Table 2. Breeding chimeric founder females.
| Clone | ♀ (% chimerism) | Pups | Germ-line transmission |
|---|---|---|---|
| Ms (clone S2) | 13 (20) | 19 | 0/19 |
| 26 (15) | 54 | 0/47 | |
| 33 (5) | 10 | 0/5 | |
| 37 (1) | 20 | 1/15 (♂) | |
| Ms (clone S3) | 2 (10) | 46 | 0/35 |
| 16 (20) | 29* | 0/27 | |
| 17 (5) | 9 | 0/9 | |
| Md (clone D6) | 1 (20) | 48 | 0/48 |
| 27 (20) | 33 | 0/33 | |
| Md (clone D7) | 1 (90) | 31 | 0/26 |
| 2 (10) | 32 | 0/29 | |
| 34 (80) | 34 | 1/33 (♂) | |
| 35 (80) | — | — | |
| 55 (90) | 31 | 3/23 (2♀/1♂)† | |
| 62 (95) | 57 | 0/38 | |
| 63 (85) | 59 | 1/46 (♂) | |
| 87 (85) | 17 | 0/14 | |
| 89 (80) | 8 | 0/7 |
Weaned chimeric founder females (heteroplasmic for either Ms or Md mitochondria) were bred with B6 males to generate homoplasmic offspring. Breeding of the Ms chimeric founder female S2 #37 (generated from the S2 clone) resulted in the germ-line transmission of Ms mtDNA in one male pup. This pup was homoplasmic for Ms mtDNA. Similarly, breeding of Md chimeric founder females D7 #34 and #55 (generated from the D7 clone) to B6 males resulted in the germ-line transmission of Md mtDNA to one male pup each that was homoplasmic for Md mtDNA. The three homoplasmic xenomitochondrial offspring had agouti fur pigmentation; all other offspring from female lineages bred to control B6 males had black fur.
Chimera S3 #16 died at 5 weeks of age. Ovaries were harvested and transferred to nude female recipients to attempt lineage rescue
Pups from chimera D7 #55 died or were killed within 24 h after birth