Papers by Jonathan Latham
Rethinking Food and Agriculture, 2021
Abstract A key assertion in many discussions on global agriculture is the prediction of a potenti... more Abstract A key assertion in many discussions on global agriculture is the prediction of a potential future global food production deficit: the challenge of “feeding the 10 billion.” The crisis narrative has in many ways been led by the UN’s Food and Agriculture Organization (FAO), whose quantitative modeling of the food system has predicted a 70% increase (now 60%) in the annual total of food needed by 2050. By examining the assumptions underlying its modeling, however, this chapter shows that FAO and other modelers have consistently underestimated actual and potential global food supplies and overestimated food demand. For example, FAO’s latest model underreports potential rice yields by approximately 7 billion persons’ worth of food. In all, this chapter estimates that, since they all use similar assumptions, at least 12.5 billion persons’ worth of food has been left out of current food models. Thus current models imply quantitative scarcity where none exists.
Good journalism examines its sources critically, it takes nothing at face value, places its topic... more Good journalism examines its sources critically, it takes nothing at face value, places its topics in a historical context, and it values above all the public interest. Such journalism is, most people agree, essential to any equitable and open system of government. These statements are, if anything, especially applicable to the science media. But while the media in general has recently taken much criticism, for trivialising news and other flaws, the science media has somehow escaped serious attention. This is unfortunate because no country in the world has a healthy science media.
Biotechnology and Genetic Engineering Reviews, 2006
Biotechnology and Genetic Engineering Reviews
The Cry toxins are a family of crystal-forming proteins produced by the bacterium Bacillus thurin... more The Cry toxins are a family of crystal-forming proteins produced by the bacterium Bacillus thuringiensis. Their mode of action is thought to be to create pores that disrupt the gut epithelial membranes of juvenile insects. These pores allow pathogen entry into the hemocoel, thereby killing the insect. Genes encoding a spectrum of Cry toxins, including Cry mutants, Cry chimaeras and other Cry derivatives, are used commercially to enhance insect resistance in genetically modified (GM) crops. In most countries of the world, such GM crops are regulated and must be assessed for human and environmental safety. However, such risk assessments often do not test the GM crop or its tissues directly. Instead, assessments rely primarily on historical information from naturally occurring Cry proteins and on data collected on Cry proteins (called 'surrogates') purified from laboratory strains of bacteria engineered to express Cry protein. However, neither surrogates nor naturally occurring Cry proteins are identical to the proteins to which humans or other nontarget organisms are exposed by the production and consumption of GM plants. To-date there has been no systematic survey of these differences. This review fills this knowledge gap with respect to the most commonly grown GM Cry-containing crops approved for international use. Having described the specific differences between natural, surrogate and GM Cry proteins this review assesses these differences for their potential to undermine the reliability of risk assessments. Lastly, we make specific recommendations for improving risk assessments.
Thesis (Ph. D.)--University of East Anglia, 1996.
Recent developments in the application of RNA interference (RNAi) to plants mean that the introdu... more Recent developments in the application of RNA interference (RNAi) to plants mean that the introduction of transgenes with defined sequences can now routinely result in the inhibition of target RNAs and therefore gene activity. Consequently, there are now greatly enhanced opportunities for the use of this technology in agriculture and speciality crops. Applications demonstrated so far include the manipulation of plant metabolism and behaviour, and resistance to pathogenic bacteria, viruses, insects, and other invertebrates. Realisation of this potential, however, will ultimately depend on the specificity with which transgene-derived RNAs act. Specificity is important within the crop plant itself but also towards exposed non-target organisms such as beneficial insects and mammals. There has been little discussion of off-target effects (OTEs) arising from plant transgenic RNAi. This review considers three classes of potential plant RNAi OTEs: (1) OTEs leading to non-specific downregula...
Many genetic engineers have long resented the regulatory procedures imposed on transgenic crop pl... more Many genetic engineers have long resented the regulatory procedures imposed on transgenic crop plants, often arguing that there is no difference between the risks arising from transgenic plants and plants bred using ‘conventional’ methods. A recent proposal calls for complete deregulation of transgenic plants that have only plant DNA inserted into their genomes (Schouten et al., 2006a,b). The term cisgenic has been coined for such plants in order to highlight the origins of the transferred DNA. Other terms for plant-derived transgenes include ‘all-native DNA’ and ‘P-DNA’ (Rommens, 2004). In this short review and analysis article, we assess whether the published data on "cisgenic" plants suggest they pose fewer biosafety risks than other types of transgenic plants. We also describe experiments that would further scientific understanding of the differences between cisgenic, transgenic and "conventionally bred" plants.
Nature, Jan 16, 2000
Sir-The existence of malnourished and hungry people has been used repeatedly in this journal and ... more Sir-The existence of malnourished and hungry people has been used repeatedly in this journal and elsewhere as a justification for biotechnology and for the production of more food 1,2. This assumption supports a main policy plank of the Rockefeller Foundation food biotechnology programme 2 and other major international and charitable institutions. Yet there are good reasons to be sceptical of the equation "more food equals less hunger". The world produces more than enough food at present to feed everyone, but nevertheless many people still starve or are malnourished 1-3. As economist and Nobel laureate Amartya Sen has pointed out, it is poverty, not a physical shortage of food, that is the primary cause of hunger in the modern world 4. The political and economic reasons don't change: the amount of food that Ireland, for example, exported to Britain during the potato famine of 1845-46 would have been sufficient to feed those who starved. The root cause of the 1974 Bangladesh famine was a flood that displaced people from their jobs; more food was produced that year in Bangladesh than in surrounding years, yet-unable to earn money to buy it-up to 1.5 million people starved to death 4. Partial solutions such as local production of food, as suggested by Conway and Toenniessen 2 , cannot circumvent economic reality. Even the World Bank has concluded that the problem of hunger can only be solved by "redistributing purchasing power" to the hungry 5. What about the state of food supplies in, say, 2040, when it is predicted that there will be ten billion people compared with today's six billion? In absolute terms, the world already produces enough food to feed ten billion people-it's just that most of it is fed to animals (this accounts for 80% of all arable crops in the United States, a figure close to the world average 6). If the area of arable land devoted to crops for human consumption were doubled to 40%, this need not drastically affect supplies of meat or dairy produce, since farm animals also eat other, non-crop foods such as grass in the summer, silage and hay in the winter. Clearly, what is missing is the "purchasing power" of the poor.
