A novel C57BL/6 transgenic murine model of HbE has been developed, and the heterotetrameric ((m)alpha2(h)beta(E)2) hemoglobin shows significant complementation of mild thalassemia phenotype in double heterozygous (beta(m+)beta(m-), beta(hE)) and homozygous knockout (beta(m-)beta(m-), beta(hE)) mice with 100% heterotetrameric hemoglobin. Lethal homozygous beta-thalassemic mice rescued by HbE transgenes mimic beta-thalassemia/HbE phenotype in human. Although anemia was not pronounced, other hematologic parameters were abnormally similar to beta-knockout mice. Flow cytometric study revealed a highly oxidative status in the red cells, but there were no marked changes in PS red cells and RBC vesicles. RBC life span and half-time of rescued red cells were shortened, indicating a rapid RBC destruction.