Xenbase Image ID: 148750

Fig. 4. Depletion of maternal syntabulin causes embryo ventralization and decreases the expression of dorsal genes. (A) Wild type oocyte showing normal syntabulin expression. (B) 91% (n=12) of oocytes injected with 10 ng of phosphorothioate-modified DNA antisense oligo targeting syntabulin (sybu AS) showed no expression of the maternal mRNA 48 h after microinjection. Hybrids between mRNA and DNA are efficiently degraded by RNase H. (C) Depletion of syntabulin in injected oocytes assessed by quantitative RT-PCR (qPCR). Groups of five oocytes were used. Injection of different amount of sybu AS (5 or 10 ng) caused a strong decrease of mRNA levels in a dose-dependent fashion. WT indicates uninjected oocytes. (D, E) Representative wild type and sybu AS-injected embryos obtained from host transfer experiments. Note the complete absence of axial structures in sybu-depleted embryos. (F) In wild type embryos, the ventral marker sizzled (szl) is expressed in a ventral domain at stage 12. (G) Age-matched sybu-depleted embryos (sybu-AS) display radial ectopic szl expression, indicating strong expansion of ventral tissues. (H) In wild type embryos at stage 22, szl has an anterior and a posterior domain of expression. (I) sybu-depleted embryos have a radially expanded szl ventro-posterior expression domain. Strong expansion of ventral tissue was observed in 70% of the embryos (n=36). Arrowheads point to the blastopore. (J) Quantification of the ventralization phenotype after syntabulin depletion. Note the high penetrance of complete ventralization (dorso-anterior index 0) in antisense injected embryos (84%); data from 4 independent host transfer experiments (n=61). (K–N) qRT-PCR analyses showing significant decreases in the dorsal markers siamois, Xnr3 and chordin, and a strong increase of the ventral marker sizzled after maternal knockdown of syntabulin. Error bars indicate the standard error from three independent host transfer experiments Image published in: Colozza G and De Robertis EM (2014) Copyright © 2014. Image reproduced with permission of the publisher and the copyright holder. This is an Open Access article distributed under the terms of the Creative Commons Attribution License. Gene Synonyms Species Stage(s) Tissue sybu.S golsyn, ocsyn, snphl, syntabulin X. laevis Throughout NF stage 1 vegetal pole Image source: Published Larger Image Printer Friendly View

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