Uploaded January 2026 | Updated September 2026, 9 hours ago
Discover how Fiber-seq reveals 50,000+ regulatory elements invisible to traditional chromatin accessibility methods. In this presentation from PAG 2026, Christine Queitsch, PhD shares findings that double our understanding of maize gene regulation.
Short-read methods like ATAC-seq miss regulatory elements smaller than 200 bp and those with lower protein occupancy. Using PacBio-enabled Fiber-seq, the Queitsch lab identified over 107,000 accessible chromatin regions in maize—half of which are invisible to conventional assays. The work also uncovers regulatory activity in LTR retrotransposons and validates Barbara McClintock's hypothesis about transposon activation in hybrids.
*What you'll learn*
- Identify regulatory elements that short-read ATAC-seq cannot detect
- Resolve single-molecule chromatin accessibility patterns in plant genomes
- Apply Fiber-seq to discover transposon-derived enhancers and promoters
- Analyze haplotype-resolved regulatory landscapes in maize hybrids
*Featured speakers*
- Christine Queitsch, PhD (University of Washington, Department of Genome Sciences)
*Chapters*
00:00 Introduction: Fiber-seq captures multiple regulatory features
02:49 Visualizing chromatin accessibility at single-molecule resolution
03:53 Why long reads matter for plant genomes
04:56 Fiber-seq doubles the regulatory landscape of maize
05:31 What ATAC-seq misses: short regulatory elements
07:00 LTR retrotransposon regulatory activity
09:46 Beyond peaks: ACR patterns and machine learning
11:45 Contextual UMAP captures regulatory element flavors
13:45 Maize hybrids and Barbara McClintock's hypothesis
16:30 Summary: A single-molecule view of gene regulation
*Resources*
- Fiber-seq overview: pacb.com/technology/fiber-seq
- Fiber-seq for epigenomics applications: pacb.com/applications/epigenomics
- Plant and animal genomics: pacb.com/applications/plant-and-animal-sciences
- Bubb & Hamm et al., Nature Plants, 2025 (referenced publication)
What regulatory regions in your favorite crop might be hiding from short-read methods? *Comment below.*
*Subscribe for more PacBio genomics content:*
youtube.com/@PacificBiosciences?sub_confirmation=1
Learn more about PacBio at pacb.com
Legal & Trademarks: pacb.com/legal-and-trademarks
#Fiberseq #PlantGenomics #Epigenomics
Discover how Fiber-seq reveals 50,000+ regulatory elements invisible to traditional chromatin accessibility methods. In this presentation from PAG 2026, Christine Queitsch, PhD shares findings that double our understanding of maize gene regulation.
Short-read methods like ATAC-seq miss regulatory elements smaller than 200 bp and those with lower protein occupancy. Using PacBio-enabled Fiber-seq, the Queitsch lab identified over 107,000 accessible chromatin regions in maize—half of which are invisible to conventional assays. The work also uncovers regulatory activity in LTR retrotransposons and validates Barbara McClintock's hypothesis about transposon activation in hybrids.
*What you'll learn*
- Identify regulatory elements that short-read ATAC-seq cannot detect
- Resolve single-molecule chromatin accessibility patterns in plant genomes
- Apply Fiber-seq to discover transposon-derived enhancers and promoters
- Analyze haplotype-resolved regulatory landscapes in maize hybrids
*Featured speakers*
- Christine Queitsch, PhD (University of Washington, Department of Genome Sciences)
*Chapters*
00:00 Introduction: Fiber-seq captures multiple regulatory features
02:49 Visualizing chromatin accessibility at single-molecule resolution
03:53 Why long reads matter for plant genomes
04:56 Fiber-seq doubles the regulatory landscape of maize
05:31 What ATAC-seq misses: short regulatory elements
07:00 LTR retrotransposon regulatory activity
09:46 Beyond peaks: ACR patterns and machine learning
11:45 Contextual UMAP captures regulatory element flavors
13:45 Maize hybrids and Barbara McClintock's hypothesis
16:30 Summary: A single-molecule view of gene regulation
*Resources*
- Fiber-seq overview: pacb.com/technology/fiber-seq
- Fiber-seq for epigenomics applications: pacb.com/applications/epigenomics
- Plant and animal genomics: pacb.com/applications/plant-and-animal-sciences
- Bubb & Hamm et al., Nature Plants, 2025 (referenced publication)
What regulatory regions in your favorite crop might be hiding from short-read methods? *Comment below.*
*Subscribe for more PacBio genomics content:*
youtube.com/@PacificBiosciences?sub_confirmation=1
Learn more about PacBio at pacb.com
Legal & Trademarks: pacb.com/legal-and-trademarks
#Fiberseq #PlantGenomics #Epigenomics
