育種・遺伝2

[II-16-29] Comparison of BLV infectivity between bovine leukemia virus susceptible and resistant cattle

*白 ランラン^1,2、包 陸拾七 ²、佐藤 洋隆²、竹嶋 伸之輔^2,3、智一 福田¹、朝治 桜子⁴、安藤 麻子^4,5、猪子 英俊　⁴、間 陽子^2,6 (1. 岩手大学　理工学部、2. 理化学研究所　分子ウイルス特別研究ユニット、3. 十文字学園女子大学　食物栄養学科、4. ジェノダイブファーマ株式会社、5. 東海大学　医学部　基礎医学系 分子生命科学、6. 東京大学　生命科学研究科・農学部)

Bovine leukemia virus (BLV) infects cattle worldwide and induces severe economic losses. The major transmission route is via infected blood. Polymorphisms of bovine lymphocyte antigen (BoLA)-DRB3 alleles are related to susceptibility to BLV proviral load (PVL). However, whether differential BoLA-DRB3 alleles affect BLV infectivity is still unclear. Here, we evaluated BLV infectivity in susceptible and resistant cattle in a three-year follow-up investigation. The BoLA-DRB3 alleles, PVLs, and infectivity were analyzed. Among tested 179 cattle, the rates of susceptible and resistant alleles were 22 % and 16%, respectively. The mean PVL of resistant cattle was significantly lower than those of susceptible and neutral cattle. Susceptible cattle showed stronger BLV infectivity than both resistant and neutral cattle. BLV-infected resistant cattle were found to be at a low risk of BLV transmission owing to weak BLV infection and low PVL. Our results show that the BoLA-DRB3 allele directly or indirectly associates with BLV infectivity. The breed selection based on resistant BoLA-DRB3 allele is an effective strategy for reducing and controlling BLV infection.