FIG 1.

Receptor-binding domains (RBDs), proline-rich regions (PRRs), C domains, and TM regions of the Env protein are shown for FeLV-A clone 33 (17), FeLV-A Glasgow-1 (9), FeLV-C Sarma (19), FeLV FY981 (21), FeLV TG35-2 (16), TG35-4 (accession number LC029807), and TG35-5 (accession number LC029808). The variable regions, VRA and VRB, are also shown. Dots indicate identical residues, and dashes indicate spaces that were introduced for the amino acid alignment. Boxes indicate the positions of the PCR primers (16). The Env sequences were aligned with the Genetyx program (Genetyx Corporation, Tokyo, Japan).