1National Research Institute of Aquaculture, Fisheries Research Agency, Minami-Ise, Mie 516-0193, 2Pearl Research Laboratory, K. MIKIMOTO & CO., LTD., Shima, Mie 517-0403, 3Graduate School of Bioresources, Mie University, Tsu, Mie 514-8507, 4School of Marine Biosciences, Kitasato University, Sagamihara, Kanagawa 252-0373, Japan
A method of forming pearls by transplanting outer epithelial cells (OEC) isolated from the mantle of pearl oyster Pinctada fucata was investigated. Two methods, 1) injection of OEC around the pearl nucleus inserted beforehand and 2) insertion of the pearl nucleus carrying a small pit inoculated with OEC, were compared in terms of performance. As a result, method 2 had a higher pearl formation rate than method 1. With method 2, about 70% of the inserted nuclei formed the nacreous layer when OEC were inoculated at 1×104 cells/nucleus. Next, OEC isolated from two types of pearl oyster that significantly differed in color (yellowness) of the shell nacre were mixed at four different ratios, and the prepared OEC mixtures were transplanted by method 2 to investigate the effects of the blend on the yellowness of harvested pearls. The yellowness of harvested pearls differed significantly in accordance with the mixing ratio.