Preliminary Research On Primary Cell Culture Of Chinemys Reevesii And Its Resistance To Ionizing Radiation

Objective: To build up a primary culture system of Chinemys reevesii cells. To investigatethe damage of DNA in primary culture cells after ionizing radiation and the damage change withtime going on. To investigate the change of distribution in cell cycle and the apoptosis of theprimary culture cells after ionizing radiation. Method: After primary culture and subculture, thebrain cells (TBCs) and the liver cells (TLCs) of Chinemys reevesii were irradiated by 5Gy ofX-ray with straight line ion accelerator, then the damage and restoration of DNA in cells weredetected by single cell gel electrophoresis. The primary culture cells of young mandarin fishwere contrasted. The change of cell cycle was detected by flow cytometry after TBCs irradiatedby 5Gy of X-ray which were cultured for 5 days. The ultrastructure of TBCs was observed withtransmission electron microscope after TBCs was irradiated by 8 Gy of X-ray. Results: (1) TBCsand TLCs of primary culture growed well and growed steadily for 3 generation. The fourthgeneration of TBCs showed gathering growth and "spontenous transformation" occurred fromthe fifth generation of TBCs, and the "transformed" TBCs grows well till 12 subcultures. TLCspropagated hardly after the first passage and became declined at the third passage. (2) Thesignificant damages of DNA in TBCs and TLCs were detected after 4 hours irradiated by 5 GyX-ray. The damages were repaired after 24 hours for TBCs and 48 hours for TLCs and showedno significant differences compared with unirradiated group (P＞0.05). The cells of youngmandarin fish were damaged badly and died mostly at the third day after irradiation. (3) TBCswas induced apoptosis, and the character was karyopyknosis after irradiated by 8 Gy X-ray.There were some mitochondria swelling in cells, and the ridge of mitochondrion was blurry ordisappeared. The endoplasmic reticulum was swollen and vacuolization. (4) There was no distinct change in cell cycle after irradiated by 5 Gy X-ray. Conclusion: (1) The cell that can becultured primarily and can transfer in vitro was young TBCs. (2) The DNA in TBCs and TLCs ofprimary culture were damaged seriously at early time and the damages were repaired atadvanced stage after irradiation. (3) There was definite capacity for resisting X-ray irradiation inChinemys reevesii cells.