Optimal probe length varies for targets with high sequence variation: implications for probe library design for...

Area of Science:

• Genomics
• Bioinformatics
• Molecular Biology

Background:

• Sequencing by hybridisation (SBH) offers cost-effective DNA sequencing.
• SBH efficiency relies on probe library design for maximal information at minimal cost.
• Probe length presents a trade-off between sequence uniqueness and library size.

Purpose of the Study:

• Investigate the impact of probe length, reference sequences, and thermal filtering on probe library design.
• Optimize probe library design for highly variable DNA target sequences.

Main Methods:

• Designed overlapping probe libraries for diverse, highly variable drug target genes.
• Utilized known sequence information and developed formal terminology for probe library design.
• Analyzed the effect of probe length (12-19 nt), sequence variability, and thermal filtering stringency.

Main Results:

• Probe library coverage varied significantly across targets, with some below 30%.
• Optimal probe length is sequence-dependent, ranging from 12 to 19 nucleotides.
• Optimal probe length cannot be predicted by simple inspection of gene sequences.

Conclusions:

• Probe library design for highly variable targets is inherently target-specific.
• Detailed analysis of each target is necessary for optimal probe length and reference sequence selection.
• Shorter probes can sometimes yield better information for highly variable sequences, necessitating advanced design tools.