XB-IMG-172242
Xenbase Image ID: 172242
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Figure 6. Injection of mRNA Encoding Short XlHbox 1 Protein Changes the Morphology of Anterior Spinal Cord to That of Hindbrain
(Top row) Control 3-day-old tadpole injected with mutant short XlHbox l/pro45 mRNA. Uninjected control tadpoles were identical. (Bottom row) Sibling
3-day-old tadpole injected with short XlHbox 1 protein mRNA.
(A, A) Tadpoles were immunostained in whole mount with XlHbox 6 antibody and viewed dorsally. Specific nuclear staining is observed in the CNS,
which runs horizontally from hindbrain to spinal cord, with XlHbox 6 staining beginning just ahead of arrow B or B’. XlHbox 6 is found in the spinal
cord of the control tadpole, but in tadpoles showing cervical spinal cord malformations, XlHbox 6 is expressed in the new hindbrain-like region as
well as the more posterior normal spinal cord. The unstained pronephri appear symmetrically as two darkened regions on each side of the control
tadpole, but were accidentally removed together with the endoderm from the embryo injected with wild-type mRNA. The phenotype was analyzed
further by serial sectioning and immunostaining with antibodies specific for XlHbox 1 and XlHbox 6.
(B-D; S-D’) Transverse sections taken at the levels indicated by the arrows in (A) and (A)‘, respectively. All sections were immunostained with XlHbox
6 antibody, with positive nuclei appearing as black dots within the CNS. Comparison of the two rows of photographs shows that the affected cervical
region resembles hindbrain rather than spinal cord, and expresses the spinal cord-specific XlHbox 6 protein over the normal anteroposterior limits.
The alteration shown here extends more posteriorly than that seen in the long XlHbox l-Ab injection experiments. Abbreviations: HB, hindbrain;
IV, hindbrain cavity called the fourth ventricle; SC, spinal cord. Image published in: Wright CV et al. (1989) Copyright © 1989. Image reproduced with permission of the Publisher, Elsevier B. V. Larger Image Printer Friendly View |