Feline leukemia virus, strain KT, is a retrovirus that causes a fatal erythroid aplasia. The fatal loss of erythrocytes is due to the interaction of this virus with the BFU-E stage of feline erythropoietic development. This virus is comparable to the human HTLV retrovirus. Through the development of a computer mathematical model, we demonstrate the disease process and show that infection of the BFU-E leads to a characteristic fatal erythroid aplasia in cats.

Fetal feline lymphohematopoietic stem cells, before a certain point in gestation, lack genotypically unique class I major histocompatibility cell-surface antigens (FLA). The elucidation of a gestational time point when FLA appear on the surface of cells within the fetal liver will provide knowledge of when hematopoietic stem cells may be at maximal utility for gene therapy of feline hematopoietic disease, specifically FIV. Here we show that this time point occurs around day 40 in fetal feline gestation.