Nonphytate Phosphorus Requirement and Efficacy of a Genetically Engineered Yeast Phytase for Yellow Broilers at 22- to 42-d-Old Age

An experiment was conducted to investigate the requirement of nonphytate phosphorus（nPP） and efficacy of a genetically engineered yeast phytase（PHY A） for Lingnan yellow broilers from 22-to 42-d-old age.A total of 1 320 1-d-old male chicks were randomly divided into 11 dietary treatment groups,which consisted of 4 replicate floor pens with 30 birds per pen.The control group（treatment 1） was fed with basal diet of nPP 0.08% without dicalcium phosphate or phytase supplementation.Dietary levels of nPP were 0.16,0.24,0.32,0.40,0.48,and 0.56%,respectively,for treatments 2 to 7,through addition of dicalcium phosphate（chemistry grade） to the basal diet.Diets of treatments 8 to 11 were supplemented with PHY A at 200,400 and 600 U kg-1,a commercial phytase product（PHY B） at 400 U kg-1 level,respectively.The birds in 0.32-0.56% nPP groups gained more than those of the other groups（P0.05）.The nPP supplementation significantly improved feed intake（P0.05）.The feed gain ratio was significantly decreased by 0.40% nPP diet compared to the control birds（P0.05）.The level of 0.48% nPP was required for optimum tibia development.The additions of PHY A at 400 and 600 U kg-1 level and PHY B all significantly improved ADG（P0.05）,ADFI（P0.05）,and dry defatted tibia weight（P0.05）.Similarly,the percentage of tibia ash was increased by 600 U kg-1 PHY A supplementation（P0.05）.The requirement of nPP for maximal ADG and highest percentage tibia ash both was 0.40%.The phosphorus equivalency value of PHY A was estimated as 685 U kg-1 for male yellow broilers of 22-to 42-d-old age.

Biodegradation of azo dyes by genetically engineered azoreductase

A azoreductase gene with 537 bp was obtained by PCR amplification from Rhodobacter sphaeroides AS1 1737 The enzyme, with a molecular weight of 18 7 kD, was efficiently expressed in Escherichia coli and its biodegradation characteristics for azo dyes were investigated. Furthermore, the reaction kinetics and mechanism of azo dyes catalyzed by the genetically engineered azoreductase were studied in detail. The presence of a hydrazo-intermediate was identified, which provided a convincing evidence for the assumption that azo dyes were degraded via an incomplete reduction stage.

Genetically Engineered Corn Rootworm Resistance: Potential for Reduction of Human Health Effects From Pesticides

Objective and Methods Insecticide use, grower preferences regarding genetically engineered (GE) corn resistant to com rootworm (CRW), and the health effects of using various CRW insecticides (organophosphates, pyrethroids, fipronil and carbamates) are reviewed for current and future farm practices. Results Pest damage to corn has been reduced only one-third by insecticide applications. Health costs from insecticide use appear significant, but costs attributable to CRW control are not quantifiable from available data. Methods reducing health-related costs of insecticide-based CRW control should be evaluated. As a first step, organophosphate insecticide use has been reduced as they have high acute toxicity and risk of long-term neurological consequences. A second step is to use agents which more specifically target the CRW. Conclusion Whereas current insecticides may be poisonous to many species of insects, birds, mammals and humans, a protein derived from Bacillus thurigiensis and produced in plants via genetic modification can target the specific insect of CRW (Coleoptra), sparing other insect and non-insect species from injury.

“HoneySweet”Plum-A Valuable Genetically Engineered Fruit-Tree Cultivar

"HoneySweet" is a plum variety developed through genetic engineering to be highly resistant to plum pox potyvirus (PPV) the causal agent of sharka disease that threatens stone-fruit industries world-wide, and most specifically in Europe. Field testing for over 15 years in Europe has demonstrated the stable and durable PPV resistance of “HoneySweet”. Resistance is based on gene silencing whereby the inserted gene induces a natural plant defense mechanism against viruses. This resistance has been transferred to seedlings through cross-hybridization as a single locus dominant trait making it useful as a parent for developing new plum varieties for specific growing areas and markets. “HoneySweet” plums are of high quality and compare well to the quality and nutritional value of conventional plums. “HoneySweet” demonstrates the utilization of genetic engineering to provide safe and effective solutions to important agricultural challenges facing growers, and ultimately consumers.

