1. Parsing the Heart: Genetic Modules for Organ Assembly
Mark C Fishman, Eric N Olson 
Cell 
Volume 91, Issue 2, Pages (October 1997)
DOI: /S (00)

2. Figure 1 Key Stages in the Development of the Vertebrate Heart
Key stages include the earliest assembled heart tube (left), the tube after looping (middle), and the adult four-chambered heart (right). Through the looping stage, the heart tubes of all vertebrates are nearly identical. Fish, lacking atrial and ventricular septa, have a single atrium and a single ventricle. LA, left atrium; LV, left ventricle; RA, right atrium; RV, right ventricle; PA, pulmonary artery (carrying deoxygenated blood to the lungs); Ao, aorta (carrying oxygenated blood to the body).
Cell  , DOI: ( /S (00) )

3. Figure 2
Modules Added to a Presumptive Ancestral Chordate Heart to Generate a Four-Chambered Vertebrate Heart
RA, right atrium; RV, right ventricle; LA, left atrium; LV, left ventricle.
Cell  , DOI: ( /S (00) )

4. Figure 3
Stages of Heart Development at Which Arrest Occurs with Loss-of-Function Mutations in Homologous Genes in Drosophila and Mouse
Some of the same genes involved in cell specification and differentiation appear to play additional roles in later steps of vertebrate heart development.
Cell  , DOI: ( /S (00) )