TABLE 1.

Analysis of DI RNAs of the R638Aorig virus

No. of DI RNA for PA or PB1	Length of DI RNA	5′ Junctiona	3′ Junctiona
PA
1	365 (304,b 247c)	144	2,012
2	522 (461,b 404c)	168 (169)	1,879 (1,880)
PB1
3	515	163	1,989
4	555	228	2,014
5	577	251	2,015
6	789	337 (338)	1,891 (1,890)
7	1,162	358	1,895

^aJunctions(5′ and 3′) are defined numerically with respect to the parent segment (mRNA sense). Alternative junctions, due to local homology, are given in brackets.

^bObserved lengths in primer extension (Fig. 3).

^cObserved lengths in RT-PCR assay (Fig. 4).