Supplementary Data Comparison of in vitro embryo and piglet editing frequency For RELA TALEN mRNA injected zygotes we transferred 393 embryos into 11 recipient sows, resulting in 6 pregnancies and 5 farrowings with litter sizes ranging from 3 to 17. One female aborted within the last two weeks of pregnancy. Of the 46 piglets born, 5 were stillborn while of the live born 13 were savaged, sat on by the sow or culled on veterinary advice. Post mortem investigation failed to detect any common pathology associated with the dead piglets. In comparison to previous studies describing the combination of genome editing tools and SCNT, zygote injection represents an efficient technology. In our work described here 32 donor/recipient animals were used to produce 9 edited piglets. In contrast the generation of genome edited pigs by SCNT used, for example, approximately 75 donor/recipients to produce 2 edited animals12 while approximately 84 donor/recipient animals were used to produce 11 edited piglets in a report of biallelic genome editing10; assuming 20 oocytes per donor animal. Supplementary Fig 1. Example TALEN edited pig (#26) carrying single base deletion with sequence read of single base pair edited allele and wild-type RELA allele. TALEN binding site GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATGCTGATGGAGTACCCTGAGGCTATAACTC WT Zygote 1 GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATGCTGATGGAGTACCCTGAGGCTATAACTC WT GGTGTATCCATGCCCCCCCACACAGCTGAGCCC~~~~TGATGGAGTACCCTGAGGCTATAACTC 4 GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATGCTAGTGGAGTACCCTGAGGCTATAACTC 2+2 Zygote 2 GGTGTATCCATGCCCCCCCACACAGCTGAG~CCATGCTGATGGAGTACCCTGAGGCTATAACTC 1 Zygote 3 GGTGTATCCATGCCCCCCCACACAGCTGAGCCCA~~~~~ATGGAGTACCCTGAGGCTATAACTC 5 Zygote 4 GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATGCTGATGGAGTACCCTGAGGCTATAACTC WT GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATTGCTGATGGAGTACCCTGAGGCTATAACT +1 Zygote 5 GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATGCTGATGGAGTACCCTGAGGCTATAACTC WT GGTGTATCCATGCCCCCCCACACAGCTGAGCCC~TGCTGATGGAGTACCCTGAGGCTATAACTC 1 Zygote 6 GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATGCTGATGGAGTACCCTGAGGCTATAACTC WT GGTGTATCCATGCCCCCCCACACAGCTGAGCCC~~~~TGATGGAGTACCCTGAGGCTATAACTC 4 Zygote 7 GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATGCTGATGGAGTACCCTGAGGCTATAACTC WT GGTGTATCCATGCCCCCCCACACAGCTGAGCCCA~GCTGATGGAGTACCCTGAGGCTATAACTC 1 Zygote 8 GGTGTATCCATGCCCCCCCACACAGCTGAGCC35TGCTGATGGAGTACCCTGAGGCTATAACTC 2+35 ACAAGTCGAGGGTCTCAGAGTCACTGAGTACTGAG Zygote 9 GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATGCTGATGGAGTACCCTGAGGCTATAACTC WT GGTGTACCCATGCCCCCCCACACAGCTGAGCCCA~~~~~ATGGAGTACCCTGAGGCTATAACTC 5 Zygote 10 GGTGTATCCATGCCCCCCCACACAGCTGAGCCCT~~~~GATGGAGTACCCTGAGGCTATAACTC 4 Zygote 11 GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATGCTGATGGAGTACCCTGAGGCTATAACTC WT GGTGTATCCATGCCCCCCCACACAGCTGAGCC~ATGCTGATGGAGTACCCTGAGGCTATAACTC 1 GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATGCTGATGG~~~~CCCTGAGGCTATAACTC 4 Zygote 12 GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATGCTGATGGAGTACCCTGAGGCTATAACTC WT GGTGTATCCATGCCCCCCCACACAGCTGAGCC~ATGCTGATGGAGTACCCTGAGGCTATAACTC 1 Zygote 13 GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATGCTGATGGAGTACCCTGAGGCTATAACTC WT GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATG~TGATGGAGTACCCTGAGGCTATAACTC 