transfer of an 886-base-pair ( bp ) fragment of fsc , encompassing the codons for 73 amino acids at the 3 ' end of pol ( the integrase/endonuclease gene ) and the codons for 241 amino acids of the n-terminal portion of env [ the extracellular glycoprotein ( gp70 ) gene ] , into the f6a genome was sufficient to confer onto chimeric viruses the ability to induce fatal aplastic anemia in spf cats .
C0063690
integrase
C0042776
viruses