Background The origin of birds is one of the most enduring and dramatic evolutionary
debates. The hypothesis that the primarily small-sized birds are nested within a theropod …

The aim of this study was to evaluate the distribution of inhibin/activin alpha, beta (A) and
beta (B) subunits and follistatin in immature oocytes and in matured oocytes before and after …

The first comprehensive review of all aspects of the biology of moult, drawing information
from across the literature and in all birds, from penguins to passerines. Feathers are …

We expose it, cover it, paint it, tattoo it, scar it, and pierce it. Our intimate connection with the
world, skin protects us while advertising our health, our identity, and our individuality. This …

During embryogenesis, stem cells are set aside to fuel the postnatal hair cycle and repair the
epidermis after injury. To define how hair follicle stem cells are specified and maintained in …

Developmental biology research has used various avian species as model organisms for
studying morphogenesis, with the chick embryo being used by the majority of groups. The …

Parrot feathers contain red, orange, and yellow polyene pigments called psittacofulvins.
Budgerigars are parrots that have been extensively bred for plumage traits during the last …

Epithelial stem cells reside in specific niches that regulate their self-renewal and
differentiation, and are responsible for the continuous regeneration of tissues such as hair …

Tumor formation involves substantial cell division and genetic instability, but the relationship
between quiescent cancer stem cells (CSC) and dividing progenitors in these events is …

The mammalian epidermis is a highly accessible tissue in which to study the properties of
adult stem cells. Global gene expression profiling has revealed new markers and regulators …