A genetically engineered neuronal membrane-based nanotoxoid elicits protective immunity against neurotoxins

Given their dangerous effects on the nervous system,neurotoxins represent a significant threat to public health.Various therapeutic approaches,including chelating agents,receptor decoys,and toxin-neutralizing antibodies,have been explored.While prophylactic vaccines are desirable,it is oftentimes difficult to effectively balance their safety and efficacy given the highly dangerous nature of neurotoxins.To address this,we report here on a nanovaccine against neurotoxins that leverages the detoxifying properties of cell membrane-coated nanoparticles.A genetically modified cell line with constitutive overexpression of theα7 nicotinic acetylcholine receptor is developed as a membrane source to generate biomimetic nanoparticles that can effectively and irreversibly bind toα-bungarotoxin,a model neurotoxin.This abrogates the biological activity of the toxin,enabling the resulting nanotoxoid to be safely delivered into the body and processed by the immune system.When co-administered with an immunological adjuvant,a strong humoral response againstα-bungarotoxin is generated that protects vaccinated mice against a lethal dose of the toxin.Overall,this work highlights the potential of using genetic modification strategies to develop nanotoxoid formulations against various biological threats.

Genetically engineered bacterial-like particles induced specific cellular and humoral immunity as effective tick-borne encephalitis virus vaccine

Tick-borne encephalitis(TBE)is a natural focal disease with fatal encephalitis induced by tick-borne encephalitis virus(TBEV),seriously threatening human and public health.Protection of TBE depends on vaccination with inactivated vaccine,which requires high cost and multiple immunizations.Here,we construct genetically engineered bacterial-like particles(BLPs)as an effective TBEV vaccine with simplified immunizations and improved immune efficacy.The TBEV BLPs involve the combination of the gram-positive enhancer matrix from Lactococcus lactis,and TBEV envelope(E)protein expressed by genetically engineered recombinant baculovirus.The prepared TBEV BLPs can effectively stimulate the activation of dendritic cells to present the TBEV E proteins to T and B cells,leading to strong and durable cellular and humoral immune responses in mice.Surprisingly,the serum levels of specific IgG antibodies in mice remain about 10^(6)at 6 months after the secondary immunization.Overall,the TBEV BLPs can be used as a potent vaccine candidate,laying the foundation for developing novel TBEV genetically engineered vaccines.

Advances in Research on Genetically Engineered Plants for Metal Resistance

The engineering application of natural hyperaccumulators In removing or inactivating metal pollutants from soil and surface water In field trials mostly presents the insurmountable shortcoming of low efficiency owing to their little biomass and slow growth. Based on further understanding of the molecular mechanism of metal uptake, translocation, and also the separation, identification, and cloning of some related functional genes, this article highlights and summarizes In detail the advances in research on transgenlc techniques, such as Agrobacterlurn tumefaciens-medlated transformation and particle bombardment, in breeding of plants for metal resistance and accumulation, and points out that deepening the development of transgenlc plants Is one of the efficient approaches to improving phytoremedlatlon efficiency of metalcontaminated environments. From the viewpoint of sustainable development, governments should strengthen support to the development of genetic engineering for metal resistance and accumulation In plants.

Arsenic removal from contaminated soil via biovolatilization by genetically engineered bacteria under laboratory conditions

In Rhodopseudomonas palustris,an arsM gene,encoding bacterial and archaeal homologues of the mammalian Cyt19 As（III） S-adenosylmethionine methytransferase,was regulated by arsenicals.An expression of arsM was introduced into strains for the methylation of arsenic.When arsM was expressed in Sphingomonas desiccabilis and Bacillus idriensis,it had 10 folds increase of methyled arsenic gas compared to wild type in aqueous system.In soil system,about 2.2%–4.5% of arsenic was removed by biovolatilization during 30 days.This study demonstrated that arsenic could be removed through volatilization from the contaminated soil by bacteria which have arsM gene expressed.These results showed that it is possible to use microorganisms expressing arsM as an inexpensive,efficient strategy for arsenic bioremediation from contaminated water and soil.

