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Fig. 1. Whole-mount in situ hybridization of Xlim-1 RNA.
(A) Dorsal view of a stage 12 embryo (late gastrula). Anterior side
(An) is top. Staining is detected in the prechordal mesoderm (pm)
and forming notochord (n). Dark staining at the lateral to ventral
edge is due to accumulated background. (B) Stage 12.5. The
notochord is stained. Signal also appears in lateral mesoderm (black
arrows) and in neural ectoderm (white arrows); the distinction
between these regions is more clearly seen in Fig. 3G.
(C) Ventrolateral view of stage 14 embryo showing that the staining
in the lateral mesoderm forms a broad stripe. (D) Dorsal view of
stage 14 (neural plate) embryo. Two lines of neural expression
(white arrow, right only) are visible, which are now separated from
the underlying mesoderm staining (black arrow). Notochord staining
has diminished. (E) Dorsal view of stage 15/16 (neural fold) embryo.
The two lines of neural expression expand anteriorly, and notochord
staining disappears from the anterior part. (F) Stage 17/18. Neural
expression expands posteriorly, while notochord staining disappears,
except in the posterior tip. Lateral staining concentrates in the dorsal
region (black arrow). (G) Anterior views with the plane of focus in
the middle of the embryos at stages 14 (top panel), 15 (middle), and
16 (bottom). During the formation of the neural tube, staining is
restricted to the deep layer. (H) Anterodorsal view of a stage 22
embryo. Pronephros (p) is stained. Neural expression is located in
the hindbrain and spinal cord. Hindbrain staining is interrupted at the
level of the otic vesicle, corresponding to rhombomere 4 (small
white arrow). (I) Lateral view of head region of the same embryo as
in H. A small white arrow indicates the gap of expression in the
hindbrain. Weak staining occurs in the midbrain (open arrow).
(J) Cross section of embryo at stage 28 (stained before sectioning)
showing staining of the pronephros and lateral region of spinal cord.
(K) Lateral view of stage 26 embryo. The expression in the midbrain
is enhanced compared to that in I (open arrow). The gap of
expression in the hindbrain becomes narrow (white arrow). The
pronephros and pronephric duct on both sides are strongly positive.
The posterior tip of notochord is still stained (arrow). (L) Lateral
view of the tail bud region at stage 31, showing staining in the
posterior tip of the notochord (arrow). An, anterior; n, notochord; p,
pronephros; pm, prechordal mesoderm; s, somite. |
