Weavers, H. et al. The insect nephrocyte is a podocyte-like cell with a filtration slit diaphragm. Nature 457, 322–327 (2009).

A European study published in Nature has discovered a remarkable similarity between insect nephrocytes and the glomerular podocytes of the human kidney, which suggests that these nephrocytes could be a simple model in which to study podocyte diseases.

The two main components of the podocyte slit diaphragm are nephrin and Neph1. Researchers, led by Helen Skaer of Cambridge University and Mar Ruiz-Gómez of the Autonomous University of Madrid, were studying the roles of Drosophila homologs of these proteins in renal and myoblast development when they became interested in expression of these proteins in nephrocytes. Their investigations revealed that nephrocytes possess a size-selective filtration diaphragm to which the nephrin and Neph1 homologs specifically co-localize. “We were immediately struck by the extraordinary similarities between nephrocyte and podocyte fine structure”, says Skaer. “The molecular structures of the insect nephrocyte diaphragm and the slit diaphragm of vertebrate podocyte cells are remarkably conserved.”

The team also investigated the effect of mutations in the Drosophila equivalents of nephrin and Neph1, and showed that mutant nephrocytes fail to develop diaphragms. “It is very striking that the effects of mutations in vertebrate nephrin or Neph1 (as seen in human disease) are the same as those in the fly homologs,” observes Skaer, “namely loss of the diaphragm, effacement of the membrane infolding, and cell death”.