Radiation (Low Dose) -induced Apoptosis and It's Susceptibility Genes

1)控制辐射诱导小鼠胸腺细胞凋亡的显性和隐性基因：我们建立了一种灵敏的方法，通过在胸腺、脾、肠等器官的冰冻切片上用红素B染色死亡或死亡的细胞来检测凋亡。对辐射诱导的细胞凋亡敏感品系N4与抗性品系C3H/HeJ进行遗传杂交，发现1个显性基因表现为孟德尔遗传。连锁分析和微卫星标记检测表明，该基因与第4号染色体连锁。利用敏感品系C57BL/6J和抗性品系C3H/HeJ的重组近交系(BHX)发现了2个控制易感性的隐性基因。照射后24小时死亡细胞被清除，看起来像是单个细胞死亡。低温和环磷酰胺(蛋白质合成抑制剂)可抑制培养胸腺中淋巴细胞的凋亡。3)与淋巴细胞白血病的关系：对辐射诱导的凋亡高度敏感的小鼠品系也对辐射诱导的白血病易感，但RI株的分析表明与这些疾病相关的基因是不同的。

1) Dominant and recessive genes controling susceptibility to radiation induced apoptosis in the mouse thymus : We established sensitive method to detect apoptosis by staining dead or dying cells with erythrosines B in the frozen section of the organs (thymus, spleen, intestine, etc.). Single dominant gene showing Menderian inheritance was found by the genetic cross of radiation-induced apoptossis sensitive strain N4 and resistant C3H/HeJ.The examinations using linkage stocks and microsatellite markers revealed that this gene was linked to the chromosome 4. Another 2 recessive genes controling susceptibility were found by the use of recombinant inbred strain (BHX) of senstive strain C57BL/6J and resistant C3H/HeJ.2) Massive suicide deaths of thymic Iymphocytes : By the specific stainig method of the frozen sections, we found that thymic cells died massively but not singly at early stages (2-8 hours) after irradiattion. Dead cells were eliminated after then and it looks like single cell death 24 hours after irradation. Apoptosis of Iymphocytes in the cultured thymus was inhibited by low temparature and cyclophosphamide (inhibitor of protein synthesis) .3) Realation to Lymphocytic leukemia : Mouse strains showing high susceptibility to radiation-induced apoptosis are also susceptible to radiation-induced leukmia, but the analysis by RI strain showed that genes concerned to these disorders are different.