CPJSdraw

CPJSdraw visualizes and analyzes junction sites and the tetrad structure (two inverted repeats, large single-copy, small single-copy) of chloroplast genomes to detect IR expansion/contraction and annotate adjacent gene transcription directions.

Key Features:

• Accurate Visualization: Visualizes junction sites and corrects irregularities in the linearized genome starting point to ensure precise IR and single-copy region boundaries.
• Tetrad Structure Display: Displays the tetrad organization of chloroplast genomes, including two inverted repeats (IR), a large single-copy (LSC) region, and a small single-copy (SSC) region.
• Multiple Genome Comparison: Compares and visualizes junction sites across any number (≥1) of chloroplast genomes simultaneously.
• Gene Transcription Indication: Annotates the transcription direction of genes adjacent to junction sites.
• IR Expansion/Contraction Indication: Highlights IR expansion and contraction events at junction sites.
• Applicability: Applicable to diverse chloroplast genome datasets for comparative analyses of junction dynamics.

Scientific Applications:

• Evolutionary Dynamics: Study IR contraction and expansion and their contributions to chloroplast genome evolution.
• Comparative Genomics: Compare junction-site organization and tetrad structures across species or samples.
• Gene Expression Analysis: Investigate relationships between structural changes at junctions and adjacent gene transcription direction.
• Structural Characterization: Precisely define IR/LSC/SSC boundaries to characterize chloroplast DNA organization.

Methodology:

Formats the starting point of irregular linearized chloroplast genomes and corrects junction site assignments between inverted repeat (IR) and large/small single-copy regions; handles multiple genomes and annotates adjacent gene transcription directions and IR expansion/contraction.