Sb bicolor BTx623 CAS T2T Assembly and Gene Annotation
About Sorghum BTx623
BTx623, a widely used reference genome for Sorghum bicolor, is known for its compact genome size of approximately 719 Mb. This diploid cereal crop has 10 haploid chromosomes and plays a crucial role in functional genomics studies of C4 plants. Originally released in 2005, BTx623 has undergone multiple updates, with the latest telomere-to-telomere (T2T) assembly providing a gap-free, highly contiguous genome (Yuan et al., 2024). It is primarily used in studies focused on sorghum’s adaptation to semi-arid environments and its potential as a biofuel source.
Assembly
- DNA Extraction & Sequencing: High molecular weight (HMW) DNA from young leaves was extracted and sequenced using PacBio HiFi, Oxford Nanopore Technology (ONT) ultra-long reads, and Illumina short reads. ONT and PacBio reads were assembled using Hifiasm, and Hi-C data was used for scaffolding.
- Genome Assembly: The T2T assembly resulted in a 719 Mb genome, with all gaps closed and misassembled regions corrected. The assembly showed high coverage and uniform distribution across chromosomes, with an N50 of 58.99 Mb.
Annotation
Repeats & Gene Models: 72.4% of the genome consists of repetitive elements, including transposable elements (TEs) and tandem repeats. Gene annotation identified 36,950 protein-coding genes, including 3565 newly annotated genes. Compared to earlier versions, BTx623-T2T fills centromeric and telomeric gaps, with 43.6 Mb of new sequence, enhancing gene content and structural accuracy. The genome offers improved accuracy for genome-wide association studies (GWAS) and variant analysis, particularly in repetitive and centromeric regions.
Regulation
Variation
References
- Yuan et al. 2024. “A Complete Assembly of the Sorghum BTx623 Reference Genome.” Plant Communications.
Links
More information
General information about this species can be found in Wikipedia.
