RADIATION HYPERSENSITIVITY OF LEC STRAIN RATS CONTROLLED BY A SINGLE AUTOSOMAL RECESSIVE GENE

LEC strain rats (LEC rats), which are known to develop hereditarily sp ontaneous fulminant hepatitis 4-5 months after birth, were highly sens itive to whole-body X-irradiation when compared to WKAH strain rats. T he radiosensitivity of F1 hybrids of LEC and WKAH rats was similar to that of WKAH rats and significantly lower than that of LEC rats. Segre gation data of backcross hybrids (F1 x LEC and LEC x F1) suggested tha t the hypersensitivity of LEC rats to whole-body irradiation is contro lled by a single autosomal recessive gene. The radiosensitivity of fib roblasts from LEC rats was higher than that of fibroblasts from WKAH r ats. The repair process of DNA double-strand breaks in LEC cells was s lower than that in WKAH cells. LEC rats could provide a useful animal model to assist in understanding the mechanism of radiation-induced DN A damage and repair.