Melanogenesis is the unique process of producing the melanin within melanosomes
and is a major function of both differentiated normal melanocytes and malignant melanoma cells .
The skin contains ABC transporters, responsible for molecular transportation across cell membranes, which play roles in melanosome
transport to surrounding keratinocytes .
Since norepinephrine (NE) could induced melanosome
aggregation in fish scales [11,12,30], parallel treatment with NE was used as a positive control for pigment aggregation.
Theconstitutive skin pigmentation is regulated by a number of factors including the relative amounts of eumelanin (brown- black pigment) and pheomelanin (red-yellow pigment) synthesized within melanosomes
melanocyte dendricity transport of melanosomes
to dendrites and the rate of melanosome
transfer to the surrounding keratinocytes (Abdel-Malek and Kadekaro2006).It is also reported that autophagy plays a role in skin colour in humans by regulating melanosome
degradation in keratinocytes and thereby contributes to the ethnic diversity of skin color (Murase et al.
The evolution of diverse melanosomes
in these organisms raises the possibility that melanosome
shape and size could yield insights into dinosaur physiology.
This phenomenon, referred to as "melanosome
hijacking", has already been described for varicella-zoster virus, another herpesvirus that displays tropism for human skin .
Melanin fills the melanosome
, which is transported to the dendrites of the melanocyte and is eventually transferred to the keratinocytes where it forms a nuclear cap that protects DNA from UV-induced damage.
(4) Diagnosis can be made if the lesion is positive for antigens of melanosome
, such as protein S-100 and HMB45.
Moreover, autophagy activation promotes melanosome
degradation in keratinocytes.
Iris pigment dispersion and associated atrophy have also been observed in several other mouse models and causative genes together implicate melanosome
genes as playing a central role in iris pigment dispersion pathogenesis [77, 82-84].
That's when Vinther and colleagues proposed that microscopic structures in a roughly 125-million-year-old fossil feather were actually a type of melanosome
(SN: 8/2/08, p.10).
The antibodies tested were vimentin (dilution 1: 100); [alpha]-SMA (dilution 1: 200); desmin (dilution 1:100); myogenin (dilution 1:100); S-100 protein (dilution 1: 500); CD99 (dilution 1: 100); CD34 (dilution 1: 50); B-cell lymphoma 2 (Bcl-2) protein (dilution 1:100); CD10 (dilution 1: 200); CD117 (dilution 1: 400); cytokeratins (AE1/AE3 clone; dilution 1:50); epithelial membrane antigen (EMA) (dilution 1 : 100); anti-human melanosome
(HMB45) (dilution 1: 300), all from Dako, Glostrup, Denmark.