Rab11 regulates planar polarity and migratory behavior of multiciliated cells in Xenopus embryonic epidermis

Abstract

Background Xenopus embryonic skin is composed of the superficial layer with defined apicobasal polarity and the inner layer lacking the apical domain. Multiciliated cells (MCCs) originate in the inner layer of the epidermal ectoderm and subsequently migrate to the surface. How MCCs acquire the apicobasal polarity and intercalate into the superficial layer during neurulation is largely unknown. As Rab11-dependent vesicle trafficking has been implicated in ciliary membrane assembly and in apical domain formation in epithelial cells, we assessed the involvement of Rab11 in MCC development. Results Here we report that Rab11 is specifically enriched and becomes apically polarized in skin MCCs. Interference with Rab11 function by overexpression of a dominant negative mutant or injection of a specific morpholino oligonucleotide inhibited MCC intercalation into the superficial layer. Dominant negative Rab11-expressing MCC precursors revealed intrinsic apicobasal polarity, characterized by the apical domain that is not normally observed in inner layer cells. Despite the presence of the apical domain, the cells with inhibited Rab11 function were randomly oriented relative to the plane of the tissue, thereby demonstrating a defect in planar polarity. Conclusion These results establish a requirement for Rab11 in MCC development and support a two-step model, in which the initial polarization of MCC precursors is critical for their integration into the superficial cell layer.

Vangl2 cooperates with Rab11 and Myosin V to regulate apical constriction during vertebrate gastrulation

“…6D-F). Blastopore formation was also inhibited when Rab11 was depleted with a previously characterized specific MO (Kim et al, 2012), further supporting a role for Rab11 in apically constricted blastopore cells (Fig. 6G).…”

“…We examined the localization of Rab11, a marker of the recycling endosome (Bryant et al, 2010;Mizuno-Yamasaki et al, 2012), which has been implicated in planar polarization of Xenopus multiciliated skin cells (Kim et al, 2012) and the neural tube Ossipova et al, 2014). In early ectoderm and in the non-constricting epithelial layer of the marginal zone cells, Rab11 is detected largely at cell junctions (supplementary material Fig.…”

“…Therefore, we studied a function for Rab11 in blastopore formation using a dominant-negative mutant, Rab11S25N (Kim et al, 2012). Rab11S25N, but not the wild-type Rab11, interfered with the appearance of the dorsal lip and delayed blastopore closure ( Fig.…”

“…Hall, Memorial Sloan Kettering Cancer Center, New York, USA). Xenopus Rab11 constructs were as described previously (Kim et al, 2012). GFP-MyoVT-pCS2 was created by subcloning the insert from the original construct (Lapierre et al, 2001).…”

“…Cytoplasmic GFP (50-100 pg) RNA was co-injected with MOs or RNAs as a lineage tracer. The Rab11 MO (5′-TACCCATCGTCGCGGCACTTCTGAC-3′) (Kim et al, 2012) and Vangl2/Stbm MO (Darken et al, 2002) were as described previously. The sequence of the control MO was 5′-GCTTCAGCTAGTGACACATGCAT-3′ .…”