Expression of mouse dchs1, fjx1, and fat‐j suggests conservation of the planar cell polarity pathway identified in drosophila

Abstract

The dachsous (ds), fat (ft), and four-jointed (fj) genes have been identified in Drosophila as part of a signaling pathway that regulates planar cell polarity (PCP). A homologous PCP signaling pathway has also been identified in vertebrates, but nothing is known thus far about the conservation of Ds/Ft/Fj signaling. Here we analyzed and compared for the first time the expression patterns of all ds, ft and fj homologs in the mouse. During embryogenesis, expression analysis was performed by RNA in situ hybridization and in adult organs by real time PCR. As in Drosophila, we detected a complementary expression of fjx1 and dchs1 in organs like kidney, lung, and intestine. The ubiquitous expression of ft in several tissues in Drosophila appears to be split into an epithelial expression of fat1/fat3 and a mesenchymal expression of fat-j. These data are compatible with a conservation and subfunctionalization of the Drosophila Ds, Fj, and Fat signaling in higher vertebrates. Developmental Dynamics 234:747-755, 2005.

Regulation of leg size and shape: Involvement of the Dachsous‐fat signaling pathway

“…In mammals, four types of Ft proteins, namely Ft1, Ft2, Ft3, and Ft4, have been identified (Rock et al, 2005;Tanoue and Takeichi, 2005). Among them, Ft4 is the vertebrate counterpart of Drosophila Ft based on their sequence similarity (Rock et al, 2005;Matakatsu and Blair, 2006).…”

“…Among them, Ft4 is the vertebrate counterpart of Drosophila Ft based on their sequence similarity (Rock et al, 2005;Matakatsu and Blair, 2006). Recently, Saburi et al (2008) reported phenotypes of Ft4-null mice.…”

“…Saburi et al (2008) demonstrated that the Ft-Ds-Fj PCP signaling cassette is conserved in vertebrates and provides experimental evidence to support the hypothesis that polycystic kidney disease can be caused by defective PCP signaling. On the other hand, two types of Ds, Ds1 and Ds2, have been identified in mammals (Rock et al, 2005). At the mRNA level, the former is broadly expressed in mouse embryos, whereas the latter exhibits restricted expression (Rock et al, 2005).…”

“…On the other hand, two types of Ds, Ds1 and Ds2, have been identified in mammals (Rock et al, 2005). At the mRNA level, the former is broadly expressed in mouse embryos, whereas the latter exhibits restricted expression (Rock et al, 2005). Until now, Ft1 is expressed in rat limb buds (Ponassi et al, 1999), and expression of other Ft proteins in mouse limb buds has not yet been described.…”

FatJ acts via the Hippo mediator Yap1 to restrict the size of neural progenitor cell pools

“…Drosophila Fat (dFat) was first identified as a putative tumour suppressor gene involved in planar cell polarity and tissue size regulation via the Hippo signalling pathway (Mahoney et al, 1991;Matakatsu and Blair, 2004;Willecke et al, 2006). Of the four vertebrate orthologues of dFat, Fat4 (also called FatJ) shows the greatest homology to dFat (Matakatsu and Blair, 2006) and is expressed in a variety of tissues with active PCP signalling (Rock et al, 2005), including the kidney, where loss of Fat4 alters orientated cell divisions and leads to kidney dysfunction. Fat4 additionally plays a role within the CNS: loss of Fat4 expression in the cerebellum reduces the apical membrane compartment, suggesting a role in apical-basal polarity (Ishiuchi et al, 2009).…”