MORPHOLOGIC AND CHROMOSOMAL STUDY OF A HUMAN RETINAL-PIGMENT EPITHELIAL-CELL LINE

A spontaneously established cell line of human retinal pigment epithel ium (RPE) was investigated morphologically and studied by chromosomal analysis. Even after the 100th passage, cultured cells maintained epit helioid morphology, and had numerous microvilli and membrane-bound sma ll dense bodies which looked like lysosomes. Abundant rough-surfaced e ndoplasmic reticulum and mitochondria were observed in the cytoplasm, suggesting that these cells were metabolically active. The absence of pigmentation was noted from the 6th passage. In chromosomal analysis, a small number of 2nd passage cells showed karyotypic changes. At the 12th passage, a single cell line (44, 6-monosomy and Y-missing) was es tablished. By the 100th passage, further karyotypic changes were noted (low tetraploid). The 6-monosomy might have played an important role in the establishment of this cell line. These results indicated that t his cell line underwent some changes in chromosomal count and pigmenta tion but retained many original morphological characteristics. After f urther evaluation of its characteristics, this cell line, K-1034, coul d be useful experimental material in the study of the function of the human RPE.