Clinical trial perspective for adult and juvenile Huntington's disease using genetically-engineered mesenchymal stem cells

Progress to date from our group and others indicate that using genetically-engineered mesenchymal stem cells（MSC） to secrete brain-derived neurotrophic factor（BDNF） supports our plan to submit an Investigational New Drug application to the Food and Drug Administration for the future planned Phase 1 safety and tolerability trial of MSC/BDNF in patients with Huntington＇s disease（HD）. There are also potential applications of this approach beyond HD. Our biological delivery system for BDNF sets the precedent for adult stem cell therapy in the brain and could potentially be modified for other neurodegenerative disorders such as amyotrophic lateral sclerosis（ALS）, spinocerebellar ataxia（SCA）, Alzheimer＇s disease, and some forms of Parkinson＇s disease. The MSC/BDNF product could also be considered for studies of regeneration in traumatic brain injury, spinal cord and peripheral nerve injury. This work also provides a platform for our future gene editing studies, since we will again use MSCs to deliver the needed molecules into the central nervous system.

Genetically engineered materials:Proteins and beyond

Information-rich molecules provide opportunities for evolution.Genetically engineered materials are superior in that their properties are coded within genetic sequences and could be fine-tuned.In this review,we elaborate the concept of genetically engineered materials(GEMs)using examples ranging from engineered protein materials to engineered living materials.Proteinbased materials are the materials of choice by nature.Recent progress in protein engineering has led to opportunities to tune their sequences for optimal material performance.Proteins also play a central role in living materials where they act in concert with other biological components as well as nonbiological cofactors,giving rise to living features.While the existing GEMs are often limited to those constructed by building blocks of biological origin,being genetically engineerable does not preclude nonbiologic or synthetic materials,the latter of which have yet to be fully explored.

Rice-wheat comparative genomics:Gains and gaps

Rice and wheat provide nearly 40%of human calorie and protein requirements.They share a common ancestor and belong to the Poaceae(grass)family.Characterizing their genetic homology is crucial for developing new cultivars with enhanced traits.Several wheat genes and gene families have been characterized based on their rice orthologs.Rice–wheat orthology can identify genetic regions that regulate similar traits in both crops.Rice–wheat comparative genomics can identify candidate wheat genes in a genomic region identified by association or QTL mapping,deduce their putative functions and biochemical pathways,and develop molecular markers for marker-assisted breeding.A knowledge of gene homology facilitates the transfer between crops of genes or genomic regions associated with desirable traits by genetic engineering,gene editing,or wide crossing.

Drought-Tolerant Rice at Molecular Breeding Eras:An Emerging Reality

Rice(Oryza sativa L.)stands as the most significantly influential food crop in the developing world,with its total production and yield stability affected by environmental stress.Drought stress impacts about 45%of the world’s rice area,affecting plants at molecular,biochemical,physiological,and phenotypic levels.The conventional breeding method,predominantly employing single pedigree selection,has been widely utilized in breeding numerous drought-tolerant rice varieties since the Green Revolution.With rapid progress in plant molecular biology,hundreds of drought-tolerant QTLs/genes have been identified and tested in rice crops under both indoor and field conditions.Several genes have been introgressed into elite germplasm to develop commercially accepted drought-tolerant varieties,resulting in the development of several drought-tolerant rice varieties through marker-assisted selection and genetically engineered approaches.This review provides up-to-date information on proof-of-concept genes and breeding methods in the molecular breeding era,offering guidance for rice breeders to develop drought-tolerant rice varieties.

Enemies atpeace:Recentprogressin Agrobacterium-mediated cereal transformation

Agrobacterium tumefaciens mediated plant transformation is a versatile tool for plant genetic engineering following its discovery nearly half a century ago.Numerous modifications were made in its application to increase efficiency,especially in the recalcitrant major cereals plants.Recent breakthroughs in transformation efficiency continue its role as a mainstream technique in CRISPR/Cas-based genome editing and gene stacking.These modifications led to higher transformation frequency and lower but more stable transgene copies with the capability to revolutionize modern agriculture.In this review,we provide a brief overview of the history of Agrobacterium-mediated plant transformation and focus on the most recent progress to improve the system in both the Agrobacterium and the host recipient.A promising future for transformation in biotechnology and agriculture is predicted.

