Okumoto H, Nishioka M, Miura I, Obika M
Laboratory for Amphibian Biology, Faculty of Science, Hiroshima University, Higashihiroshima, Japan.
Pigment Cell Res. 1995 Aug;8(4):187-93. doi: 10.1111/j.1600-0749.1995.tb00662.x.
A cDNA encoding tyrosinase of Rana nigromaculata was introduced into cultured, tyrosinase-negative amelanotic melanophores of R. brevipoda by a calcium phosphate precipitation method. Within a few days following transfection, dark pigmentation became visible in a small number of cells. Light microscopic observation revealed that the morphology of these transformed cells was comparable to that of normal melanophores in culture, and their proliferative activity was lower than that of amelanotic cells. Ultrastructural examination verified that amelanotic melanophores possessed a relatively small number of premelanosomes while the transformants contained numerous melanosomes at various stages of pigment deposition. The result indicated that tyrosinase cDNA of R. nigromaculata was expressed in amelanotic melanophores of R. brevipoda including the maturation of premelanosomes. It was also suggested that the expression of transfected tyrosinase cDNA had promoted differentiation of the amelanotic cells into fully developed melanophores.
通过磷酸钙沉淀法，将编码黑斑蛙酪氨酸酶的cDNA导入培养的、酪氨酸酶阴性的 brevipoda 蛙无黑色素黑素细胞中。转染后的几天内，少数细胞出现了深色色素沉着。光学显微镜观察显示，这些转化细胞的形态与培养中的正常黑素细胞相当，其增殖活性低于无黑色素细胞。超微结构检查证实，无黑色素黑素细胞拥有相对较少的前黑素小体，而转化细胞含有大量处于色素沉积不同阶段的黑素小体。结果表明，黑斑蛙酪氨酸酶cDNA在brevipoda蛙无黑色素黑素细胞中表达，包括前黑素小体的成熟。还表明，转染的酪氨酸酶cDNA的表达促进了无黑色素细胞分化为完全发育的黑素细胞。
