title: Cell tracing reveals a dorsoventral lineage restriction plane in the mouse limb bud mesenchyme.
abstract: Regionalization of embryonic fields into independent units of growth and patterning is a widespread strategy during metazoan development. Compartments represent a particular instance of this regionalization, in which unit coherence is maintained by cell lineage restriction between adjacent regions. Lineage compartments have been described during insect and vertebrate development. Two common characteristics of the compartments described so far are their occurrence in epithelial structures and the presence of signaling regions at compartment borders. Whereas Drosophila compartmental organization represents a background subdivision of embryonic fields that is not necessarily related to anatomical structures, vertebrate compartment borders described thus far coincide with, or anticipate, anatomical or cell-type discontinuities. Here, we describe a general method for clonal analysis in the mouse and use it to determine the topology of clone distribution along the three limb axes. We identify a lineage restriction boundary at the limb mesenchyme dorsoventral border that is unrelated to any anatomical discontinuity, and whose lineage restriction border is not obviously associated with any signaling center. This restriction is the first example in vertebrates of a mechanism of primordium subdivision unrelated to anatomical boundaries. Furthermore, this is the first lineage compartment described within a mesenchymal structure in any organism, suggesting that lineage restrictions are fundamental not only for epithelial structures, but also for mesenchymal field patterning. No lineage compartmentalization was found along the proximodistal or anteroposterior axes, indicating that patterning along these axes does not involve restriction of cell dispersion at specific axial positions.
authors: Departamento de Biología del Desarrollo Cardiovascular, Centro Nacional de Investigaciones Cardiovasculares, Instituto de Salud Carlos III, E-28029 Madrid, Spain.
authors: Carlos G
authors: CG
authors: Arques
authors: Roisin
authors: R
authors: Doohan
authors: James
authors: J
authors: Sharpe
authors: Miguel
authors: M
authors: Torres
mesh_terms: D000818:Animals; D019521:Body Patterning; D019070:Cell Lineage; D004622:Embryo, Mammalian / Q000033:anatomy & histology / Q000502:physiology; D005260:Female; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D060850:LIM-Homeodomain Proteins; D018878:Limb Buds / Q000033:anatomy & histology / Q000196:embryology; D008297:Male; D008648:Mesoderm / Q000166:cytology / Q000196:embryology; D051379:Mice; D008822:Mice, Transgenic; D011247:Pregnancy; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D018398:Homeodomain Proteins; C112149:LIM homeobox transcription factor 1 beta; D060850:LIM-Homeodomain Proteins; D014157:Transcription Factors