Genetics, 1999
Eukaryotic mRNAs that contain premature stop codons are degraded more rapidly than their wild-typ... more Eukaryotic mRNAs that contain premature stop codons are degraded more rapidly than their wild-type counterparts, a phenomenon termed "nonsense-mediated mRNA decay" (NMD) or "mRNA surveillance." Functions of six previously described Caenorhabditis elegans genes, smg-1 through smg-6, are required for NMD. Whereas nonsense mutant mRNAs are unstable in smg(+) genetic backgrounds, such mRNAs have normal stability in smg(-) backgrounds. Previous screens for smg mutations have likely not identified all genes involved in NMD, but efforts to identify additional smg genes are limited by the fact that almost 90% of smg mutations identified in genome-wide screens are alleles of smg-1, smg-2, or smg-5. We describe a modified screen for smg mutations that precludes isolating alleles of smg-1, smg-2, and smg-5. Using this screen, we have identified and cloned smg-7, a previously uncharacterized gene that we show is required for NMD. smg-7 is predicted to encode a novel protein ...
Virology, 1992
Mutants of the monopartite geminivirus beet curly top virus have been screened for infectivity an... more Mutants of the monopartite geminivirus beet curly top virus have been screened for infectivity and symptom development in Nicotiana benthamiana and Beta vulgaris, for replication competence in N. benthamiana leaf discs, and for transmission by the leafhopper Circulifer tenehs. Disruption of open reading frame (ORF) V2 by the introduction of a termination codon resulted in symptomless infection of N. benthamiana associated with low levels of virus and reduced single-stranded (ss) DNA and prevented systemic infection of B. vulgaris. Reduced levels of ssDNA were produced by the mutant in N. benthamiana leaf discs, suggesting that V2 affects the synthesis or accumulation of this viral DNA form. Mutants in which ORF C2 had been truncated by the introduction of termination codons or by frame-shifting remained highly infectious and induced severe symptoms in both N. benthamiana and B. vulgaris. Similarly, a mutant containing a termination codon within ORF C3 was highly infectious and induced severe symptoms in N. benthamiana although infectivity in B. vulgaris was greatly reduced, symptoms were extremely mild, and virus levels were low. A synergistic effect of a double mutation in ORFs C2 and C3, manifested by the inability of mutants to systemically infect N. benthamiana and the production of reduced amounts of ssDNA in N. benthamiana leaf discs, suggests that both ORFs are functional in this host. A mutant containing a termination codon within the 5'terminus of ORF C4 produced severe symptoms in both N. benthamiana and B. vulgaris resembling those induced by wild-type virus. Comparison with the phenotypes of previously characterized ORF C4 mutants suggests that a conserved core sequence of this ORF is an important symptom determinant. ORF C2, C3, and C4 mutants produced virus particles and were transmitted by C. tenellus, eliminating agroinoculation as a contributory factor to the mutant phenotypes. Our results are compared with those derived from mutagenesis studies on related bipartite geminiviruses.
Virology, 1993
The genome of the geminivirus beet curly top virus (BCTV) consists of a single circular DNA conta... more The genome of the geminivirus beet curly top virus (BCTV) consists of a single circular DNA containing overlapping open reading frames (ORFs) located on both the virion-sense and complementary-sense DNA strands. To investigate the expression of these ORFs, RNA extracted from infected Nicotiana benthamiana and Beta vulgaris has been examined for the presence of viral transcripts. An abundant 1.1-kb virion-sense polyadenylated RNA and four complementary-sense polyadenylated RNAs of 1.7, 1.5, 1.3, and 0.7 kb have been identified by northern blot hybridization, confirming the bidirectional transcription strategy implied by the arrangement of ORFs. We previously demonstrated that two overlapping virion-sense ORFs are involved in coat protein synthesis (ORF V1) and viral single-stranded DNA accumulation (ORF V2). Mutants of a third virion-sense ORF (ORF V3), located upstream and overlapping ORFs V1 and V2, retain the ability to replicate efficiently in N. benthamiana leaf discs but produce an asymptomatic infection in N. benthamiana and B. vulgaris at low frequency, associated with reduced levels of viral DNA compared to wild-type infection. Our data support the recent suggestion that ORF V3 participates in virus movement. The 1.1 kb virion-sense RNA comprises a population of overlapping transcripts with 5' termini suitably positioned for the expression of ORFs V1, V2, and V3. The overlapping arrangement of the transcripts and juxtaposition of putative regulatory elements could provide a means for the temporal control of virion-sense gene expression.
The Plant Journal, 1997
... Just as small tumour viruses have proved invaluable for the analysis of host gene regulation ... more ... Just as small tumour viruses have proved invaluable for the analysis of host gene regulation and the control of cell proliferation in animals (reviewed by Conzen and Cole, 1994; Huibregtse and Scheffner ... For correspondence (fax +1603 456844; e-mail John.Stanley@BBSRC ...
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Papers by Jonathan Latham