# A way to draw genes using TikZ

To represent the organization of genes in the chromosomes of bacteria (for instance), biologists use series of arrows looking like that:

Is there a TikZ library to draw diagrams such as this one - or is it trivial to write one ?

• Welcome to TeX.SX! The short answer is that it is possible to do this but I have to warn you that questions of the form "Please draw this for me", which show no effort on the part of OP, often don't get answered. You will get more help if you post some code showing what you have tried and give a minimal working example. The tikz library arrows.meta, in section 16.5 of the manual, is a good place to start. – Andrew Nov 21 '17 at 9:49

Not trivial, but not too difficult:

\documentclass[tikz,border=2mm]{standalone}
\usetikzlibrary{positioning, shapes.arrows, backgrounds}

\begin{document}
\begin{tikzpicture}[
myarrow/.style={single arrow,
draw=blue!80,
fill=#1,
}]

\node[myarrow=violet, label={[violet]below:cooA}, minimum height=1cm] (cooA) {};

\node[circle, draw=blue!80, fill=blue!60, right=2mm of cooA] (c) {};

\node[myarrow=blue!60, label={[blue!60]below:cooS}, minimum height=1.5cm, right=1mm of c] (cooS) {};

\node[myarrow=red, label={[red]below:cooC}, minimum height=.7cm, right=0pt of cooS] (cooC) {};

\begin{scope}[on background layer]
\draw[blue!80] ([xshift=-1cm]cooA.west)--(cooC.east);
\end{scope}

\end{tikzpicture}
\end{document}


• Looks nice ! I wasn't aware of the arrows node shapes... Maybe this could be turned into a "genes" library some day – Vincent Fourmond Nov 21 '17 at 10:05