Paul VincelliExtension Professor andProvost’s Distinguished Service ProfessorUniversity of Kentucky

GMO Crops: Basic Concepts, Risks and Benefits

Part I. GMO Crops: Basic Concepts

Word processing: a metaphor for how genetic engineering works

Nature, the “Mother of all Frankenfoods”

Compare/contrast to other crop improvement techniques

Discussion: Future programming needs

Part II. GMO Crops: Risks and Benefits

Examples of present-day GMO crops, and impacts

Potential risks of GMO crops Potential benefits of GMO crops Discussion: Future programming

needs

Google searches for “GMO”

www.google.com/trends

2005 2007 2009 2011 2013

Relative number of searches

Scientific information is necessary but insufficient

http://prestonhull.bpweb.net/Fight.html

Some recommendations on communicating science

All crops are genetically modified

Image from http://evolution.berkeley.edu/evolibrary/news/070201_corn

All crops are genetically modified

http://vozpopuli.com/next/50980-asi-hemos-moldeado-geneticamente-el-tomate-en-los-ultimos-10-000-anos?utm_content=buffer66b36&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer

Crops without genetic modification

http://www.geneticliteracyproject.org/2014/06/19/how-your-food-would-look-if-not-genetically-modified-over-millennia/

Gene expression

DNA RNA Protein

Conventional breeding vs. transgenesis (GMO)

http://www.csiro.au/files/images/ph8g.jpg

Plant transformationAgrobacterium

Biolistics

http://www.genomenewsnetwork.org/articles/12_01/A_tumefaciens_genome.shtml https://physics.ucsd.edu/~groisman/Gene%20guns.html

Word processing

A metaphor for how genetic engineering works

Is genetic engineering “unnatural”?

“Ick” vs. “Cool!”

Some natural genetic processes

“Scrambling” of genetic material (within an organism)

Transfer of gene fragments (between organisms)

“Scrambling” of genetic material (within an organism)

Transposons (“jumping genes”)

https://www.broadinstitute.org/files/news/stories/full/transposons_720x720_v2.jpg

Some transposons are active in crops

New insertions in rice indicated by arrows

Naito et al, 2006. Dramatic amplification of a rice transposable element during recent domestication. PNAS 103, 17620

Transposon-produced defect in chlorophyll biosynthesis

Dooner and Weil, 2013. Transposons and gene creation. In Fedoroff, 2013. Plant Transposons and Genome Dynamics in Evolution. J. Wiley and Sons.

Transposons (“jumping genes”)

From Feschotte et al. 2002. Nature Review Genetics 3:329

Chimerical genes created by one of Nature’s “cut-and-paste” tools

Normal wp allele

wp alleles with captured fragments of exons and introns

Zabala and Vodkin, 2007. Novel exon combinations generated by alternative splicing of gene fragments mobilized by a CACTA transposon in Glycine max. BMC Plant Biology 7:38

Transposable elements in monocot crops

From Plant Transposable Elements, 2012

Transfer of gene fragments (between organisms)

Paradigm: Evolutionary branches do not share genetic material

http://www.dnabaser.com/articles/phylogenetic-tree/phylogenetic-tree-big.jpg

Proposed inter-kingdom transfer of GT28 domain

From: Song D, Cho WK, Park S-H, Jo Y, Kim K-H (2013) Evolution of and Horizontal Gene Transfer in the Endornavirus Genus. PLoS ONE 8(5): e64270. doi:10.1371/journal.pone.0064270

www.pnas.org/cgi/doi/10.1073/pnas.1319929111

Sun B-F, et al. (2013) Multiple Interkingdom Horizontal Gene Transfers in Pyrenophora and Closely Related Species andTheir Contributions to Phytopathogenic Lifestyles. PLoS ONE 8(3): e60029. doi:10.1371/journal.pone.0060029

5:2876 | DOI: 10.1038/ncomms3876

Genome Research, 2014, http://www.genome.org/cgi/doi/10.1101/gr.164400.113.

Walshet al, 2013, PNAS 110:1012-1016

http://www.pnas.org/content/early/2012/01/23/1114076109

Nature Reviews: Genetics, 2008, doi:10.1038/nrg2386

Metcalf et al, 2014. Antibacterial gene transfer across the tree of life. eLife 2014;3:e04266. DOI: 10.7554/eLife.04266

Horizontal gene transfer is “fairly common in nature.”

Bioessays , 868–875, 2013

Plant genomes are highly dynamic

Some natural genetic processes

“Scrambling” of genetic material (within an organism)

Transfer of gene fragments (between organisms)

Generating biodiversity

Basis for selection of adapted biotypes

Genetic engineering vs. other disruptive breeding techniques

Protoplast fusion overcomes hybridization barriers

Image from http://www.syntheticsomaticseeds.org/protoplast-fusion

Through protoplast fusion, “…we can create new species of plants…”

Forced crossing can be highly mutagenic

Wang et al, 2005. Extensive de Novo Genomic Variation in Rice Induced by Introgression From Wild Rice (Zizania latifolia Griseb.). Genetics 170: 1945–1956

Tissue culture: somaclonal variation & activation of jumping genes

See: Scnnell et al, 2015. A comparative analysis of insertional effects in genetically engineered plants: considerations for pre-market assessments. Transgenic Research 24:1-7, etc.

Mutation breeding: unknown genetic changes

De: Bjorn Sigurbjornsson, “Induced Mutations in Plants.” Copyright © 1970 by Scientific American, Inc. All rights reserved.

http://www.wasatchorganics.com/products-page/grapefruit/organic-henderson-grapefruit-duplicate/

Other methods of crop improvement

Schnell et al, 2015. A comparative analysis of insertional effects in genetically engineered plants: considerations for pre-market assessments. Transgenic Research DOI 10.1007/s11248-014-9843-7

New developments in genetic engineering

Extremely targeted genetic changes

Gene expression

DNA RNA Protein

Gene silencing (RNAi)

DNA ProteindsRNA

Potato with 50% less acrylamide, less bruising

Pesticidal RNAs

Types of mutations

http://evolution.berkeley.edu/evosite/evo101/IIIC3aTypes.shtml

Substitution Insertion Deletion

Genome editing: mutations in rice indistinguishable from spontaneous ones

Shan et al, 2013. Targeted genome modification of crop plants using a CRISPR-Cas system. Nature Biotechnology 31:686

Red=insertions, dashes=deletions

Cisgenesis

http://www.biofortified.org/2013/08/cisgenesis-new-dawn-on-food-production/

Discussion

Questions/concerns Future programming needs