The structure of the non-degenerate and degenerating pronephros, of larval Rana temporaria, at different stages of the metamorphic cycle, was examined by electron microscopy. Extra-renal cellular components in the circulation were likewise investigated, and particular consideration was given to their relationships with the pronephric tubules whose regression would seem to be bound up with them....

We have used in situ hybridization to analyze Na,K-ATPase a and b subunit gene expression during zebrafish embryogenesis. The most striking finding is that each of the 14 Na,K-ATPase genes exhibits a distinct expression profile. All a and b subunit genes are expressed in the nervous system, although the pattern of expression in different regions varies dramatically. In peripheral tissues, three...

In our effort to understand genetic disorders of the photoreceptor cells of the retina, we have focused on intraflagellar transport in photoreceptor sensory cilia. From previous mouse proteomic data we identified a cilia protein Ttc26, orthologue of dyf-13 in Caenorhabditis elegans, as a target. We localized Ttc26 to the transition zone of photoreceptor and to the transition zone of cilia in cu...

THE pronephros of the chick is usually considered to be a vestigial organ. It only appears for a short period during early development and it is never functional as an excretory organ. From it, however, the primordium of the Wolffian duct is formed, by the confluence of the segmented pronephric tubules to a continuous strand of cells. This strand lengthens and extends into the posterior part of...

By analysing the expression and function of DN-associated genes during renal development in vivo, it may be possible to shed light on their pathogenic roles in the disease. The embryos of the African clawed frog Xenopus laevis provide a useful model for analysing early embryonic development, particularly organogenesis. Their rapid, external development and the large size of embryos allow for ea...

Wnts have been implicated in metanephric kidney development. To determine whether Frizzleds, the genes that encode Wnt receptors, are present at early stages of nephrogenesis, we examined the expression of several recently identified Frizzled genes in the chick by in situ hybridization. Here we report the cloning and characterization of chick Frizzled-4 (cFz-4), which we found to be expressed i...

The slit diaphragm (SD) is a highly specialized intercellular junction between podocyte foot processes and is crucial in the formation of the filtration barrier in the renal glomeruli. Zebrafish Nephrin and Podocin are important in the formation of the podocyte SD and mutations in NEPHRIN and PODOCIN genes cause human nephrotic syndrome. In the present study, the zebrafish Podocin protein was o...