Skin development in bony fish with particular emphasis on collagen deposition in the dermis of the zebrafish (Danio rerio).

Analysis of axis induction mutant embryos reveals morphogenetic events associated with zebrafish yolk extension formation

“…These migrating cells appear in a focal plane that is more internal than that corresponding to the flattened, surface cells that likely belong to the enveloping cell layer (EVL; Fig. 3t-bb, we refer to the outermost cell layer in the yolk cell as the EVL, although the term "periderm" has also been used at these stages of development; Le Guellec et al, 2004). Thus, the anteriorly directed migratory movement of tail bud-derived cells appears to occur in the space between the yolk syncytial layer (YSL) and the EVL.…”

Epidermal transient down‐regulation of retinol‐binding protein 4 and mirror expression of apolipoprotein Eb and estrogen receptor 2a during zebrafish fin and scale development

“…Consequently, the transient down-regulation of rbp4 in epidermal cells occurs according to a restrictive mode of molecular expression and does not appear to play a role in the early specification or positioning of the placodes, but rather to be a downstream responsive early element in the inducible wave of epidermal placode formation. Morphological studies have revealed that scale formation takes place in the dermis after condensation below the epidermal basement membrane of a scale dermal papilla from invading fibroblast-like cells, by around 1 month postfertilization (Le Guellec et al, 2004;Sire and Akimenko, 2004). Each scale-forming cell population in a scale papilla gives rise to a single scale.…”

“…In vertebrates, the skin consists of an epithelial epidermis of ectodermal origin, consisting of a stratified, squamous epithelium resting on a basal lamina of fibrils and overlying a dermis of fibrous connective tissue. Numerous studies have focused on the histology and cytochemistry of the skin of teleost fish species at embryo/larva stage, including zebrafish (Danio rerio; reviewed in Le Guellec et al, 2004), and adult stages (reviewed in Whitear, 1986). In these aquatic animals, the epidermis is mainly composed of squamous epidermal and mucous cells, covered with a mucous layer.…”

“…At this stage, the underlying developing skin is very thin and, by 1 day postfertilization (dpf), it starts to differentiate (Le Guellec et al, 2004). The epidermis consists of two cell layers, a structure conserved until the larval stages, and the cells of the upper layer are ornamented with short microridges.…”

“…Apart from its protective role, the thin skin of newly hatched teleost larva is involved in osmoregulation, respiration, and excretion (reviewed in Varsamos et al, 2005). Thickening of the primary dermal stroma underlying the epidermis occurs during larval stages, and there is a remarkable remodeling and thickening of the larval skin during the larval-to-juvenile transition (Le Guellec et al, 2004). This metamorphosis entails changes in a variety of organ systems, including resorption of the larval fin fold and development of adult unpaired fins, development of scales in the integument, and formation of an adult pigment pattern (Brown, 1997;Sire et al, 1997a).…”