Prenatal feather growth development in the chicken was studied in 7 body regions in HH stages 27-45, using direct measurements, specific histological and immunohistochemical methods, and scanning electron microscopy. The results from measurements of absolute length values, and, particularly, growth rate development in each HH stage revealed a distinct phase of most intensive growth in HH stage ...

Feather mites are a diverse group of ectosymbionts that occur on most species of birds. Although Darwin's finches are a well-studied group of birds, relatively little is known about their feather mites. Nearly 200 birds across 9 finch species, and from 2 locations on Santa Cruz Island, Galápagos, were dust-ruffled during the 2009 breeding season. We found 8 genera of feather mites; the most pre...

BACKGROUND The plumage of birds is important for flying, insulation and social communication. Contour feathers cover most of the avian body and among other functions they provide a critical insulation layer against heat loss. Feather structure and composition are known to vary among individuals, which in turn determines variation in the insulation properties of the feather. However, the extent ...

Operational discharges of hydrocarbons from maritime activities can have major cumulative impacts on marine ecosystems. Small quantities of oil (i.e., 10 ml) results in often lethally reduced thermoregulation in seabirds. Thin sheens of oil and drilling fluids form around offshore petroleum production structures from currently permissible operational discharges of hydrocarbons. Methodology was ...

Bone morphogenetic protein (BMP) signaling is known to be involved in multiple inductive events during embryogenesis including the development of amniote skin. Here, we demonstrate that early application of BMP-2 to the lateral trunk of chick embryos induces the formation of dense dermis, which is competent to participate in feather development. We show that BMPs induce the dermis markers Msx-1...

Nanocrystalline Al–Mg dendrites were fabricated through galvanostatic electrodeposition. Initially feather-like morphology was formed exhibiting morphological evolution to smooth globules at its tips. With eventual deposition, rough globules formed over the smooth ones. The feather-like and smooth globules possessed supersaturated face centered cubic (fcc)–Al(Mg) phase with ~7 and ~20 at.% Mg r...

creating the hair. FGFs, BMPs, and Shh are secreted proteins whose binding to receptors on susceptible cells triggers signal transduction changes and transcription Hairs in mammals and feathers in birds are two of the of target genes. Notch receptor, in contrast, is activated smallest and most fascinating organs in the body. These by membrane-bound ligands such as Delta-1 on the keratinized ski...

Figure 9 summarizes the morphogenetic process of feather and hair. Hair of feathers are formed from a layer of homogeneously distributed mesenchymal cells. The mesenchymal cells start to condense to form foci in response to some unidentified induction signal (Fig. 9B). Several adhesion molecules, including L-CAM, N-CAM, integrin, tenascin, as well as proteoglycan, are involved. These adhesion m...