Oda16/Wdr69 is essential for axonemal dynein assembly and ciliary motility during zebrafish embryogenesis

Abstract

In the alga Chlamydomonas reinhardtii, Oda16 functions during ciliary assembly as an adaptor for intraflagellar transport of outer arm dynein. Oda16 orthologs only occur in genomes of organisms that use motile cilia, however, such cilia play multiple roles during vertebrate development and the contribution of Oda16 to their assembly remains unexplored. We demonstrate that the zebrafish Oda16 ortholog (Wdr69) is expressed in organs with motile cilia and retains a role in dynein assembly. Antisense morpholino knockdown of Wdr69 disrupts ciliary motility and results in multiple phenotypes associated with vertebrate ciliopathies. Affected cilia included those in Kupffer's vesicle, where Wdr69 plays a role in generation of asymmetric fluid flow and establishment of organ laterality, and otic vesicles, where Wdr69 is needed to develop normal numbers of otoliths. Analysis of cilium ultrastructure revealed loss of outer dynein arms in morphant embryos. These results support a remarkable level of functional conservation for Oda16/Wdr69.

The role of hair cells, cilia and ciliary motility in otolith formation in the zebrafish otic vesicle

“…The correlation between otolith defects and ciliary dysfunction in the zebrafish is well documented (Panizzi et al, 2007;Colantonio et al, 2009;Neugebauer et al, 2009;Serluca et al, 2009;Wilkinson et al, 2009;Gao et al, 2010;Yu et al, 2011). Nevertheless, the complete loss of cilia causes surprisingly mild otolith defects.…”

“…These organelles are present on the apical surface of most vertebrate cells and are involved in sensory, signalling and mechanical processes (Bisgrove and Yost, 2006;Ishikawa and Marshall, 2011). Every cell of the zebrafish OV epithelium is monociliated (Riley et al, 1997), and many genes involved in ciliogenesis, intraflagellar transport, ciliary movement, stability and function are expressed in the OV (Tsujikawa and Malicki, 2004;Bisgrove et al, 2005;Omori and Malicki, 2006;Pathak et al, 2007;Omori et al, 2008;SullivanBrown et al, 2008;van Rooijen et al, 2008;Yu et al, 2008;Colantonio et al, 2009;Wilkinson et al, 2009;Gao et al, 2010;Glazer et al, 2010;Kang et al, 2010;May-Simera et al, 2010;Becker-Heck et al, 2011;Clément et al, 2011;Pathak et al, 2011;Ravanelli and Klingensmith, 2011;Rothschild et al, 2011;Yu et al, 2011). Sensory hair cells in the ear each bear a specialised cilium known as the kinocilium.…”

Cilia and coordination of signaling networks during heart development

“…42 Thus, motile as well as nonmotile cilia with variable architecture of axonemal microtubules are present in multiple tissues and organs throughout the body where they regulate key events during development and in the adult. Therefore, defects in genes required for ciliary assembly, maintenance, motility, and/or sensory functions may lead to a series of syndromic diseases and developmental disorders referred to as ciliopathies.…”

Lethal giant larvae 2 regulates development of the ciliated organ Kupffer’s vesicle

“…lgl2 and previously described sox17, spaw, lft1 and shha cDNA constructs (Alexander and Stainier, 1999;Long et al, 2003;Bisgrove et al, 1999;Krauss et al, 1993) were used to generate in vitro-synthesized RNA probes labeled with digoxygenin (Roche DIG RNA Labeling Kit). In situ RNA hybridizations were performed as described (Gao et al, 2010).…”