Fig. 6
Scaled breeding steps for 1st, 2nd and 3rd generation of pigs to generate gene edited nucleus herd. A Advancing PRRSV resistance allele. Mosaic E0 pigs screened and identified to contain the desired CD163 allele are bred to wild-type gilts or boars to produce heterozygous CD163 (CD163m/WT) pigs. All E1 pigs are screened by Illumina and a subset then sequenced by hybridization capture to advance CD163m/WT pigs that do not contain detected off-target INDELs for breeding. E1 CD163m/WT pigs are then crossbred to fix the modified CD163 in a homozygous state (CD163m/m). These E2 CD163m/m pigs are then used for virus resistance testing, commercial performance equivalency, regulatory data submission and advanced for nucleus multiplication. CD163m/m pigs across four lines enter production pyramid upon approval. B Nucleus and conventional breeding. Approximately 10–20 high genetic merit CD163m/m boars across 2 maternal and 2 paternal lines are used to maintain a small nucleus population for multiplication and genetic improvement. Upon approval, these founders would be multiplied and distributed to producers for commercial production and sale using conventional breeding practices