Differences in pathogenicity among strains of the same or different avian leukosis virus subgroups.

An efficient induction of wasting disease in chickens by avian leukosis virus (ALV), particularly ALV subgroup C, requires >102 infectious units virus inoculated in mid embryogenesis. The most conspicuous symptoms of the disease were induced by ALV subgroup C; however, significant differences in the occurrence of wasting disease were found among individual members of this subgroup. Almost comparable pathogenicity was exhibited by ALV subgroup D, whereas viruses of subgroups B and A proved to be moderately and almost non-pathogenic, respectively.

Opposite effects of modifiers of the ApcMin mutation in intestine and mammary gland.

Patterns of tumor susceptibility in different organs are widely divergent in mouse strains: one strain may be highly susceptible to tumors in one organ but resistant in another organ, whereas another strain may exhibit the opposite pattern (P. Demant, Semin. Cancer Biol.