Sequence analysis for the complete proviral genome of avian leukosis virus subgroup J associated with haemangiomas, leiomyosarcomas and myelomas in layer flocks.
Avian leukosis virus subgroup J (ALV-J) can cause a variety of neoplasms, including mainly myeloid leukosis (myelocytomatosis) and nephromas. Other tumours, such as histiocytic sarcoma (HS), haemangiosarcoma and mesothelioma, may also develop. In a previous article we described a case in which myeloid leukosis, haemangiomas and leiomyosarcomas appeared simultaneously in a commercial layer flock with infection by ALV-J. The present research was completed to understand the molecular characteristics of the ALV-J strain that induced clinical myeloid leukosis, haemangiomas and leiomyosarcomas. Two strains of ALV-J (SDAU1001 and SDAU1002) were isolated and identified, and their full-length sequences were analysed. The complete genome nucleotide sequences of these two isolates were different in length, 7652 nt and 7636 nt, respectively. They shared 98.9% identity with each other, and 93.4% to 97.8% nucleotide identity to the reference ALV-J isolates. A 19-nucleotide repeat sequence was identified in the primer binding site (PBS) leader region of isolate SDAU1001. A base substitution mutation (base 15 C-T) in this insertion was identified. However, the identical insertion at the same site was not found in SDAU1002. The gag and pol genes of the two viruses were more conserved than the env gene. One key deletion in the E element was a common feature of SDAU1001 and SDAU1002. SDAU1001 and SDAU1002, possibly recombinants of ALV-J and another avian retrovirus, may share the same ancestor. Co-infection by SDAU1001 and SDAU1002 isolates is a possible explanation why myeloid leukosis, haemangiomas, and leiomyosarcomas appeared simultaneously in the same commercial layer flock.
Shandong Agricultural University College of Animal Science and Veterinary Medicine Taian 271018 P. R. China Chinese Academy of Agricultural Sciences Division of Avian Infectious Diseases, National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute Harbin, Heilongjiang P. R. China Liaoning Medical University College of Animal Husbandry and Veterinary Science Jinzhou City, Liaoning P. R. China.
Yue
Y
Qu
Honglei
H
Sun
Meiyu
M
Sun
Delong
D
Li
Liting
L
Qin
Yulong
Y
Gao
Xiaomei
X
Wang
Sidang
S
Liu
D000818:Animals; D001353:Avian Leukosis; D001354:Avian Leukosis Virus / Q000302:isolation & purification; D001483:Base Sequence; D002645:Chickens; D006391:Hemangioma / Q000662:veterinary; D007890:Leiomyosarcoma; D008969:Molecular Sequence Data; D011201:Poultry Diseases / Q000821:virology; D011533:Proviruses; D017421:Sequence Analysis