Limb Bud Formation
Limb Bud Formation - Related Videos
00:49
The Tongue and Taste Buds
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2025
The surface of the tongue is covered with various small bumps called papillae, which either distribute what has been ingested (filiform papillae) or contain the sensory taste (or gustatory) receptor cells (fungiform, circumvallate, and foliate papillae). Embedded within each taste-related papilla are the taste buds—clusters of 30 to 100 gustatory receptor cells. Gustatory receptor cells extend finger-like projections called gustatory hairs (or microvilli) into a region known as the taste pore.
17:01
Acquiring Fluorescence Time-lapse Movies of Budding Yeast and Analyzing Single-cell Dynamics using GRAFTS
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Cited by 4 •
2013
We present a simple protocol to obtain fluorescence microscopy movies of growing yeast cells, and a GUI-based software package to extract single-cell time series data. The analysis includes automated lineage and division time assignment integrated with visual inspection and manual curation of tracked data.
08:48
Targeted in Situ Mutagenesis of Histone Genes in Budding Yeast
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Cited by 4 •
2017
A strategy for generating mutations in histone genes at their endogenous location in Saccharomyces cerevisiae is presented.
15:02
Analysis of the Development of a Morphological Phenotype as a Function of Protein Concentration in Budding Yeast
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Cited by 1 •
2010
Gene deletion and protein overexpression are common methods for studying functions of proteins. In this article, we describe a protocol for analysis of phenotype development as a function of protein concentration at population and single-cell levels in Saccharomyces cerevisiae.
04:24
Inhibition of Wound Epidermis Formation via Full Skin Flap Surgery During Axolotl Limb Regeneration
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Cited by 14 •
2020
This article describes how to perform a surgical method to inhibit wound epidermis formation during axolotl limb regeneration by immediately suturing full thickness skin over the amputation plane. This method allows researchers to investigate the functional roles of the wound epidermis during the early stages of limb regeneration.
FAQs
The apical ectodermal ridge, or AER, produces fibroblast growth factors that sustain continued limb outgrowth. Its signaling helps maintain the proliferative developmental environment established by interactions between ectoderm and lateral plate mesoderm. Because this support persists during early development, changes in AER activity can affect how far the developing limb extends and how later structures are established.
The zone of polarizing activity, or ZPA, uses Sonic hedgehog signaling to organize the limb along its anterior-posterior axis. This provides positional information rather than simply promoting growth, allowing developing tissues to acquire different locations within the limb. Studying this signaling system helps explain how an initially growing bud becomes spatially patterned for later skeletal and digit formation.
Signals from the lateral plate mesoderm and adjacent ectoderm work together to stimulate mesenchymal proliferation, creating the cellular basis for continued development. The ectoderm-associated apical ectodermal ridge then contributes fibroblast growth factor signals, while the zone of polarizing activity supplies Sonic hedgehog patterning information. Their cooperation links tissue growth with positional organization.
Growth and patterning represent related but distinct developmental functions. Fibroblast growth factors from the apical ectodermal ridge maintain outgrowth, whereas Sonic hedgehog signaling from the zone of polarizing activity establishes anterior-posterior organization. Considering these roles separately helps explain how the limb can both increase in size and assign positional information needed for skeletal and digit development.
Limb bud formation provides a developmental context for the later emergence of skeletal, muscle, connective tissue, and digit components. The coordinated signaling environment does not act on only one tissue type; it guides several lineages as the limb develops. Consequently, researchers can use this process to connect early embryonic signaling with the organization of multiple mature limb structures.
This process offers a model for examining how localized embryonic signals coordinate proliferation, outgrowth, and positional patterning. Its study clarifies broader principles of vertebrate development because several tissue types respond within one developing structure. It also connects molecular signaling, including fibroblast growth factors and Sonic hedgehog, with the organized formation of the vertebrate limb.
Because limb development depends on coordinated signals for outgrowth and anterior-posterior patterning, developmental disruption can be examined in relation to abnormal limb formation. Studying the apical ectodermal ridge, zone of polarizing activity, and their associated signals provides a framework for interpreting such abnormalities. The process therefore links embryological mechanisms with congenital differences affecting limb development.