Enzootic bovine leukemia is caused by the bovine leukemia virus (BLV). BLV is transmitted vertically or horizontally through the transfer of infected cells via direct contact, through milk, insect bites and contaminated iatrogenic procedures. However, we lacked direct evidence of intrauterine infection. The purpose of this study was to confirm intrauterine BLV infection in two pregnant dams wit...

Sixty-nine sheep were infected with bovine leukemia virus from bovine lymphosarcoma materials. Twenty-four developed lymphosarcoma and died from 13 to 66 (average, 29) months later. Circulating lymphocytes were increased to leukemia levels (70,000 to 403,000/cu mm blood) in only eight sheep within 2 to 3 months of death. Various lymph nodes and visceral organs including heart, abomasum, uterus,...

Here, we used a sheep bioassay to determine the effect of freezing colostrum to prevent the transmission of bovine leukemia virus (BLV) among neonatal calves. Leukocytes were isolated from the colostrum of a BLV-infected Holstein cow and were then either left untreated (control) or freeze-thawed. A sheep inoculated intraperitoneally with the untreated leukocytes was infected with BLV at 3 weeks...

Monoclonal antibodies directed against the feline leukemia virus (FeLV) envelope proteins, gp70 and p15E, were identified by radioimmunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Six of these monoclonal antibodies were specific for the gp70; two for the p15E. Enzyme-linked immunosorbent assay binding assays against FeLV subtypes A, B, and C showed that most of ...

Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leukosis. This study was conducted to clarify the molecular characteristics of BLVs obtained from a specific region in Korea. Proviral BLVs were detected in anti-BLV antibody-positive blood samples by PCR. Env and gag fragments were sequenced and compared to previously published reference sequences. Analysis of the env gene s...