WNT (see MIM 604663) proteins are extracellular signaling molecules involved in the control of embryonic development. They may also contribute to neoplastic processes. There are at least 2 families of secreted inhibitors of WNT signaling: the secreted frizzled-related protein family (e.g., SFRP1; MIM 604156), all of which have an N-terminal cysteine-rich domain and are transmembrane receptors, and the Dickkopf (German for 'big head,' or 'stubborn') family.
NCBI Summary:
This gene encodes a protein that is a member of the dickkopf family. It is a secreted protein with two cysteine rich regions and is involved in embryonic development through its inhibition of the WNT signaling pathway. Elevated levels of DKK1 in bone marrow plasma and peripheral blood is associated with the presence of osteolytic bone lesions in patients with multiple myeloma. [provided by RefSeq, Jul 2008]
General function
Ligand, Growth factor
Comment
Cellular localization
Secreted
Comment
Ovarian function
Oocyte maturation
Comment
Dickkopf-Related Protein 1 Inhibits the WNT Signaling Pathway and Improves Pig Oocyte Maturation. Spate LD 2014 et al.
The ability to mature oocytes in vitro provides a tool for creating embryos by parthenogenesis, fertilization, and cloning. Unfortunately the quality of oocytes matured in vitro falls behind that of in vivo matured oocytes. To address this difference, transcriptional profiling by deep sequencing was conducted on pig oocytes that were either matured in vitro or in vivo. Alignment of over 18 million reads identified 1,316 transcripts that were differentially represented. One pathway that was overrepresented in the oocytes matured in vitro was for Wingless-type MMTV integration site (WNT) signaling. In an attempt to inhibit the WNT pathway, Dickkopf-related protein 1 was added to the in vitro maturation medium. Addition of Dickkopf-related protein 1 improved the percentage of oocytes that matured to the metaphase II stage, increased the number of nuclei in the resulting blastocyst stage embryos, and reduced the amount of disheveled segment polarity protein 1 protein in oocytes. It is concluded that transcriptional profiling is a powerful method for detecting differences between in vitro and in vivo matured oocytes, and that the WNT signaling pathway is important for proper oocyte maturation.
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