transition influences traits linked to environmental resilience, yet the regulation of micro-anatomical features such as trichomes and bulliform cells remains poorly understood. Here, we use single-nucleus RNA sequencing (snRNA-seq) to generate high-resolution gene expression maps of juvenile and adult sorghum leaves. Contrary to the traditional developmental model, we find that trichomes are present in both juvenile and adult leaves, with stage-dependent differences in gene expression. We also observe that bulliform cells, typically considered adult-specific, are present in juvenile leaves. At the transcriptomic level, cell populations cluster more strongly by developmental stage than by cell type, with juvenile cells grouping with other juvenile cells and adult cells with adult counterparts, indicating a dominant effect of developmental state on gene expression. In addition, we identify enrichment of dhurrin biosynthetic genes in trichome-associated cells as well as elevated expression of aquaporin genes in these cells, pointing to a potential role for trichomes in coordinating defense and water-related processes. Together, these findings refine current models of sorghum development and suggest that key epidermal cells and their associated functions may be established earlier than previously known. Collectively, this study provides a single nucleus resolved framework for understanding how developmental stage shapes gene expression in sorghum leaves.

plant biology↗

bioRxiv2026

Sub-cellular Systems Drift Drives Mosaic Evolution of Mammalian Neurons.

Evolution of the mammalian brain has been described as mosaic evolution wherein natural selection for behavioral function promotes independent evolution of specific functional units despite developmental constraints that might govern overall change1,2. Evidence of mosaic evolution has been reported at the level of gene expression in individual structures3, cell type abundances4, as well as gene regulatory changes at the single cell level5-7. In particular, it has been hypothesized that brain evolution involves changes in circuit organization6,8. Circuit-level changes involve sub-cellular compartments that mediate synaptic activity, raising the question whether mosaic brain evolution might be found at the sub-cellular scale. Here, we examine the rate of evolutionary divergence between Mus musculus (C57BL/6) and Rattus norvegicus (Sprague-Dawley) for their dendritic transcriptome, which shapes the post-synaptic proteome through sub-cellular localization and local translation9. We address the problem of variable assessment of the dendritic transcriptome by micro-dissecting individual hippocampal pyramidal neurons to create matched single cell libraries of the soma and the dendrites from the same cell and apply a machine learning model to predict localization. Our results show that the dendritic transcriptome is significantly more divergent than the soma, but the core functional roles of the dendritically localized genes are conserved. Examining gene families for their localization suggests enrichment of family level conservation or localization. We propose that the observed divergence may arise from a combination of adaptive modulation and system drift under selection for core function. Our study suggests fine-grained mosaic evolutionary dynamics at the scale of synaptic function that mediates information processing and neural connectivity.

evolutionary biology↗

bioRxiv2024

SCO-pH: Microfluidic dynamic phenotyping platform for high-throughput screening of single cell acidification

Studies on the dynamics of single cell phenotyping have been hampered by the lack of quantitative high-throughput metabolism assays. Extracellular acidification, a prominent phenotype, yields significant insights into cellular metabolism, including tumorigenicity. Here, we develop a versatile microfluidic system for single cell optical pH analysis (SCO-pH), which compartmentalizes single cells in 140-pL droplets and immobilizes approximately 40,000 droplets in a two-dimensional array for temporal extracellular pH analysis. SCO-pH distinguishes cells undergoing hyperglycolysis induced by oligomycin A from untreated cells by monitoring their extracellular acidification. To facilitate pH sensing in each droplet, we encapsulate a cell-impermeable pH probe whose fluorescence intensities are quantified. Using this approach, we can differentiate hyperglycolytic cells and concurrently observe single cell heterogeneity in extracellular acidification dynamics. This high-throughput system will be useful in applications that require dynamic phenotyping of single cells with significant heterogeneity.

bioengineering↗