Post-embryonic pericardial cells of Drosophila are required for overcoming toxic stress but not for cardiac function or adult development.

The Drosophila heart is composed of two cell types: cardioblasts (CB) and pericardial cells (PC). Whereas CBs act to maintain rhythmic contractions, the functions of accessory PCs are not clear. The close association between these two cell types has led to speculation of a cardio-regulatory role for PCs. However, we find that viability and cardiac function are normal in larvae following post-embryonic ablation of PCs by induced cell death. Removal of PCs during the larval instars or before metamorphosis results in viable and fertile adults. Interestingly, such animals have a reduced lifespan and increased sensitivity to toxic chemicals. Thus, although PCs may have an embryonic role in cardiogenesis, they do not appear to play a part later in cardiac function as suggested. However, the role of PCs in the uptake and sequestering of toxins, their sensitivity to toxic stress and the decreased lifespan of animals without PCs indicate the importance of PCs in organismal homeostasis.