Transgenic Animals - Technology and Applications
GOETZ LAIBLE, AGRESEARCHMWC - BIOLOGY TEACHERSPROFESSIONAL DEVELOPMENT DAYS6/7TH APRIL 2017
– Crown Research Institute in support of NZ’s pastoral industries
– Four major research centres • Ruakura• Grasslands• Lincoln• Invermay
• Total Staff 786 (full-time equivalent)
• Scientific/Technical Staff 405 FTE
• Science Groups• Animal Science (cattle, goats, sheep, deer)
• Food & Bio-based Products• Forage Science• Farm Systems & Environment• Knowledge & Analytics
AGRESEARCH – IN A NUTSHELL
Biomedical Biopharming Medical/functional foods Xenotransplantation Animal models of human diseases
Agricultural Improved quantity and quality of
animal production Improved animal health Sustainable agriculture
GM OF LIVESTOCK - A PLATFORM TECHNOLOGY FOR A VARIETY OF APPLICATIONS
Pronuclear Microinjection (1985)
TECHNOLOGICAL ADVANCES IN LIVESTOCK TRANSGENESIS
CLONING BY NUCLEAR TRANSFER
Wells et al., Biology of Reproduction, 1999Dolly the sheep, 1996
Pronuclear Microinjection
Somatic cell nuclear transfer (SCNT) with transfected cells (1997)
3. 2.
TECHNOLOGICAL ADVANCES IN LIVESTOCK TRANSGENESIS
Transfection of bovine cells
TransgenePromoter
GENERATION OF CLONED TRANSGENIC CATTLE
2.
Transfection of bovine cells
Oocyte enucleation
GENERATION OF CLONED TRANSGENIC CATTLE
3. 2.
Transfection of bovine cells
Oocyte enucleation
Fusion of donor cell and cytoplast
GENERATION OF CLONED TRANSGENIC CATTLE
3. 2.
Transfection of bovine cells
Oocyte enucleation
Fusion of donor cell and cytoplast
Activation of reconstructed
embryo
GENERATION OF CLONED TRANSGENIC CATTLE
3. 2.
Transfection of bovine cells
Oocyte enucleation
Fusion of donor cell and cytoplast
Embryo culture to blastocyst
Activation of reconstructed
embryo
GENERATION OF CLONED TRANSGENIC CATTLE
3. 2.
Transfection of bovine cells
Oocyte enucleation
Fusion of donor cell and cytoplast
Embryo culture to blastocyst
Activation of reconstructed
embryo
Embryo transfer
GENERATION OF CLONED TRANSGENIC CATTLE
Gene of InterestPromoter1) DNA construct
Secretion into milkActivated in the lactating mammary gland
4) Extraction of the pharmaceutical protein from milk and use as a drug for disease treatments
2) Stable integration of the DNA construct into the genome
3) Mammary gland produces large amounts of proteins that are readily accessible in milk
THE CONCEPT OF BIOPHARMING
Hereditary angioedema
BIOPHARMING – ALREADY A REALITY
rEVO Biologics2006 EMA/2009 FDA
Pharming NV2010 EMA/2014 FDA
ATryn® (antithrombin alpha)
Congenital antithrombindeficiency
RuconestTM (C1 esterase inhibitor)
KanumaTM (sebelipase alfa)
Alexion Pharmaceuticals2015 EMA/2015 FDA
Lysosomal acid lipase deficiency
Biosimilar antibody Cetuximab produced in the milk of goats
Erbitux approved for the treatment of metastatic colorectal cancer and head and neck cancer
LC
HC Puro
SCNT
GOATS PRODUCING AN ANTI-CANCER mAB
TG FOOD ANIMALS – A DIFFERENT STORY
Salmon with enhanced growth characteristics due to a growth hormone transgene
1989 – TG salmon generated
1995 – application for approval filed2009 – last supporting dataset submitted2010 – classified as safe to eat and safe for the environment and
recommended for approval
1993 – discussions with FDA initiated
– process stalled again and no final decision announced for
22 years in the regulatory maze
another 5 years
AquAdvantage salmon –approved for human consumption in November 2015
1ST TG FOOD ANIMALS APPROVED
Blocked by pending federal bill in March 2016 requesting new impact study on wild salmon stocks
ELIMINATING AN ALLERGY CAUSING PROTEIN PROTEIN
Daisy (with micro RNA)
BLG
Visualised milk proteins
Jabed et al., PNAS, 2012
Pronuclear Microinjection (1985)
Somatic cell nuclear transfer (SCNT) with transfected cells (1997)
ZFNs Zinc finger nucleases
TALENs Transcription activator-like effector nucleases
CRISPRs Clustered regularly interspaced short palindromic repeat (CRISPR) – Cas9 nucleases (2012)
GENETIC ENGINEERING ADVANCES IN LIVESTOCK
Genome Editing
*
* As of March 2017
Scientific publications mentioning CRISPR, 2007-2017
THE CRISPR REVOLUTION
ZFNs, TALENs and CRISPRs
Introduction of specific double strand breaks
TTTTTTTTTTTT
TTTTTTTTTTTT
small deletions small insertions
Non homologous end joining (NHEJ)
GENOME EDITING WITHOUT FOOTPRINT
CRISPR-mediated disruption (1506 bp deletion) of the CD163 gene
Whitworth et al., Nature Biotechnology, 2016
Whitworth et al., Biology of Reproduction, 2014
PRRSV-RESISTANT PIGS
WT
KO
(Procine Reproduction and Respiratory Syndrome Virus)
Rapid generation of elite genotypes by directly introducing beneficial natural mutations
Homologous recombination
T
TTTTT T
TTTTT
T
TTTTT T
TTTTT
T
TTTTT T
TTTTT
MOLECULAR BREEDING
HornlessHeat tolerant
ACCESSING THE BEST VARIANTS OF ALL GENES
Tan et al., PNAS, 2013
HORNLESS DAIRY CATTLE
Carlson et al., Nature Biotechnology 2015
Horned dairy cattle
Polled beef cattle
Polled dairy cattle
• A one amino acid change in ruminants prevents signal peptide cleavage of CD18 and generates binding site for bacterial leukotoxin
• Cell-mediated editing (correction) with ZFNs
Shanthalingam et al., PNAS 2016
SHIPPING FEVER-RESISTANT CATTLE
Introducing a ‘novel’ mutation
TUBERCULOSIS-RESISTANT CATTLE
Wu et al., PNAS 2015
Enhancing transgenesis with genome editing tools
ANIMALS FOR TRANSPLANT ORGANS
LARGE ANIMAL MODELS FOR HUMAN DISEASES
Mice have been the model of choice but differences in size and physiology to humans can be major shortcomings
Size, life span, physiology of large animals are more similar to humans
Enables study of chronic degenerative disease processes and testing of new therapeutic strategies and drugs
Cystic fibrosisCFTR KO and common human mutation ∆508Recapitulate devastating lung infections
LIVESTOCK MODELS OF HUMAN DISEASES
Huntington’s diseaseHTT transgene with 73 Q repeat
Rogers et al., Science 2008Pezzulo ey al., Nature 2012
Jacobsen et al., Hum Mol Genet 2010
Chris Slane, Farmers Weekly, 15 October 2012