Table 3.

Intercrosses of G1 progeny

Chimaera	Progeny crosses	Days mated	G1×G1 pups	G1×B6 pups/litter
v6.4-C1	C1B×C1A	50	0	6; 7
	C1D×C1C	50	0	0; 5.7
	C1F×C1E	11	0	10; 8.3
		10	2*
v6.4-C2	C2A×C2B	11	0	7.3; 6.5
		14	0
	C2C×C2B	20	3	8; 6.5
v6.4-C3	C3A×C3B	48	0	6.5; 3
v6.4-C7	C7B×C7A	27	2*	6; 6
			2
	C7D×C7C	84	2	3; −
	C7F×C7E	84	3	8.5; 2.5
	C7I×C7H	57	0	0; 7
	C7J ×C7K	57	3*	0; 4.2
CT129-C	TC2I×TC2F	68	6	7; 8
	TC2J×TC2G	68	5	−; 7
			8
	TC2K×TC2H	68	1	−; 7
			11

The animals listed in ‘Progeny crosses’ are G1 siblings of the corresponding chimaera, indicated as dam×sire. The length of time these crosses were performed is listed under ‘Days mated’. In some cases, the animals were mated twice, as indicated by separate line entries. The number of pups from these intercrosses is listed under ‘G1×G1 pups’. The values in ‘G1×B6 pups/litter’ are the average litter sizes of each G1 parent (dam; sire) when mated with C57BL/6J (a dash indicates that the animal was never outcrossed). The average of these averages is 5.3.

^*Pups died before weaning.