Coupled strategy based on regulator manipulation and medium optimization empowers the biosynthetic overproduction of lincomycin

The biosynthesis of bioactive secondary metabolites,specifically antibiotics,is of great scientific and economic importance.The control of antibiotic production typically involves different processes and molecular mechanism.Despite numerous efforts to improve antibiotic yields,joint engineering strategies for combining genetic manipulation with fermentation optimization remain finite.Lincomycin A(Lin-A),a lincosamide antibiotic,is industrially fermented by Streptomyces lincolnensis.Herein,the leucine-responsive regulatory protein(Lrp)-type regulator SLCG_4846 was confirmed to directly inhibit the lincomycin biosynthesis,whereas indirectly controlled the transcription of SLCG_2919,the first reported repressor in S.lincolnensis.Inactivation of SLCG_4846 in the high-yield S.lincolnensis LA219X(LA219XΔ4846)increases the Lin-A production and deletion of SLCG_2919 in LA219XΔ4846 exhibits superimposed yield increment.Given the effect of the double deletion on cellular primary metabolism of S.lincolnensis,Plackett-Burman design,steepest ascent and response surface methodologies were utilized and employed to optimize the seed medium of this double mutant in shake flask,and Lin-A yield using optimal seed medium was significantly increased over the control.Above strategies were performed in a 15-L fermenter.The maximal yield of Lin-A in LA219XΔ4846-2919 reached 6.56 g/L at 216 h,55.1%higher than that in LA219X at the parental cultivation(4.23 g/L).This study not only showcases the potential of this strategy to boost lincomycin production,but also could empower the development of high-performance actinomycetes for other antibiotics.

Trehalose:A sugar molecule involved in temperature stress management in plants

Trehalose(Tre)is a non-reducing disaccharide found in many species,including bacteria,fungi,invertebrates,yeast,and even plants,where it acts as an osmoprotectant,energy source,or protein/membrane protector.Despite relatively small amounts in plants,Tre concentrations increase following exposure to abiotic stressors.Trehalose-6-phosphate,a precursor of Tre,has regulatory functions in sugar metabolism,crop production,and stress tolerance.Among the various abiotic stresses,temperature extremes(heat or cold stress)are anticipated to impact crop production worldwide due to ongoing climate changes.Applying small amounts of Tre can mitigate negative physiological,metabolic,and molecular responses triggered by temperature stress.Trehalose also interacts with other sugars,osmoprotectants,amino acids,and phytohormones to regulate metabolic reprogramming that underpins temperature stress adaptation.Transformed plants expressing Tre-synthesis genes accumulate Tre and show improved stress tolerance.Genome-wide studies of Tre-encoding genes suggest roles in plant growth,development,and stress tolerance.This review discusses the functions of Tre in mitigating temperature stress—highlighting genetic engineering approaches to modify Tre metabolism,crosstalk,and interactions with other molecules—and in-silico approaches for identifying novel Tre-encoding genes in diverse plant species.We consider how this knowledge can be used to develop temperature-resilient crops essential for sustainable agriculture.

Recent progress in engineering Clostridium autoethanogenum to synthesize the biochemicals and biocommodities

Excessive mining and utilization fossil fuels has led to drastic environmental consequences,which will contribute to global warming and cause further climate change with severe consequences for the human population.The magnitude of these challenges requires several approaches to develop sustainable alternatives for chemicals and fuels production.In this context,biological processes,mainly microbial fermentation,have gained particular interest.For example,autotrophic gas-fermenting acetogenic bacteria are capable of converting CO,CO_(2) and H_(2) into biomass and multiple metabolites through Wood-Ljungdahl pathway,which can be exploited for large-scale fermentation processes to sustainably produce bulk biochemicals and biofuels(e.g.acetate and ethanol)from syngas.Clostridium autoethanogenum is one representative of these chemoautotrophic bacteria and considered as the model for the gas fermentation.Recently,the development of synthetic biology toolbox for this strain has enabled us to study and genetically improve their metabolic capability in gas fermentation.In this review,we will summarize the recent progress involved in the understanding of physiological mechanism and strain engineering for C.autoethanogenum,and provide our perspectives on the future development about the basic biology and engineering biology of this strain.

