Biology subjects

Jacobs, F. M. J.

Publications and source records attributed to Jacobs, F. M. J..

3 recordsLinked to original sources

bioRxiv2026

Single-cell transcriptomic atlas of frontoinsular cortex reveals molecular correlates of selective neuronal vulnerability in FTD

Frontotemporal dementia (FTD) is characterized by selective neuronal vulnerability, yet the features that predispose specific neuron types to degeneration remain unclear. We performed single-nucleus RNA sequencing of frontoinsular cortex, a region affected early in behavioral variant FTD, across individuals with C9orf72-associated and sporadic FTD-MND spectrum disease. By enriching for large projection neurons, we resolved molecular subtypes of layer 5 extratelencephalic neurons, including von Economo neurons, and identified selective depletion of specific layer 2/3 and layer 5 neuron subtypes, convergent across genotypes. Despite selective neuronal loss, disease-associated transcriptional changes were convergent across excitatory neuron populations, suggesting that they reflect upstream pathophysiology or shared responses to local neurodegeneration. By relating neighborhood-level depletion in disease to gene expression in controls, we found that baseline cellular respiration and ATP synthesis predict neuronal vulnerability in disease. These findings define molecular correlates of selective neuronal vulnerability in FTD and provide a framework linking cell type and state to neurodegeneration.

neuroscience↗

bioRxiv2025

Evolutionary hotspots of structural variation drive inter-individual differences in the expression of fusion transcripts in the human brain

While most protein-coding regions in our genome are highly conserved, phenotypic variation largely arises from differences in gene transcription, splicing, and translation. Intra-gene splicing variations are a known source of inter-individual differences. However, inter-gene splicing events, which generate fusion transcripts--RNA molecules combining exons from multiple distinct genes--are less explored. Fusion transcripts are well-studied in cancer, but their expression and inter-individual variability in normal human tissues has not been thoroughly investigated. We conducted a genome-wide fusion transcript analysis in postmortem human brain tissues from 276 individuals, identifying 717 distinct fusion transcripts. Many had protein coding potential, further supported in some cases by ribosome profiling data. Fusion transcripts that were present in only part of the human population were predominantly located within segmental duplication (SD) "hotspots"; highly copy number-variable genomic regions linked to neurodevelopmental and neurodegenerative diseases. None of these variable fusion transcripts were present in chimpanzee or rhesus macaque, suggesting they are human-specific. We confirmed that SD-derived fusion transcripts arise from structural genomic rearrangements in the human population, previously associated with neurodevelopmental and neurodegenerative disease risk. Inter-individual variation in fusion transcript expression represents an overlooked source of genetic diversity, with potential to contribute to differences in disease susceptibility.

molecular biology↗

bioRxiv2017

Structurally conserved primate lncRNAs are transiently expressed during human cortical differentiation and influence cell type specific genes

The cerebral cortex has expanded in size and complexity in primates, yet the underlying molecular mechanisms are obscure. We generated cortical organoids from human, chimpanzee, orangutan, and rhesus pluripotent stem cells and sequenced their transcriptomes at weekly time points for comparative analysis. We used transcript structure and expression conservation to discover thousands of expressed long non-coding RNAs (lncRNAs). Of 2,975 human, multi-exonic lncRNAs, 2,143 were structurally conserved to chimpanzee, 1,731 to orangutan, and 1,290 to rhesus. 386 human lncRNAs were transiently expressed (TrEx) and a similar expression pattern was often observed in great apes (46%) and rhesus (31%). Many TrEx lncRNAs were associated with neuroepithelium, radial glia, or Cajal-Retzius cells by single cell RNA-sequencing. 3/8 tested by ectopic expression showed [≥]2-fold effects on neural genes. This rich resource of primate expression data in early cortical development provides a framework for identifying new, potentially functional lncRNAs.

neuroscience↗