Your Inner Fish

Zone of Polarizing Activity (ZPA) Term Analysis

The small zone at the extreme end of an embryo’s limb bud, where all of the activity of building the limb takes place.
Get the entire Your Inner Fish LitChart as a printable PDF.
Your inner fish.pdf.medium

Zone of Polarizing Activity (ZPA) Term Timeline in Your Inner Fish

The timeline below shows where the term Zone of Polarizing Activity (ZPA) appears in Your Inner Fish. The colored dots and icons indicate which themes are associated with that appearance.
Chapter 3: Handy Genes
Understanding Complex Concepts Through Simple Analogies Theme Icon
Scientific Discovery Theme Icon
...The patch of tissue that controls limb development was named the zone of polarizing activity (ZPA). (full context)
Understanding Complex Concepts Through Simple Analogies Theme Icon
The ZPA controls the formation of fingers and toes by controlling the concentration (amount) of a certain... (full context)
Similarities Between All Animals Theme Icon
...In the 1990s, scientists were better able to look for the molecular mechanisms that the ZPA uses to differentiate fingers. Cliff Tabin, Andy MacMahon, and Phil Ingham decided to look at... (full context)
Similarities Between All Animals Theme Icon
History of Life  Theme Icon
...“sonic hedgehog” (named after the video game character). Sonic hedgehog is only active in the ZPA of chicken embryo limbs. After experiments that confirmed that hedgehog does the same limb production... (full context)
Similarities Between All Animals Theme Icon
Scientific Discovery Theme Icon
...as chicken limbs – to the point of producing a duplicate fin when the shark ZPA was treated with Vitamin A. (full context)
Similarities Between All Animals Theme Icon
History of Life  Theme Icon
Dahn went further to see if the shark ZPA could be influenced with the protein that the sonic hedgehog gene produces in mice. Normally,... (full context)