Od PET lahví k dobrotám

The treatment of waste PET bottles has become a pressing global issue over the last few decades, and many scientific teams are currently working on solutions to it. There are many different approaches of how to solve this problem. The present article outlines the possibility to process terephthalic acid, which is the hydrolysis product of polyethylene terephthalate, into vanillin, a compound widely used in the food industry. The work of British scientists who have succeeded in using genetic modification to produce a strain of E. coli RARE_pVanX capable of processing polyethylene terephthalate hydrolysates to the desired vanillin is presented in a broader context.

Genetic Modification and Application in Cassava, Sweetpotato and Yams

Cassava (Manihot esculenta Crantz), sweetpotato (Ipomoea batatas) and yams (Dioscorea spp.) are important root and tuber crops grown for food, feed and various industrial applications. However, their genetic gain potentials are limited by breeding and genetic bottlenecks for improvement of many desired traits. This book chapter covers the applications and potential benefits of genetic modification in breeding selected outcrossing root and tuber crops. It assesses how improvement of selected root and tuber crops through genetic modification overcomes both the high heterozygosity and serious trait separation that occurs in conventional breeding, and contributes to timely achievement of improved target traits. It also assesses the ways genetic modification improves genetic gain in the root and tuber breeding programs, conclusions and perspectives. Conscious use of complementary techniques such as genetic modification in the root and tuber breeding programs can increase the selection gain by reducing the long breeding cycle and cost, as well as reliable exploitation of the heritable variation in the desired direction.

Genetic Modification Approaches for Parasporins Bacillus thuringiensis Proteins with Anticancer Activity

Bacillus thuringiensis (Bt) is a bacterium capable of producing Cry toxins, which are recognized for their bio-controlling actions against insects. However, a few Bt strains encode proteins lacking insecticidal activity but showing cytotoxic activity against different cancer cell lines and low or no cytotoxicity toward normal human cells. A subset of Cry anticancer proteins, termed parasporins (PSs), has recently arisen as a potential alternative for cancer treatment. However, the molecular receptors that allow the binding of PSs to cells and their cytotoxic mechanisms of action have not been well established. Nonetheless, their selective cytotoxic activity against different types of cancer cell lines places PSs as a promising alternative treatment modality. In this review, we provide an overview of the classification, structures, mechanisms of action, and insights obtained from genetic modification approaches for PS proteins.

Genetic Modification of Limbal Stem Cells to Decrease Allogeneic Immune Responses

Limbal stem cell (LSC) transplantation is the only efficient treatment for patients affected by LSC deficiency (LSCD). Allogeneic LSC transplantation is one of the most successful alternative for patients with bilateral LSCD. Nevertheless, the high variability of the human leukocyte antigens (HLA) remains a relevant obstacle to long-term allogeneic graft survival. This study characterized the immunologic properties of LSCs and proposed a genetic engineering strategy to reduce the immunogenicity of LSCs and of their derivatives. Hence, LSC HLA expression was silenced using lentiviral vectors encoding for short hairpin (sh) RNAs targeting β2-microglobulin (β2M) or class II major histocompatibility complex transactivator (CIITA) to silence HLA class I and II respectively. Beside the constitutive expression of HLA class I, LSCs showed the capability to upregulate HLA class II expression under inflammatory conditions. Furthermore, LSCs demonstrated the capability to induce T-cell mediated immune responses. LSCs phenotypical and functional characteristics are not disturbed after genetic modification. However, HLA silenced LSC showed to prevent T cell activation, proliferation and cytotoxicity in comparison to fully HLA-expressing LSCs. Additionally; HLA-silenced LSCs were protected against antibody-mediated cellular-dependent cytotoxicity. Our data is a proof-of-concept of the feasibility to generate low immunogenic human LSCs without affecting their typical features. The use of low immunogenic LSCs may support for long-term survival of LSCs and their derivatives after allogeneic transplantation.

Using Lentivirus and CRISPR to Modify Cattle Embryonic Genes

<p>Developing transgenic livestock has become popular in recent years after advances in the field of genetic editing. Cattle are one of the main exports in New Zealand and are a prime target for new genetic editing tools. Applications of genetic editing in cattle can extend to increases in production, and elimination of disease genes. Due to its ease of use, CRISPR/Cas9 has become one of the most popular methods of editing genes, hence this was employed in the research. Cattle embryos in culture are very sensitive to environmental changes and for this reason, a delivery vector is necessary to deliver the genetic material as traditional transfection methods cause high rates of embryo death. The zona pellucida, a glycoprotein coat surrounding the embryo, acts as a protective agent against viral vectors, and needed to be considered in the research. This research aimed to create a novel, high titer lentivirus particle capable of transducing bovine embryos, and causing subsequent genetic modification by integration of CRISPR/Cas9 into the genome. Using fluorescent reporters, viral transduction was monitored. The research found that after optimizing transfection protocols, high-titer lentiviral particles can be produced and can infect bovine embryos. Zona pellucida removal experiments revealed over-digestion in early stage embryos, however, this was not observed in compact morulas. Removing the zona allowed for successful transduction of bovine embryos, resulting in transgenic cells expressing eGFP. While CRISPR/Cas9 experiments were in preliminary stages, these indicated eGFP knock-out in certain eGFP-HEK293T cells. Though challenges were encountered throughout the research process, solutions were explored, and it was shown that transgenic bovine embryos using lentiviral gene delivery can be produced. This indicates the high likelihood that CRISPR/Cas9 systems can be delivered this way, inducing targeted genetic modification.</p>