Gene mapping via bulked segregant RNA-Seq (BSR-Seq)

Area of Science:

• Plant genetics
• Molecular biology
• Genomics

Background:

• Bulked segregant analysis (BSA) is crucial for mapping genes controlling mutant phenotypes.
• Traditional BSA relies on pre-existing polymorphic genetic markers.
• Identifying novel markers can be a bottleneck in gene mapping.

Purpose of the Study:

• To introduce BSR-Seq, a modified BSA approach utilizing RNA-Seq data.
• To enable efficient gene mapping in populations lacking identified polymorphic markers.
• To streamline gene cloning experiments by integrating multiple data types.

Main Methods:

• RNA-Sequencing (RNA-Seq) data from mutant and wild-type pools.
• De novo single nucleotide polymorphism (SNP) discovery from RNA-Seq data.
• Empirical Bayesian analysis for quantitative genotyping of BSA samples.
• Gene expression profiling from RNA-Seq data.

Main Results:

• BSR-Seq successfully mapped the glossy3 (gl3) gene in maize to a ~2 Mb interval.
• Identified a single down-regulated gene within the mapping interval as the gl3 gene.
• Confirmed gl3 encodes a myb transcription factor involved in fatty acid biosynthesis.
• Demonstrated the utility of BSR-Seq for gene cloning.

Conclusions:

• BSR-Seq offers an efficient, marker-independent strategy for gene mapping.
• Integrating RNA-Seq for BSA accelerates gene discovery and cloning.
• This method provides simultaneous gene mapping and expression analysis.