ZFIN ID: ZDB-FIG-080515-3
Winkler et al., 2001 - Zebrafish mdk2, a novel secreted midkine, participates in posterior neurogenesis. Developmental Biology   229(1):102-118 Full text @ Dev. Biol.
Anatomical Terms:
Stage Range: 4-cell to Prim-5

Fig. 2 Expression of mdk2 during zebrafish embryogenesis. (A) RT-PCR of different embryonic stages. β-catenin was used as loading control. (B–N) RNA whole-mount in situ hybridization using full-length mdk2 as probe. (B) 60% epiboly (lateral view, dorsal to the right). Onset of mdk2 expression in the epiblast in a region overlaying the involuting hypoblast (arrows). (C) Close-up of shield region as in B. Arrow indicates anterior border of mdk2 expression overlaying the anterior edge of involuting mesendoderm. (D) 70% epiboly. Expression throughout the presumptive neural plate. Arrow indicates leading edge of axial hypoblast. (E) Optical section through embryo at 70% epiboly at the level of shield region (dorsal to the right). Dorsoventral gradient of mdk2 expression in the epiblast. (F) Higher magnification of shield region (as boxed in E). mdk2 transcripts are excluded from the involuting mesendoderm. (G) 80% epiboly, dorsal view, anterior to the left. Regionalization of mdk2 expression in the early neural plate. Arrowhead indicates elevated expression at the prospective mid–hindbrain boundary (MHB). Arrows demarcate expression at lateral edges of the neural plate. (H) 90% epiboly, dorsal view. Double labeling with eng2 (in red) demarcating future MHB (arrowheads). Arrows indicate mdk2 expression at the edges of the posterior neural plate. (I) Higher magnification of MHB region as in H showing overlapping expression of mdk2 (blue) and eng2 (red). (J) Bud stage, dorsal view. Arrowhead indicates future MHB, arrows denote expression at the edges of the forming neural keel. (K) Lateral view of embryo in J. Arrows mark the developing hindbrain exhibiting a gradient of mdk2 expression with its maximum at the anterior end. Arrowhead indicates strong mdk2 expression at the MHB. (L) 12-h embryo, dorsal view of head region. mdk2 is expressed in the diencephalon (arrow), at the MHB (arrowhead), and in a gradient in the hindbrain, but excluded from the eye fields and midbrain. (M) 12-h embryo, dorsal view of MHB region. Double labeling with eng2 (red). eng2 is expressed across the MHB (bracket), whereas mdk2 marks the anteriormost edge of the metencephalon (arrow). (N) 14-h embryo, lateral view. mdk2 expression at the MHB (arrowhead), in the dorsal neural tube (small arrows), and in dissociating prechordal plate cells underneath the forebrain (large arrows). (O) Frontal view of head region as in N. Arrows indicate dissociating prechordal plate. (P) Latemdk2 expression in fore- and dorsal midbrain, MHB (arrowhead), hindbrain, and dorsal neural tube (arrows).

Gene Expression Details
Gene Antibody Fish Conditions Stage Qualifier Anatomy Assay
mdkb WT standard conditions 4-cell to 8-cell Not Detected whole organism RTPCR
Sphere Not Detected whole organism RTPCR
Shield epiblast ISH
Shield presumptive neural plate ISH
Shield whole organism RTPCR
75%-epiboly presumptive midbrain hindbrain boundary ISH
75%-epiboly presumptive neural plate ISH
75%-epiboly to 90%-epiboly whole organism RTPCR
90%-epiboly midbrain hindbrain boundary neural plate ISH
90%-epiboly neural plate ISH
Bud hindbrain neural keel ISH
Bud midbrain hindbrain boundary neural keel ISH
Bud neural keel ISH
5-9 somites hindbrain neural rod ISH
5-9 somites midbrain hindbrain boundary neural rod ISH
5-9 somites Not Detected midbrain neural rod ISH
5-9 somites Not Detected optic vesicle ISH
5-9 somites presumptive diencephalon ISH
5-9 somites whole organism RTPCR
10-13 somites midbrain hindbrain boundary neural rod ISH
10-13 somites prechordal plate ISH
10-13 somites spinal cord neural rod dorsal region ISH
Prim-5 whole organism RTPCR
Antibody Labeling Details No data available
Phenotype Details No data available
ZFIN wishes to thank the journal Developmental Biology for permission to reproduce figures from this article. Please note that this material may be protected by copyright.

Reprinted from Developmental Biology, 229(1), Winkler, C. and Moon, R.T., Zebrafish mdk2, a novel secreted midkine, participates in posterior neurogenesis, 102-118, Copyright (2001) with permission from Elsevier. Full text @ Dev. Biol.