1 GGTGTATCCATGCCCCCCCACACAGCTGAGCCCAT~~TGATGGAGTACCCTGAGGCTATAACTC 2 Zygote 14 GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATGCTGATGGAGTACCCTGAGGCTATAACTC WT GGTGTATCCATGCCCCCCCACACAGCTGAGCC~ATGCTGATGGAGTACCCTGAGGCTATAACTC 1 Zygote 15 GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATGCTGATGGAGTACCCTGAGGCTATAACTC WT GGTGTATCCATGCCCCCCCACACAGCTGAGCCC~~~~TGATGGAGTACCCTGAGGCTATAACTC 4 Zygote 16 GGTGTATCCATGCCCCCCCACACAGCTGAGC~~ACACA~~~GGAGTACCCTGAGGCTATAACTC 10+5 Zygote 17 GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATGCTGATGGAGTACCCTGAGGCTATAACTC WT GGTGTATCCATGCCCCCCCACACAGCT~~~~~~~~~~~GATGGAGTACCCTGAGGCTATAACTC 11 Zygote 18 GGTGTATCCATGCCCCCCCACACAGCT~~~~~~~~~~~~~~~GAGTACCCTGAGGCTATAACTC 15 Zygote 19 GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATGCTGATGGAGTACCCTGAGGCTATAACTC WT GGTGTATCCATGCCCCCCCACACAGCTGAGCCCA~~~TGATGGAGTACCCTGAGGCTATAACTC 3 Zygote 20 GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATGCTGATGGAGTACCCTGAGGCTATAACTC WT GGTGTATCCATGCCCCCCCACACAGCTGA~~~~~~GCTGATGGAGTACCCTGAGGCTATAACTC 6 Zygote 21 GGTGTATCCATGCCCCCCCACACAGCTGAGCCCACAGCTGGTACTCAGATGGAGTACCCTGAGGCTATAACT +9 GGTGTATCCATGCCCCCCCACACAGCT~~~~~~~~~~~GATGGAGTACCCTGAGGCTATAACTC 11 Supplementary Fig 2. Sequence of indels identified in zygotes. Zygotes 1-16 were injected with 20ng/ul TALEN mRNA and screened for GFP. Zygotes 17 & 18 were injected with 20ng/ul TALEN mRNA and were screened for development. Zygotes 19 – 21 were injected with 2ng/ul TALEN mRNA. TALEN binding site GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATGCTGATGGAGTACCCTGAGGCTATAACTC WT Piglet 8770-I GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATGCTGATGGAGTACCCTGAGGCTATAACTC WT GGTGTATCCATGCCCCCCCACACAGCTGAGCCCA~GCTGATGGAGTACCCTGAGGCTATAACTC 1 Piglet 8770-J GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATGCTGATGGAGTACCCTGAGGCTATAACTC WT GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATTGCTGATGGAGTACCCTGAGGCTATAACT +1 Piglet 8770-26 GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATGCTGATGGAGTACCCTGAGGCTATAACTC WT GGTGTATCCATGCCCCCCCACACAGCTGAGCCCA~GCTGATGGAGTACCCTGAGGCTATAACTC 1 Piglet 8130-so GGTGTATCCATGCCCCCCCACACAGCTGA~~~~~~GCTGATGGAGTACCCTGAGGCTATAACTC 6 Piglet 8130-16 GGTGTATCCATGCCCCCCCACACAGCTGAGCCCATGCTGATGGAGTACCCTGAGGCTATAACTC WT GGTGTATCCATGCCCCCCCACACAGCTGAGCCCTCCATCAGCTGATGGAGTACCCTGAGGCTAT +5 GGTGTATCCATGCCCCCCCACACAGCTGAG~~~~~~~~~~~~~~~~~CCCTGAGGCTATAACTC 17 Inserted sequence is duplication/inversion of orange highlighted Piglet 8784-30 GGTGTATCCATGCCCCCCCACACAGCTGAGC~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 111 GGTGTATCCATGCCCCCCCACACAGCTGAGCC~~~~CTGATGGAGTACCCTGAGGCTATAACTC 4 Piglet 8784-33 GGTGTATCCATGCCCCCCCACACAGCTGAGC~~~~~CTGATGGAGTACCCTGAGGCTATAACTC 5 GGTGTATCCATGCCCCCCCACACAGCTGAG~~~~~~CTGATGGAGTACCCTGAGGCTATAACTC 6 GGTGTATCCATGCCCCCCCACACAGCTGAGCC~~~~CTGATGGAGTACCCTGAGGCTATAACTC 4 Piglet 8784-34 GGTGTATCCATGCCCCCCCACACAGCTGAGCCCA~GCTGATGGAGTACCCTGAGGCTATAACTC 1 GGTGTATCCATGCCCCCCCACACAGCTGAGCCCTGAGTACCCTGAGGAGTACCCTGAGGCTATA 8+12 Inserted sequence is duplication of orange highlighted ZFN binding site TGCTGATGGAGTACCCTGAGGCTATAACTCGCTTGGTGACAGGGTCCCAGAGACCCCCTGACC WT Piglet 8142-C TGCTGATGGAGTACCCTGAGGCTATAACTC~~~~~~~~~TCTGGGA~~~~~~~~~CCCTGACC 25+7 Inserted sequence is inversion of orange highlighted in consensus Supplementary Fig 3. Sequence of indels identified in piglets.