Localization of camera eye-specific genes in the pygmy squid embryos. (A-C) Whole-mount in situ hybridization with probes for the Ets-4 homolog. (D, E) Whole-mount in situ hybridization with probes for the Hla-b associated transcript homolog. (F) Whole-mount in situ hybridization with probes for the HMGb3 homolog. (A) Tissue surrounding the eye primodia (E) and tips of the arms (A) at stage 20 expressed the Ets-4 homolog. The Ets-4 transcripts were not detected in the mantle (M). (B) The Ets-4 transcript localized in the external part of the optic lobes (OL) and the central part of brain at stage 22. The yolk sac (Y) was removed using forceps. (C) Specific staining was localized in the optic lobes and central part of the brain at stage 25. The Ets-4 homolog was also expressed in the funnel organ (F). (D) A horizontal cryosection at the dotted line in (C). The Ets-4 transcripts appeared to be localozed in the part of the brain (the middle esophageal mass). Up side showes dorsal of the body. (E) A horizontal cryosection at the solid line in (C). The Ets-4 transcripts apper to be restricted in glanular cell layer (GL) in the optic lobes. (F) The HMGb3 transcripts were restricted to the internal part of the optic lobes at stage 25. Non-specific staining was found in the shell sac (S), as shown in the control experiment (Figure 5c). (G) The specific staining of the Hla-b-associated transcript was found in the head region, including the optic lobes, at stage 22. (A), stage 20. (B), (G), stage 22. (C), (D), (E), (F), stage 25. Bar = 100 μm in (A)-(C), (F), (G); 50 μm in (D), (E).
Yoshida and Ogura BMC Evolutionary Biology 2011 11:180 doi:10.1186/1471-2148-11-180