Cell cycle exit and neuronal differentiation 1-engineered embryonic neural stem cells enhance neuronal differentiation and neurobehavioral recovery after experimental traumatic brain injury

Our previous study showed that cell cycle exit and neuronal differentiation 1(CEND1)may participate in neural stem cell cycle exit and oriented differentiation.However,whether CEND1-transfected neural stem cells can improve the prognosis of traumatic brain injury remained unclear.In this study,we performed quantitative proteomic analysis and found that after traumatic brain injury,CEND1 expression was downregulated in mouse brain tissue.Three days after traumatic brain injury,we transplanted CEND1-transfected neural stem cells into the area surrounding the injury site.We found that at 5 weeks after traumatic brain injury,transplantation of CEND1-transfected neural stem cells markedly alleviated brain atrophy and greatly improved neurological function.In vivo and in vitro results indicate that CEND1 overexpression inhibited the proliferation of neural stem cells,but significantly promoted their neuronal differentiation.Additionally,CEND1 overexpression reduced protein levels of Notch1 and cyclin D1,but increased levels of p21 in CEND1-transfected neural stem cells.Treatment with CEND1-transfected neural stem cells was superior to similar treatment without CEND1 transfection.These findings suggest that transplantation of CEND1-transfected neural stem cells is a promising cell therapy for traumatic brain injury.This study was approved by the Animal Ethics Committee of the School of Biomedical Engineering of Shanghai Jiao Tong University,China(approval No.2016034)on November 25,2016.

Plant biotechnology:a case study of Bacillus thuringiensis(Bt) and its application to the future of genetic engineered trees

Agricultural productivity may be raised in a sustainable way by many different technologies such as biological fertilizers, soil and water conservation, biodiversity conservation, improved pest control, and changes in land ownership and distribution. Of these measures, biotechnology applications probably hold the most promise in augmenting conventional agricultural productivity, because biotechnology applications give not only the need to increase production, but also protect the environment and conserving natural resources for future generations. Biotechnology applications will have the possibilities to increase productivity and food availability through better agronomic performance of new varieties, including resistance to pests; rapid multiplication of disease-free plants; ability to obtain natural plant products using tissue culture; diagnosis of diseases of plants and livestock; manipulation of reproduction methods increasing the efficiency of breeding; and the provision of incentives for greater participation by the private sector through investments. Insect resistance through the transfer of a gene for resistance fromBacillus thuringiensis (Bt) is one of the most advanced biotechnology applications already being commercialized in many parts of the world. This paper reviews the development and the status ofBt technology and application ofBt transgenic plants in current agriculture, and discusses specific issues related to the transfer of the technology to the future of genetic engineered trees with emphasis on conifers. Key words Agricultural productivity - Bacillus thuringiensis - Genetic engineering - Insect resistance - Trees CLC number Q812 - S763.306 Document code A Biography: Tang Wei (1964-), male, Ph. Doctor, Research associate, Department of Biology, Howell Science Complex, East Carelina University, Greenville, NC 27858-4353, USA.Responsible editor: Chal Ruihai

Awareness and Perception of Genetic Modification among Science and Technical Vocational Teachers in Guyana： Focusing on Genetically Modified Foods

A study was conducted to determine the awareness and perception of biotechnology focusing on genetically modified foods among public secondary school science and technical vocational teachers in Guyana. A questionnaire was administered to 228 randomly selected teachers of 42 schools in six administrative regions of Guyana, representing about 90% of the population. The results revealed that there was a low level of awareness among the teachers： those who were knowledgeable about the subject were mainly Biology, Agricultural Science and Integrated Science teachers. Most teachers （almost 90%） indicated that the public is not receiving adequate information about genetically-modified foods and opined that the television should be the main medium to provide information. The study also revealed that teachers felt that ethical, religious and social issues should be considered when applying the technology. This view did not vary based on qualifications, years in the profession or subjects taught. Genetic modification was more acceptable to plant-based than animal-based foods, although they seemed ambivalent as to whether genetically modified foods can be harmful to their health. The implications of these findings are that more teachers in various subject areas should be informed about emerging issues in sciences to enable them to better analyze the subject matter, transfer information to the students, and form attitudes and opinions based on facts.

Optimization of Coenzyme Q10Production Procedure from Genetic Engineered Rhodobacter sphaeroides Overexpressing UbiG

In the present study, single factors including fermentation temperature, inoculate amount, fermentation duration, and ratio of fermentation medium volume to total flask volume(dissolved oxygen tension) were optimized for enhancing the production of coenzyme Q10 from genetic engineered Rhodobacter sphaeroides overexpressing UbiG. The experimental results suggested that optimal single factors were: inoculate amount 2%, fermentation temperature 30 ℃, fermentation duration 48 h, and ratio of fermentation medium volume to total flask volume 80%. The present study will promote the large scale production of CoQ10 from microorganisms.