| |
Fig. 1. Expression dynamics of selected genes during neural border and neural crest early development. (A) Expression of the some of the most commonly used markers for NB, NNE, NP and placodes. Upper row: Dorsal views of frog embryos at neural plate stage (stage 14, Nieuwkoop and Faber, 1994), stained for a selection of genes by whole-mount in situ hybridization: pax3, zic1 and msx1 are expressed at the NB, Six1 main expression delineates the preplacodal ectoderm (PPE) anteriorly, sox2 is expressed in the neural plate and epk marks the non neural ectoderm. Note the partial overlap between pax3 and sox2 in the lateral neural plate corresponding to the future dorsal part of the neural tube; and of Zic1 and Six1 in the PPE. Scale bar: 500 µm. Lower row: Cross-sections of neural plate stage 14 frog embryos stained by whole-mount in situ hybridization for the indicated genes. Pax3, zic1 and hes4 are expressed in the NB, sox2 is expressed in the neural plate with a partial overlap with pax3 in the lateral neural plate and epk is expressed in the non-neural ectoderm. Scale bar: 100 µm. (B) The comparison of the sequential temporal activation of selected genes in the NB/NC territory outlines the progressive specification of NB and NC in frog and chick embryos during gastrulation and neurulation. References for frog: AP2a (de Crozé et al., 2011), Id3 (Light et al., 2005, Kee and Bronner-Fraser, 2005), Pax3 (Bang et al., 1999, Monsoro-Burq et al., 2005), Gbx2 ((Li et al., 2009), Dlx5 (Luo et al., 2001a, Luo et al., 2001b; Steventon et al., 2012), Hes4 (Tsuji et al., 2003, Glavic et al., 2003), Zic1 (Mizuseki et al., 1998; Nakata et al., 1998), Snail1 (Aybar et al., 2003), c-myc ((Bellmeyer et al., 2003), Zic5 (Nakata et al., 2000), Sox9 (Spokony et al., 2002), Ednra (Bonano et al., 2008), Snail2 (Mayor et al., 1995; Aybar et al., 2003), Foxd3 (Sasai et al., 2001), Sox10 (Aoki et al., 2003; Honoré et al., 2003), Anosmin-1 (Bae et al., 2018), Tfap2e (Hong et al., 2014). References for chick: Pax7 (Basch et al., 2006); c-myc (Khudyakov et al., 2009; Keruoso et al., 2016); c-myb (Betancur et al., 2014); DNMT3a (Hu et al., 2012); Snail2 (Nieto et al., 1994; Endo et al., 2002); NSD3 (Jacques-Fricke et al., 2014); Foxd3 (Kos et al., 2001); Msx1 (Khudyakov et al., 2009); LSox5 (Perez-Alcala et al., 2004); Ets1 (Barembaum and Bronner, 2013); Sox10 (Cheng et al., 2000). |
