A critical exploration of permaculture’s global role in sustainable development

Despite emerging literature on Permaculture as a sustainable solution-based approach to the environmental, economic and social consequences of non-sustainable global growth, many accounts infer it is a political practice working against many corporate and bureaucratic forms of power. Using examples of Permaculture from a global context, such as ‘Omah Lor’ - a demonstration hub situated in Java Indonesia, Incredible farm in the UK, and various applicable advances in technological design, this paper focuses on the practices and key drivers of Permaculture in order to illustrate that the movement is, potentially, a cohesive component in assisting policy makers moving towards a sustainable future. Alternatively, this paper draws on ethnographic data to focus attention upon the ‘mainstreaming’ of ‘regenerative activism’, arguing that guiding core principles (and the associated impacts of these principles) alongside the foundational value ethics within Permaculture are important considerations for policymakers who share a global common discourse in sustainable development. As yet, this point is still widely underacknowledged at policy level

Testing an "in-out" targeting procedure for making subtle genomic modifications in mouse embryonic stem cells.

We have introduced a 4-bp insertion into the hypoxanthine phosphoribosyltransferase (HPRT) gene of a mouse embryonic stem (ES) cell line by using an "in-out" targeting procedure. During the in step, a homologous integration reaction, we targeted a correcting plasmid to a partially deleted hprt- locus by using an integrating vector that carried a 4-bp insertion in the region of DNA homologous to the target locus. HPRT+ recombinants were isolated by direct selection in hypoxanthine-aminopterin-thymidine (HAT) medium. The HATr cell lines were then grown in medium containing 6-thioguanine (6-TG) to select for hprt- revertants resulting from the excision of the integrated vector sequences. The revertants were examined by Southern blot hybridization to determine the accuracy of this out reaction and the frequency of retaining the 4-bp modification in the genome. Of the 6-TGr colonies examined, 88% had accurately excised the integrated vector sequences; 19 of 20 accurate revertants retained the 4-bp insertion in the resulting hprt- gene. We suggest a scheme for making the in-out targeting procedure generally useful to modify the mammalian genome

Generating mice with targeted mutations.

Journal ArticleMutational analysis is one of the most informative approaches available for the study of complex biological processes. It has been particularly successful in the analysis of the biology of bacteria, yeast, the nematode worm Caenorhabditis elegans and the fruit fly Drosophila melanogaster. Extension of this approach to the mouse, through informative, was far less successful relative to what has been achieved with these simpler model organisms. This is because it is not numerically practical in mice to use random mutagenesis to isolate mutations that affect a specified biological process of interest. Nonetheless, biological phenomena such as a sophisticated immune response, cancer, vascular disease or higher-order cognitive function, to mention just a few, must analyzed in organisms that show such phenomena, and for this reason geneticists and other researchers have turned to the mouse. Gene targeting, the means for creating mice with designed mutations in almost any gene, was developed as an alternative to the impractical use of random mutgenesis for pursing genetic analysis in the mouse. Now gene targeting has advanced the genomic manipulations possible in mice to a level that can be matched only in far simple organisms such as bacteria and yeast

Unexpected relationships between four large deletions in the human β-globin gene cluster.

Two independent gamma delta beta-thalassemias are each associated with large deletions. We show, by comparing DNA sequences, that the deletions are due to non-homologous DNA exchanges. The 5' breakpoints are located approximately the same distance apart and in the same order along the DNA as their 3' breakpoints. Two independent cases of hereditary persistence of fetal hemoglobin, also involving large deletions, show the same unexpected relationship between their 5' and 3' breakpoints. This relationship is most simply explained if, within each pair, the deletions are of approximately the same length. The results suggest that the four deletions were generated by a common mechanism. Perhaps their 5' and 3' breakpoints are physically close in the nucleus, although far apart on the linear DNA

Lethal thalassemia after insertional disruption of the mouse major adult beta-globin gene.

