Analysis of structural diversity in small regions of the <i>env</i> genes.

<p>Characteristic indels in different versions of the <i>env</i> gene are indicated by shaded boxes and labeled with lowercase letters, shown relative to the FeLV-A 61E sequence. (A) Three insertions identified in the Genotype I group: ‘a’ – insertion of AGT or AAT; ‘b’ – insertion of AATACAAGCAGT; ‘c’ – insertion of CCCCAC. (B) Three additional indels identified in the Genotype I group: ‘d’ – insertion of ACTACT; ‘e’ – insertion of CAGGGC; ‘f’ – deletion of three nucleotides at position 535–537 of the FeLV 61E sequence. Boxes with darker shading at ‘d’ indicate atypical deletions. (C) A single insertion identified in the Genotype II group: ‘g’ – insertion of CTT. (D) – (F) show these indels (‘a’ to ‘g’) plotted on various representations of the best phylogenetic tree shown in Fig. 3.