The apical ectodermal ridge is a thickened epithelium at the most distal end of the limb bud. The zone of polarizing activity is at the posterior part of the limb bud.
Details
Identifiers
Latin
zona activitatis polarisantis
Acronym(s)
ZPA
TE
of polarizing activity_by_E5.0.3.0.0.1.5 E5.0.3.0.0.1.5
Anatomical terminology
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The zone of polarizing activity (ZPA) is an area of mesenchyme that contains signals which instruct the developing limb bud to form along the anterior/posterior axis. Limb bud is undifferentiated mesenchyme enclosed by an ectoderm covering. Eventually, the limb bud develops into bones, tendons, muscles and joints. Limb bud development relies not only on the ZPA, but also many different genes, signals, and a unique region of ectoderm called the apical ectodermal ridge (AER). Research by Saunders and Gasseling in 1948 identified the AER and its subsequent involvement in proximal distal outgrowth.[1] Twenty years later, the same group did transplantation studies in chick limb bud and identified the ZPA. It wasn't until 1993 that Todt and Fallon showed that the AER and ZPA are dependent on each other.[2]
^Saunders JW (December 1998). "The proximo-distal sequence of origin of the parts of the chick wing and the role of the ectoderm. 1948". The Journal of Experimental Zoology. 282 (6): 628–68. doi:10.1002/(SICI)1097-010X(19981215)282:6<628::AID-JEZ2>3.0.CO;2-N. ISSN 0022-104X. PMID 9846378.
^Todt WL, Fallon JF (1 November 1987). "Posterior apical ectodermal ridge removal in the chick wing bud triggers a series of events resulting in defective anterior pattern formation". Development. 101 (3): 501–15. ISSN 0950-1991. PMID 3502993.
and 25 Related for: Zone of polarizing activity information
The zoneofpolarizingactivity (ZPA) is an area of mesenchyme that contains signals which instruct the developing limb bud to form along the anterior/posterior...
the zoneofpolarizingactivity (ZPA) with the mesenchymal cells. In addition to the dorsal-ventral axis created by the ectodermal expression of competitive...
(AER) and the zoneofpolarizingactivity (ZPA) with the mesenchymal cells. These signaling centers are crucial to the proper formation of a limb that is...
expression of SHH is seen on the anterior side of the limb. Normally SHH is expressed in an organiser region, called the zoneofpolarizingactivity (ZPA)...
mesenchyme—including the zoneofpolarizingactivity (ZPA)—continue to communicate with each other to direct further limb development. The position of the limb bud...
digits depends on the secretion of sonic hedgehog by the zoneofpolarizingactivity, located on the posterior side of the embryonic limb bud. Mutations...
using chicken embryos, such as the discovery of the apical ectodermal ridge and the zoneofpolarizingactivity. The chicken was the first bird species to...
generation of the hand (digits - interdigits): the gradient of sonic hedgehog (secreted inducing factor) from the zoneofpolarizingactivity in the limb...
found in the zoneofpolarizingactivity regulatory sequence, or ZRS, that controls the expression of SHH in developing limbs. Many cases of polysyndactyly...
associated with DNA mutations in the ZoneofPolarizingActivity Regulatory Sequence (ZRS), a regulatory region of the sonic hedgehog gene which is critically...
1Mb upstream of SHH gene has been implicated. Normally SHH is expressed in an organiser region, called the zoneofpolarizingactivity (ZPA) on the posterior...
diffusible factor produced by the zone of polarizingactivity (ZPA), a small region of tissue at the posterior margin of the limb. Mammalian development appeared...
Ultimately, Tbx4 leads to the development of apical ectodermal ridge (AER) and zoneofpolarizingactivity (ZPA) signaling centers in the developing limb...
Under the AEC, the nerves near the site of the limb destroyed are degraded. The AEC causes the progress zone to re-establish; this means the cells under...
morphogenesis of limb buds have been focused on one particular axis of limb bud. However it has long been noted that zoneofpolarizingactivity (ZPA) requires...
patterning of these regions. The Zoneofpolarizingactivity (ZPA) in the limb bud has pattern-organizing activity through the utilization of a morphogen...
the expression of Sonic Hedgehog (SHh) to the posterior mesenchyme, which will eventually give rise to the ZoneofPolarizingActivity (ZPA). This gene...
(shh) signaling in the limb buds of embryos. The zoneofpolarizingactivity (ZPA) in the proximal posterior mesoderm of a tetrapod limb bud is responsible...
an important role in the development or outgrowth of a limb along with the zoneofpolarizingactivity(ZPA). Using these findings, Tickle focused her research...
regions of the germinal center: the light zone (LZ) and the dark zone (DZ). These two zones are formed from pre-GC B cells that proliferate and polarize seven...
within the convective zoneof the star. The convective circulation of the conducting plasma functions like a dynamo. This activity destroys the star's primordial...
periphery of the ruffled border is surrounded by a ring-like zoneof cytoplasm which is devoid of cell organelles but is rich in actin filaments. This zone is...
Retrieved 10 April 2024. Luria, S. M.; Kinney, J. A. (December 1974). "Linear polarizing filters and underwater vision". Undersea Biomedical Research. 1 (4): 371–8...
automatically schedules the activity at optimal times. Google Calendar's mobile apps have received polarized reviews. 2015 reviews of the Android and iOS apps...
liver lobules. Cells in the periportal zone are directly exposed to bloodflow, and express greater lysosomal activity to more efficiently process incoming...
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