Boissy R E, Moellmann G, Trainer A T, Smyth J R, Lerner A B
J Invest Dermatol. 1986 Feb;86(2):149-56. doi: 10.1111/1523-1747.ep12284190.
Chickens of the autoimmune delayed-amelanotic (DAM or Smyth) line develop postnatal feather amelanosis and severe visual defects, both of which are presumed to be due to a dysfunction of melanocytes and a subsequent autoimmune response that eliminates pigment cells. In this report we elucidate further the melanocytic defect. We present a morphologic analysis of the mildly affected erratic (eDAM) group of Smyth chicken whose partial depigmentation and lack of visual impairment resemble human vitiligo more so than do the complete amelanosis and blindness in the classical Smyth line. Histologically, the sequential events leading to amelanosis in the young Smyth chicken occur simultaneously in the feathers of adult eDAM Smyth chickens, and the infiltration of the feather pulp with mononuclear leukocytes correlates with the extent of local pigmentary abnormality. Cytochemical localizations of dopa-oxidase and acid-phosphatase activities in eDAM feather melanocytes suggest that melanogenesis and autophagocytosis of melanosomes occur in tandem and that the rates of both are higher in these cells than in melanocytes of normally pigmented control chickens. Assays for tyrosinase activity in feather follicles indicate a hypermelanization in eDAM feathers and in the pigmented feathers of young Smyth chicks prior to the onset of depigmentation. Finally, we report on the establishment of pure, proliferative cultures of neural crest-derived melanocytes from control and Smyth chicken embryos. The degenerative events in Smyth chicken melanocyte cultures mimic in part those of the cells in vivo and are therefore indicative of a genetic defect that is independent of the immune system.
自身免疫性迟发性无黑色素（DAM或Smyth）品系的鸡在出生后会出现羽毛无黑色素沉着和严重的视觉缺陷，这两者据推测是由于黑素细胞功能障碍以及随后消除色素细胞的自身免疫反应所致。在本报告中，我们进一步阐明了黑素细胞缺陷。我们对Smyth鸡的轻度受影响的不稳定（eDAM）组进行了形态学分析，该组鸡的部分色素脱失和无视觉障碍比经典Smyth品系的完全无黑色素沉着和失明更类似于人类白癜风。组织学上，导致年轻Smyth鸡无黑色素沉着的一系列事件在成年eDAM Smyth鸡的羽毛中同时发生，单核白细胞对羽毛髓质的浸润与局部色素异常的程度相关。eDAM羽毛黑素细胞中多巴氧化酶和酸性磷酸酶活性的细胞化学定位表明，黑素生成和黑素小体的自噬作用同时发生，并且这些细胞中两者的速率均高于正常色素沉着对照鸡的黑素细胞。对毛囊中酪氨酸酶活性的测定表明，在色素脱失开始之前，eDAM羽毛和年轻Smyth雏鸡的色素沉着羽毛中存在黑素沉着过度。最后，我们报告了从对照和Smyth鸡胚胎中建立神经嵴衍生黑素细胞的纯增殖培养物。Smyth鸡黑素细胞培养物中的退化事件部分模拟了体内细胞的退化事件，因此表明存在与免疫系统无关的遗传缺陷。