Thalassemias are hereditary anemias caused by mutations that disturb the normal 1:1 balance of a- and β-globin chains that form hemoglobin. We have disrupted the major adult β-globin gene (b1) in mouse embryonic stem cells by using homologous recombination to insert selectable sequences into the gene. Mice homozygous for this insertional disruption of the b1 gene (Hbbth-1/Hbbth-2) are severely anemic and die perinatally. In contrast, ≃60% of mice homozygous for deletion of the same gene (Hbbth-1/Hbbth-1) survive to adulthood and are much less anemic [Skow, L. C., Burkhart, B. A., Johnson, F. M., Popp, R. A., Goldberg, S. Z., Anderson, W. F., Barnett, L. B. & Lewis, S. E. (1983) Cell 34, 1043-1052].Thalassemias are hereditary anemias caused by mutations that disturb the normal 1:1 balance of a- and β-globin chains that form hemoglobin. We have disrupted the major adult β-globin gene (b1) in mouse embryonic stem cells by using homologous recombination to insert selectable sequences into the gene. Mice homozygous for this insertional disruption of the b1 gene (Hbbth-1/Hbbth-2) are severely anemic and die perinatally. In contrast, ≃60% of mice homozygous for deletion of the same gene (Hbbth-1/Hbbth-1) survive to adulthood and are much less anemic [Skow, L. C., Burkhart, B. A., Johnson, F. M., Popp, R. A., Goldberg, S. Z., Anderson, W. F., Barnett, L. B. & Lewis, S. E. (1983) Cell 34, 1043-1052]

Adrenomedullin gene expression differences in mice do not affect blood pressure but modulate hypertension-induced pathology in males

Adrenomedullin (AM) is a potent vasodilator peptide in plasma at picomolar levels. Polymorphisms in the human AM gene have been associated with genetic predisposition to diabetic nephropathy and proteinuria with essential hypertension, and numerous studies have demonstrated that endogenous AM plays a role in protecting the heart and kidneys from fibrosis resulting from cardiovascular disease. Elevated plasma levels of AM are associated with pregnancy and sepsis and with cardiovascular stress and hypertension. However, there are no reports of the effects of genetic differences in the expression of the endogenous AM gene and of gender on blood pressure in these circumstances or on the pathological changes accompanying hypertension. To address these questions, we have generated mice having genetically controlled levels of AM mRNA ranging from ≈50% to ≈140% of wild-type levels. These modest changes in AM gene expression have no effect on basal blood pressure. Although pregnancy and sepsis increase plasma AM levels, genetically reducing AM production does not affect the transient hypotension that occurs during normal pregnancy or that is induced by treatment with lipopolysaccharide. Nor does the reduction of AM affect chronic hypertension caused by a renin transgene. However, 50% normal expression of AM enhances cardiac hypertrophy and renal damage in male, but not female, mice with a renin transgene. These observations suggest that the effect of gender on the role of AM in counteracting cardiovascular damage in humans merits careful evaluation

Cotransformation and gene targeting in mouse embryonic stem cells.

We have investigated cotransformation in mammalian cells and its potential for identifying cells that have been modified by gene targeting. Selectable genes on separate DNA fragments were simultaneously introduced into cells by coelectroporation. When the introduced fragments were scored for random integration, 75% of the transformed cells integrated both fragments within the genome of the same cell. When one of the cointroduced fragments was scored for integration at a specific locus by gene targeting, only 4% of the targeted cells cointegrated the second fragment. Apparently, cells that have been modified by gene targeting with one DNA fragment rarely incorporate a second DNA fragment. Despite this limitation, we were able to use the cotransformation protocol to identify targeted cells by screening populations of colonies that had been transformed with a cointroduced selectable gene. When hypoxanthine phosphoribosyltransferase (hprt) targeting DNA was coelectroporated with a selectable neomycin phosphotransferase (neo) gene into embryonic stem (ES) cells, hprt-targeted colonies were isolated from the population of neo transformants at a frequency of 1 per 70 G418-resistant colonies. In parallel experiments with the same targeting construct, hprt-targeted cells were found at a frequency of 1 per 5,500 nonselected colonies. Thus, an 80-fold enrichment for targeted cells was observed within the population of colonies transformed with the cointroduced DNA compared with the population of nonselected colonies. This enrichment for targeted cells after cotransformation should be useful in the isolation of colonies that contain targeted but nonselectable gene alterations