Avian leukosis virus Rous sarcoma virus

GG G C

CCA

C GC GU AC GG C

A G

CU G C

AGA

U GC GU AC GG C

A C

..CCCGGG..

..GGGCCC....GACGUC....CUGCAG..

VL30 ..UGUCUUGUC..

Human foamy virus ..UCCCUAGGGA..

Moloney murine leukaemia virus

GA C

GG CG CG UC GU AU AC GG U

A A

GA C

GA UG UG CG CU AC GC GC G

A A

Maedi visna virus

Human T cell lymphotropic virus type 1

CA

GC GU AC GU AC G AA

a

b

c

d

e