||High Radiosensitivity of Bone Marrow Cells in GFP Transgenic Mice
Ninomiya, Yasuharu ,
Tanaka, Kaoru ,
Nenoi, Mitsuru ,
nenoi, MitsuruWang , Bing
Transgenic mice ubiquitously expressing green fluorescent protein (GFP) are frequently used in radiobiology for various purposes. But, equivalence of the GFP mice with their wild-type counterparts in regard of radiosensitivity has not been confirmed yet. In this study, we analyzed radiosensitivity of thymus, spleen and bone marrow, using GFP transgenic mice (GFP-BL/6N) and their wild-type counterparts (BL/6N). As a result, the forward and side scatter plot in flowcytometry analysis showed an elevated cell death in bone marrow of GFP-BL/6N compared to that in BL/6N after X-irradiation with 4 Gy. When radiosensitivity of each type of cells in bone marrow was analyzed by using a gate of cell sorter for myeloid and lymphoid, the number of myeloid cells of GFP-BL/6N was found to decrease more extensively than that of BL/6N 3 hr after X-irradiation with 4 Gy. TUNEL assay revealed an elevated apoptosis of myeloid cells of GFP-BL/6N compared to that of BL/6N 3 hr after X-irradiation with 4 Gy. In addition, expression of bax gene in bone marrow cells was found to be increased more extensively in GFP-BL/6N than in BL/6N after X-irradiation with 4 Gy. These results indicated bone marrow cells of GFP-BL/6N are radiosensitive to high dose of X-irradiation than that of BL/6N.