Professional graphics require code
In order to visualize the location of oligonucleotide primers as well as structural rearrangements in plastid genomes, I wrote some Latex code.
\documentclass[margin=10pt]{standalone}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}[line cap=rect,line width=3pt]
\draw[] (0,0) circle [radius=8cm];
% Draw small intervals, label small intervals
\foreach \angle [count=\xi, evaluate=\xi as \xx using int(\xi*10)] in {157.5,135,...,-157.5,-180}{
\draw[line width=1.5pt] (\angle:7.8cm) – (\angle:8.2cm);
\node[font=\large] at (\angle:9cm) {\xx ,000};
}
% Draw quater intervals
\foreach \angle [] in {0,-90,-180,-270}{
\draw[line width=3pt] (\angle:7.7cm) – (\angle:8.3cm);
}
% Draw origin
\draw[line width=3pt] (-182:7.7cm) – (-182:8.3cm);
\node[font=\large] at (-182:9cm) {origin};
% Draw IRs
\draw[line width=5pt,gray] ([shift=(-90:5cm)]5,0) arc (-45:-90:7cm);
\draw[line width=5pt,gray] ([shift=(-180:5cm)]0,-5) arc (-135:-180:7cm);
% Label IRs
\node[font=\large, gray] at (-157.5:6.5cm) {IRa};
\node[font=\large, gray] at (-67.5:6.5cm) {IRb};
\end{tikzpicture}
\end{document}
When compiled, the above code generates the following image:
A thank you goes to some fellow LaTeX Stack Exchange users, who assisted with the above code.