Related Experiment Video
Updated: May 2, 2026

Candidate Gene Testing in Clinical Cohort Studies with Multiplexed Genotyping and Mass Spectrometry
Published on: June 21, 2018
Comprehensive detection of genes causing a phenotype using phenotype sequencing and pathway analysis.
Marc Harper1, Luisa Gronenberg2, James Liao3
1Institute for Genomics and Proteomics, University of California Los Angeles, Los Angeles, California, United States of America.
This study introduces a novel pathway-based phenotype sequencing analysis to identify genetic causes of metabolic phenotypes. The method significantly enhances detection sensitivity, revealing diverse genetic pathways influencing the PEP/OAA node in E. coli.
Area of Science:
- Functional Genomics
- Metabolic Engineering
- Systems Biology
Background:
- Identifying all genetic contributors to a phenotype is crucial for understanding biological systems.
- Metabolic phenotypes, particularly the phosphoenolpyruvate/oxaloacetate (PEP/OAA) node in E. coli, are vital for numerous metabolic pathways and biofuel research.
- Previous methods for identifying genetic causes of phenotypes had limitations in sensitivity and comprehensiveness.
Purpose of the Study:
- To develop and validate a high-throughput sequencing analysis combined with an experimental design for detecting independent genetic causes of phenotypes.
- To improve the sensitivity and comprehensiveness of identifying genetic factors influencing metabolic phenotypes.
- To apply the developed approach to the PEP/OAA metabolic node in E. coli.
Main Methods:
- A pathway-based phenotype sequencing analysis (pathway-phenoseq) was developed.
- The method was tested on 24 mutant strains of E. coli with a known metabolic phenotype.
- High-throughput sequencing data was analyzed to identify statistically significant gene groups associated with the phenotype.
Main Results:
- The pathway-phenoseq analysis identified five gene groups (12 genes) as statistically significant causes of the PEP/OAA metabolic phenotype.
- These identified gene groups showed clear biological relevance to PEP metabolite levels or OAA production.
- High-scoring gene groups exhibited evidence of positive selection pressure, unlike other genomic regions.
Conclusions:
- The developed pathway-based phenotype sequencing analysis significantly enhances the detection sensitivity for genetic causes of metabolic phenotypes.
- The approach successfully identified key genetic factors influencing the PEP/OAA node in E. coli, relevant to biofuel research.
- The findings highlight the utility of this method for comprehensive genetic discovery in functional genomics.
Related Concept Videos
Genetic Screens
Forward genetic screens
Forward or “classical” genetic screens involve creating random mutations in an organism’s DNA using radiation, mutagens, or insertion of additional bases, which...
Pharmacogenomics: Identification of New Drug Targets
Genome-wide Association Studies-GWAS
GWAS does not require the identification of the target gene involved in...
Genomics
Epistasis Analysis

