Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2012 Mar 20;10(3):e1001286. doi: 10.1371/journal.pbio.1001286

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

Xu et al.

This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.

PMC Copyright notice

(A–F) Injection of NFL into ventral vegetal cells at the eight-cell stage induced partial secondary axes. Wild-type (WT) embryos (stage 28) (A and D). Injection of Wnt8 mRNA (10 pg) into ventral vegetal cells in eight-cell embryos induces complete secondary axis formation (stage 28) (69% of injected embryos showed secondary axes, n = 85) (B and E). NFL mRNA (600 pg total; 200 pg each) co-injection of ventral vegetal cells in eight-cell embryos induces partial secondary axis formation (stage 28) (45% of co-injected embryos showed secondary axes, n = 105) (C and F). Whole-mount in situ hybridization for Sox3 in stage 28 embryos (D–F). Note that NFL induces Sox3 expression in the partial secondary axis (arrowhead in [F]). The black lines in (A–C) indicate the section planes in (G–I), respectively. (G–I) Histological sections of embryos at stage 30. A wild-type embryo (G). Wnt8 mRNA injection induced both secondary neural tube and notochord (H). NFL co-injection induced secondary neural tube but not notochord formation (I). Arrowhead: neural tube; arrow: notochord. (J–L) Immunostaining of notochords with the monoclonal antibody MZ15. Wild-type embryo with single notochord (all examined embryos) (J and J'). An embryo injected ventrally with Wnt8 mRNA (10 pg) showed two notochords (induced secondary notochord and the primary notochord) (all examined embryos with secondary axes) (K and K'). An embryo injected ventrally with NFL (200 pg each) showed only the primary notochord (arrows), with notochord tissue absent in the partial secondary axis (arrowheads) (all examined embryos with partial secondary axes) (L and L'). Embryos are at stage 30. (M–R) NFL and Wnt8 induced Chordin expression in different domains in the ventral cells. Whole-mount in situ hybridization was used to evaluate Chordin expression in stage 10 embryos. Chordin expression in wild-type early gastrula (M and P). Wnt8 mRNA (10 pg) injection into ventral vegetal cells induced Chordin expression both in the superficial layer and in the deep layer of the marginal zone (87.5% of injected embryos showed the expression in both layers, n = 24) (N). Injection of NFL mRNAs (200 pg each) into the same domain induced Chordin expression mainly in the superficial layer (76% of injected embryos showed the expression, n = 30) (O). Injection of Wnt8 into the ventral-animal cells of eight-cell embryos induced Chordin expression both in the ectoderm and in the mesoderm (84% of injected embryos showed the expression in both layers, n = 25) (Q). Injection of NFL mRNAs (200 pg each) into the same domain of eight-cell embryos induced Chordin expression only in the ectoderm (72% of injected embryos showed the expression, n = 32) (R). Arrowheads: superficial layer (O) or ventral ectoderm (R); arrows: deep layers on the ventral side. All embryos in (M–R) are shown with their dorsal sides to the right. Dotted lines delineate the superficial layer and deeper layer on the ventral side.