The putative Notch ligand HyJagged is a transmembrane protein present in all cell types of adult Hydra and upregulated at the boundary between bud and parent

Abstract

BackgroundThe Notch signalling pathway is conserved in pre-bilaterian animals. In the Cnidarian Hydra it is involved in interstitial stem cell differentiation and in boundary formation during budding. Experimental evidence suggests that in Hydra Notch is activated by presenilin through proteolytic cleavage at the S3 site as in all animals. However, the endogenous ligand for HvNotch has not been described yet.ResultsWe have cloned a cDNA from Hydra, which encodes a bona-fide Notch ligand with a conserved domain structure similar to that of Jagged-like Notch ligands from other animals. Hyjagged mRNA is undetectable in adult Hydra by in situ hybridisation but is strongly upregulated and easily visible at the border between bud and parent shortly before bud detachment. In contrast, HyJagged protein is found in all cell types of an adult hydra, where it localises to membranes and endosomes. Co-localisation experiments showed that it is present in the same cells as HvNotch, however not always in the same membrane structures.ConclusionsThe putative Notch ligand HyJagged is conserved in Cnidarians. Together with HvNotch it may be involved in the formation of the parent-bud boundary in Hydra. Moreover, protein distribution of both, HvNotch receptor and HyJagged indicate a more widespread function for these two transmembrane proteins in the adult hydra, which may be regulated by additional factors, possibly involving endocytic pathways.

Innexin gap junctions in nerve cells coordinate spontaneous contractile behavior in Hydra polyps

“…Confocal images were acquired with a Leica (Leica Microsystems, Wetzlar, Germany) TCS SP confocal laser-scanning microscope as described previously 30 .…”

Hydra, a model system to trace the emergence of boundaries in developing eumetazoans

“…At the same time the metalloprotease MMP-A3 is expressed in the kringelchen positive cells (Münder et al, 2010). From now on, kringelchen, MMP-A3, HyDsh and HyJagged expression are restricted to parent tissue whereas foot specific genes are expressed in the newly forming bud peduncle (Sudhop et al, 2004;Prexl et al, 2011). Interestingly, HyWnt-8 is expressed in cells confining the peduncle at the side of the bud (Philipp et al, 2009).…”

“…3) might depend on transiently forming intersections. Notch and FGFR signalling are clearly involved in forming the sharp boundary between bud and parent (Münder et al, 2010;Prexl et al, 2011), a role of ephrin signalling is likely.…”

“…Hydra has all major components for bona fide Notch signalling including a well conserved Notch receptor (HvNotch), a putative Notch ligand HyJagged (Prexl et al, 2011), components of the g-secretase complex including presenilin, metalloproteases of the ADAM family (Kasbauer et al, 2007;Münder et al, 2010). Genes encoding Su(H) (CBF) and the transcriptional repressor HyHes have been identified as well as modulators of Notch signalling such as Fringe and Numb.…”

Avaliação ecotoxicológica de lodo gerado por estação de tratamento de água

“…VERNOUILLET et al, 2010;FERREIRA et al, 2011;PREXL et al, 2011). Possuem coloração avermelhada devido à presença de hemoglobina, que os ajuda a tolerar períodos de baixas concentrações de oxigênio e auxilia na seleção dos organismos e no preparo dos testes.…”