Fig. 3

Perturbation of Hox expression disrupts oral patterning during gastrulation. Developmental time series of anterior, NvAx6 (a–e), and central/posterior, NvAx1 (f–j), Hox mRNA expression at blastula (a, f), early gastrula (b, g), mid gastrula (c, h), early planula (d, i), and late planula stages (e, j; images reproduced from ref¹⁵.). k–o Gastrulation defects due to disruption of anterior (NvAx6) and central/posterior (NvAx1) Hox expression through microinjection of antisense translation blocking morpholinos (knockdown) or in vitro transcribed mRNA (overexpression). k Fluorescent phalloidin-labeled embryo during final stages of gastrulation (48hpf) with distinct ectodermal(Ec) and endo-mesodermal(En) tissue layers delineated by the early pharynx (P) (white-dashed line delineates the pharynx from endomesoderm). l Knockdown of anterior Hox (NvAx6) blocks invagination of the presumptive endomesoderm. m Overexpression of central/posterior Hox (NvAx1) mRNA also blocks gastrulation and produces gastrula stage embryos with reduced axial morphology. n Overexpression of anterior Hox (NvAx6) mRNA and o knockdown of the central/posterior Hox gene (NvAx1) disrupts pharynx development and produces ectopic oral tissue at the blastopore (white arrowhead). p–r In situ hybridization of anterior Hox (NvAx6) at 24hpf in control (p), central/posterior Hox knockdown (q), and central/posterior Hox overexpression treatments (r). s–u In situ hybridization of central/posterior Hox (NvAx1) at 24hpf in control (s), anterior Hox knockdown (t), and anterior Hox overexpression treatments (u). Images were compiled from at least three separate experiments and the number of similar phenotypes is noted as a fraction in the lower left-hand corner (e.g., k—77 out of 80 total animals exhibited the phenotype). Scale bars are 50 µm