Transgenic avian line resistant to avian leukosis virus

Abstract

A transgenic avian line, which is resistant to infection by avian leukosis virus (ALV), subgroup A, has been produced. The line was discovered as a chance event occurring in a program of infecting embryonic chickens with a recombinant ALV virus, selecting individuals assayed to be positive for genomic insertion of proviral sequences, and backcrossing to the original line to obtain G1 progeny demonstrating stable inheritance of the inserts. Of at least three proviral inserts defective for ALV production, one was found to be capable of expressing in the cell membrane subgroup A envelope glycoprotein which specifically interferes with infection by subgroup A virus. This insert represents an artificially introduced dominant gene for ALV disease resistance. Through an appropriate breeding program, a line of chickens homozygous for this gene has been obtained.

We claim: 
     
       1. A chicken line, derived from a strain of chickens which is susceptible to avian leukosis virus infection, which chicken line has integrated in its genome a proviral sequence which expresses an envelope glycoprotein of a noninfectious subgroup A avian leukosis virus, and is thus genetically resistant to avian leukosis virus, subgroup A. 
     
     
       2. A chicken line as described in claim 1 wherein the genome comprises the provirus alv6. 
     
     
       3. A chicken line as described in claim 2 wherein the genome is homozygous for alv6. 
     
     
       4. A chicken, derived from a strain of chickens which is susceptible to avian leukosis virus infection, which chicken has integrated in its genome a proviral sequence which expresses an envelope glycoprotein of a noninfectious subgroup A avian leukosis virus, and is thus genetically resistant to avian leukosis virus, subgroup A. 
     
     
       5. A chicken as described in claim 4 wherein the genome comprises the provirus alv6. 
     
     
       6. A chicken as described in claim 5 wherein the genome is homozygous for alv6.