Imaki H, Chavin W
Cell Tissue Res. 1975;158(3):363-73. doi: 10.1007/BF00223833.
The integumental melanophores of Australina lungfish, Neoceratodus forsteri, were examined by light and electron microscopy and found to possess essentially the same structural characteristics observed in other vertebrates. The epidermal melanophores are located in the intermediate epidermis and possess round perikarya and slender dendrites extending into nearby intercellular spaces. The dermal melanophores are found immediately below the basement membrane as well as in the deeper dermis. These cells possess flattened nuclei and dendrites running parallel to the basement membrane. Each melanophore contains numerous oval or elliptical, intensely electron-dense melanosomes, relatively large mitochondria, systems of vacuolar endoplasmic reticulum, groups of free RNP particles, and some microfilaments. Only a few, short microtubules could be demonstrated in the perinuclear cytoplasm of the dermal melanophore, while a relatively large number of late premelanosomes are found both in perikarya and dendritic processes of epidermal melanophores. These premelanosomes exhibit a particulate internal structure in cross section. Both melanosomes and premelanosomes occur singly in the cytoplasm of epidermal cells, thereby confirming the existence of the epidermal melanin unit in the lowest vertebrates thus far examined electron microscopically.
利用光学显微镜和电子显微镜对澳大利亚肺鱼（Neoceratodus forsteri）的体表黑素细胞进行了检查，发现其具有与其他脊椎动物基本相同的结构特征。表皮黑素细胞位于表皮中层，具有圆形的细胞体和延伸至附近细胞间隙的细长树突。真皮黑素细胞位于基底膜下方以及真皮深层。这些细胞具有扁平的细胞核和与基底膜平行的树突。每个黑素细胞包含许多椭圆形或椭圆形的、电子密度极高的黑素体、相对较大的线粒体、泡状内质网系统、游离核糖核蛋白颗粒群以及一些微丝。在真皮黑素细胞的核周细胞质中仅能观察到少数短微管，而在表皮黑素细胞的细胞体和树突状突起中均发现了相对大量的晚期前黑素体。这些前黑素体在横切面上呈现出颗粒状内部结构。黑素体和前黑素体在表皮细胞的细胞质中均单独存在，从而证实了在迄今为止通过电子显微镜检查过的最低等脊椎动物中存在表皮黑素单位。
