Figure 1: Genome maps of Towne-varS, Towne-varL, and BAC-cloned viruses. Inverted repeats 𝑏 / 𝑏 and 𝑐 / 𝑐 (grey boxes) flank unique long (UL) and unique short (US) regions to delineate long and short genome segments. One or more copies of the a sequence (black bars) can be found at long segment termini and inverted at the long and short segment junction ( 𝑏 𝑎 𝑐 ), while one or no copies are found at short segment termini [9, 10] (for simplicity single copies are shown). Dashed lines indicate UL sequences in varL that are missing from varS; black boxes represent the BAC ori cassette (BAC). Nucleotide positions are indicated; genome features are approximately to scale.