Progress zone

Progress zone is a term used in embryology to describe a region at the distal end of a developing limb bud where cells remain undifferentiated. The concept of the progress zone model was first proposed by Summerbell, Lewis, and Wolpert in 1973.

Etymology

The term "progress zone" was coined by Summerbell, Lewis, and Wolpert in their 1973 paper. The term is derived from the idea that this area of the limb bud is where progress is made in terms of cell differentiation and limb development.

Function

The progress zone plays a crucial role in limb development. Cells in the progress zone receive signals from the apical ectodermal ridge (AER), a thickened area of ectoderm at the tip of the limb bud. These signals keep the cells in the progress zone in an undifferentiated state. As cells leave the progress zone, they begin to differentiate and contribute to the formation of the limb's structures.

Related Terms

• Apical ectodermal ridge (AER): A thickened area of ectoderm at the tip of the limb bud that sends signals to the progress zone.
• Zone of polarizing activity (ZPA): A region in the posterior part of the limb bud that plays a role in anterior-posterior patterning.
• Retinoic acid: A signaling molecule that has been implicated in regulating progress zone activity.

See Also

• Limb development
• Embryology
• Cell differentiation

References

Progress zone Resources
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