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The Wnt signaling pathway is a conserved pathway. The Wnt family of signaling proteins participates in multiple developmental events during embryogenesis and has also been implicated in adult tissue homeostasis. Wnt signals are pleiotropic, with effects that include mitogenic stimulation, cell fate speciï¬cation, and differentiation. The Wnt signaling pathway is an ancient and evolutionarily conserved pathway that regulates crucial aspects of cell fate determination, cell migration, cell polarity, neural patterning and organogenesis during embryonic development.
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Wnt Signaling Pathway What is Wnt? The term “Wnt” is derived from the terms wingless and int. The Int oncogenes, including Int1, were first identified in the mouse mammary tumor. In 1987, investigators sequenced wingless in Drosophila and found it was the homolog of int-1. Thus, the int/Wingless family became the Wnt family and int1 became Wnt1. The name Wnt is a portmanteau of int and Wg and stands for "Wingless-related integration site". Wnts are secreted factors that regulate cell growth, motility, and di during embryonic development. Wnts act in a paracrine fashion by activating diverse signaling cascades inside the target cells. erentiation Wnt gene family The Wnt family consists of a number of highly conserved genes that regulate gene expression, cell behavior, cell adhesion, and cell polarity, including 19 genes in humans and mice, 7 in Drosophila, and 5 in C. elegans. Wnt-1 is one member of a gene family whose additional members were isolated either as a target for MMTV insertion (Wnt-3, Wnt-3A was subsequently isolated by homology to Wnt-3), fortuitously from a chromosomal walk directed around the cystic fibrosis gene (Wnt-2), or from mouse embryo RNA using the polymerase chain reaction (Wnt-4, -5A, -5B, -6, -7A,and -7B) . There are now at least 10 known members of the Wnt family in the mouse; all of which are expressed during development, many in the developing nervous system with some expressed in adult brain as well. In addition, five members of the Wnt family are expressed in the normal mammary gland in the mouse and are differentially regulated during pregnancy and lactation. This family has been remarkably well conserved throughout evolution, with homologues present in both invertebrates and vertebrates. In addition to the predicted amino acid sequence similarities among family members, a role in cell signaling has also been documented for several Wnt family members. For example, wingless, the Drosophila homologue of Wnt-1, is necessary for proper segmental patterning of the embryo and is proposed to function locally via cell-cell interactions. http://www.creative-diagnostics.com/wnt-signaling-pathway.htm
