1. Precision Genome Engineering in Livestock
Directed Genetic Modification Technologies: An Opportunity for Science-Based Regulatory Reform A Roundtable Workshop January 14, 2015

2. Precision Genetic Editing is a “Game Changer”
High gain, low risk Engineering
Genetic Engineering pre-2010
DNA sequences inserted randomly
Genome Editing post-2010
Precision DNA changes
Rate of HDR <10-7
Rate of HDR 0.4
4x106 X
Precision genetics => 1bp change in 3 x 109 bp!
Error rates (June 2014) are below minimal detection (10-4)

3. Better Nutrition & Improved Animal Welfare with Changing Environments
Applications of Gene-Edited Animals
Global
Improved Breeds for
local environments
Better Nutrition & Improved Animal Welfare with
Greater Diversity for
Changing Environments
Animal Models for
Biomedical Testing
Patient-Specific
Tissues & Cells
Personal

4. Livestock Gene Conversion with TALENs

5. TALEN-mediated SNP changes about 10% efficient (pigs)
TALEN-mediated HDR for gene editing 45% efficient, 32% biallelic (pigs)
TALEN-mediated SNP changes about 10% efficient (pigs)
Cas9/CRISPR-mediated SNP gene-editing average <10% efficient (pigs)
Tan et al (2013) PNAS

6. Gene-editing Technology
Relative Risks
Nature Biotech. (2013) 31:
Gene-editing Technology
regulation uncertain
Regulated
Unregulated
Low --- Likelihood of Unintended Change  High 6

7. Programmable endonucleases change the paradigm
Used to introduce targeted
mutations - Not GE
Used to target gene insertion - GE
Before regulating targeted mutagenesis consider this:
Base pair difference between any two humans ranges from
6 X 106 to 24 X 106
(Jorde et al., (2004). Nature Genetics 36 (11s): S28–33; Tishkoff et al., (2004). Nature Genetics 36 (11s): S21–7)
Will not be traceable, i.e. not different from natural mutation
From Jim Murray, UC-Davis

8. Transgenic Livestock Development
Lysostaphin, Lysozyme, Lactoferrin
Jim Murray & Elizabeth Maga, UC – Davis
Jim Murray & Elizabeth Maga, UC-Davis
Mark Westhusin & Chuck Long, TAMU
Matt Wheeler, Illinois
Kevin Wells, University of Missouri
Scott Fahrenkrug & Dan Carlson, Recombinetics
Chris Rogers, Exemplar
Avian Influenza Resistance
Helen Sang, Roslin
Aquadvantage Salmon, Aquabounty

9. Gene Edited Livestock WT Pitx3 Knockout No Human Stem Cells
RELA African Swine Fever Virus Resistance
Warthog to S. scrofus using TALEN in embryos (Roslin Institute & Recombinetics)
Recombinetics:
PCSK9 Gain-of-Function mutation using transgenic KO
LDLR mutation introduced using TALEN in cell cultures
Myostatin allele from Belgian Blue to Nelore (B. Taurus to B. Indicus); direct embryo modification using TALEN
(TAMU & Recombinetics)
Recombinetics WT
Pitx3 Knockout
No Human Stem Cells
+ Human Stem Cells

10. FDA Approved Transgenic Livestock
Glofish ® 2003
Atryn® Recombinant Antithrombin, 2009

11. Regulation of GE Animals
United States: Outcome based (in theory); (in truth) process based
By FDA as a “New Animal Drug”
Guidance-based only, i.e. no statutes
Canada: Novel Foods
Argentina, Australia, New Zealand: Process-based
Europe: fiat
Brazil: ???