DISTRIBUTION OF ENDOGENOUS TYPE-B AND TYPE-D SHEEP RETROVIRUS SEQUENCES IN UNGULATES AND OTHER MAMMALS

The jaagsiekte sheep retrovirus (JSRV), which appears to be a type B/D retrovirus chimera, has been incriminated as the cause of ovine pulmo nary carcinoma, Recent studies suggest that the sequences related to t his virus are found in the genomes of normal sheep and goats, To learn whether there are breeds of sheep that lack the endogenous viral sequ ences and to study their distribution among other groups of mammals, w e surveyed several domestic sheep and goat breeds, other ungulates, an d various mammal groups for sequences related to JSRV, Probes prepared from the envelope (SU) region of JSRV and the capsid (CA) region of a Peruvian type D virus related to JSRV were used in Southern blot hybr idization with genomic DNA followed by low- and high-stringency washes . Fifteen to 20 CA and SU bands were found in all members of the 13 br eeds of domestic sheep and 6 breeds of goats tested. There were simila r findings in 6 wild Ovis and Capra genera, Within 22 other genera of Bovidae including domestic cattle, and 7 other families of Artiodactyl a including Cervidae, there were usually a few CA or SU bands at low s tringency and rare bands at high stringency, Among 16 phylogenetically distant genera, there were generally fewer bands hybridizing with eit her probe, These results reveal wide-spread phylogenetic distribution of endogenous type B and type D retroviral sequences related to JSRV a mong mammals and argue for further investigation of their potential ro le in disease.