Study Maps Genetic and Environmental Influences on Brain DNA Methylation in Black Americans
Researchers analyzed DNA methylation patterns in postmortem brain tissue from 168 Black American adults to understand how genetic variation and environmental factors shape the brain's epigenome. The study found that genetically-influenced methylation is concentrated in repressive, repeat-rich regions of DNA, while environmentally-associated changes occur more in gene-proximal areas. These findings could help explain epigenomic mechanisms underlying neuropsychiatric and neurodegenerative diseases.
A new study published on bioRxiv examined whole-genome bisulfite sequencing data from 168 admixed Black American adults in the BrainSEQ consortium to map how inherited genetic variation and cumulative environmental experience shape DNA methylation in the brain. Researchers developed and validated an SNP-based elastic-net modeling approach to classify variably methylated regions (VMRs) by their genetic versus environmental contributions, addressing limitations of conventional methods in postmortem cohorts with modest sample sizes. They identified 31,143 VMRs and found that genetically-anchored methylation is enriched in distal intergenic sequences with repressive chromatin states and repeat elements, while environmentally-associated methylation is more concentrated near genes and active regulatory elements. The study also revealed that metadata-associated VMRs showed region-, exposure-, and donor-group-dependent patterns, including associations with substance use and sociodemographic variables. By clarifying this architecture in an underrepresented population, the work provides insights into how inherited variation structures the brain methylome and may inform understanding of neuropsychiatric and neurodegenerative disease mechanisms.
Limitations & open questions
The study's own limitations include modest sample size (168 donors) and reliance on postmortem tissue, which may not fully capture dynamic methylation changes in living brains. The generalizability of findings to other ancestral populations beyond the Black American and non-Hispanic white American cohorts examined remains to be determined.
What different sources said
- bioRxivCenter
Local SNP-explained methylation variation reveals genetically anchored and exposure-associated methylation architecture in the human brain
Related
CoTAL: New Method Uses AI and Teacher Feedback to Improve Student Assessment Scoring Across Subjects
Researchers introduced CoTAL, a system combining large language models with human feedback to automatically score student work and provide explanations. The approach uses chain-of-thought prompting and iterative refinement guided by teachers and students to improve accuracy. The method showed significant performance gains and could help educators scale formative assessment across science, computing, and engineering domains.
Social Media Data as a Research Tool for Understanding COVID-19 Information Spread and Public Perception
A research paper examines how social media platforms have become major sources of COVID-19 information and explores methods for analyzing linguistic, visual, and emotional indicators in user posts during the pandemic. With 4.6 billion social media users worldwide, the volume and nature of information shared on these platforms significantly influences public perception and coping mechanisms. The study is relevant because it demonstrates how machine learning and natural language processing can extract insights from social media data to improve public health communication and identify misinformation.
Researchers Develop Fact-Checking System to Reduce Hallucinations in Healthcare AI Models
Researchers have created a fact-checking module paired with a domain-specific language model designed to reduce hallucinations in healthcare AI systems. The system uses granular logical checks against electronic health records to validate medical information generated by large language models. This approach is significant because accurate, reliable AI outputs are critical for patient safety and medical decision-making.