Molecular Characteristics and Site Specific Distribution of the Pigment of the Silky Fowl.

Abstract

ABSTRACT. Silky fowl, a breed of chicken, is hyperpigmented in its various internal tissues. The pigment was extracted from various tissues of two strains of Silky fowl to determine its molecular structure and internal distribution. Analysis by infrared spectroscopy showed two spectrum patterns of the pigment in Silky fowl; one is from ovary and testis, the other is from periosteum and feather. The difference between the two spectra is possibly due to the sulfur contents of melanin. Especially, the spectra of the pigments from feather and periosteum shared the characteristics of synthesized melanin spectrum in common, which indicates that the melanocytes dispersed in these tissues were functionally the same. According to our quantitative analysis, the tissues examined were classified significantly in the order of the pigment content (p<0.05): periosteum > gonads (ovary or testis) = trachea ≥ heart, liver, gizzard, cecum, muscles (Pectoralis and Supracoracoideus) and skin. In addition, the specific regions of embryonic neural crest derived cells, such as cardiac artery and various parts of cephalic tissues, were found to be locally hyperpigmented. These data suggest that hyperpigmentation (fibromelanosis) in Silky fowl chicken occurs in a tissue-and organ-specific manner, which is strongly related to neural crest cell development. It is hypothesized that neural crest cells of the bird, containing melanocyte progenitors, acquire unusual ability to differentiate into melanocytes excessively, and to extend the distribution of their descendant along the destinations of neural crest derivatives.-KEY WORDS: hyperpigmentation, melanocyte, neural crest, pigment distribution, Silky fowl.

Gene Duplication of endothelin 3 Is Closely Correlated with the Hyperpigmentation of the Internal Organs (Fibromelanosis) in Silky Chickens

“…On the pigmentation in dermal tissues of Silky chickens, common melanin was identified as the main pigment substance, and its chemical, physical, and morphological properties were similar to those in other breeds (Muroya et al 2000;Chen et al 2008). Cells having melanosomes in internal organs in Silky contain various stages of immature melanosomes in their cell bodies (Reedy et al 1998;Faraco et al 2001;Ortolani-Machado et al 2007, indicating that melanization occurs inside these cells.…”

“…Silky melanoblasts migrate through an unusual ventral pathway with other neural crest derivatives in addition to the common dorsolateral route and proliferate actively during migration (Hallet and Ferrand 1984;Erickson 1993;Lecoin et al 1995;Reedy et al 1998;Muroya et al 2000;Faraco et al 2001;Jacobs-Cohen et al 2002;Le Douarin and Kalcheim 2009). These melanoblasts invade the internal organs and settle among the connective tissues in a similar fashion to fibroblasts.…”

A microarray study of altered gene expression during melanoblasts migration in normal pigmented White Leghorn and hyperpigmented mutant Silky Fowl

“…The thoracic region of the chicken embryo is an important target for studying the mechanism of melanocyte development and most of the research findings for melanocyte development come from the studies at the thoracic level in avian embryos [11,12]. Melanocyte development depends on precise temporal and spatial gene regulation during embryogenesis.…”

“…As a natural mutant breed, SF shows extensive pigmentation, including periosteum, gonads, trachea, heart, liver, gizzard, cecum, perimysium and many other organs [11]. This rare and extensive hyperpigmentation in SF compared to the other higher vertebrates, provides us a very appropriate natural mutant model to investigate the mechanism of gene regulation during melanocyte development.…”

Transcriptome Profile Analysis of Mechanisms of Black and White Plumage Determination in Black-Bone Chicken

“…However, some individuals have black skin and white plumage; such that they differ from normal chickens only in their plumage colour. Black-bone chickens are hyperpigmented in various tissues, including the skin, muscle, ovary, and periosteum [14]. The special trait of hypermelanic pigmentation in the silky breed is due to dermal melanin and is independent of feather colour, as several varieties of this breed are described as having black skin and variable plumage colour: white, black, or gold [15].…”