Genetically modified pigs:Emerging animal models for hereditary hearing loss

Hereditary hearing loss(HHL),a genetic disorder that impairs auditory function,significantly affects quality of life and incurs substantial economic losses for society.To investigate the underlying causes of HHL and evaluate therapeutic outcomes,appropriate animal models are necessary.Pigs have been extensively used as valuable large animal models in biomedical research.In this review,we highlight the advantages of pig models in terms of ear anatomy,inner ear morphology,and electrophysiological characteristics,as well as recent advancements in the development of distinct genetically modified porcine models of hearing loss.Additionally,we discuss the prospects,challenges,and recommendations regarding the use pig models in HHL research.Overall,this review provides insights and perspectives for future studies on HHL using porcine models.

Development of oncolytic virotherapy:from genetic modification to combination therapy

Oncolytic virotherapy(OVT)is a novel form of immunotherapy using natural or genetically modified viruses to selectively replicate in and kill malignant cells.Many genetically modified oncolytic viruses(OVs)with enhanced tumor targeting,antitumor efficacy,and safety have been generated,and some of which have been assessed in clinical trials.Combining OVT with other immunotherapies can remarkably enhance the antitumor efficacy.In this work,we review the use of wild-type viruses in OVT and the strategies for OV genetic modification.We also review and discuss the combinations of OVT with other immunotherapies.

Developments in genetic modification of cattle and implications for regulation, safety and traceability

Genetic modification techniques,in particular novel gene editing technologies,hold the yet unfulfilled promise of altering genetic traits in farm animals more efficiently than by crossbreeding,allowing for a more rapid development of new cattle breeds with distinct traits.Gene editing technologies allow for the directed alteration of specific traits and thereby have the potential to enhance,for instance,disease resilience,production yield and the production of desired substances in milk.The potential implications of these technological advancements,which are often combined with animal cloning methods,are discussed both for animal health and for consumer safety,also with consideration of available methods for the detection and identification of the related products in the food supply chain.Finally,an overview is provided of current regulatory approaches in the European Union(EU)and major countries exporting beef to the EU,for products from animals bred through established practices as well as modern biotechnologies.

Generation of genetically modified mice using CRISPR/Cas9 and haploid embryonic stem cell systems

With the development of high-throughput sequencing technology in the post-genomic era, researchers have concentrated their efforts on elucidating the relationships between genes and their corresponding functions. Recently, important progress has been achieved in the generation of genetically modified mice based on CRISPR/Cas9 and haploid embryonic stem cell （haESC） approaches, which provide new platforms for gene function analysis, human disease modeling, and gene therapy. Here, we review the CRISPR/Cas9 and haESC technology for the generation of genetically modified mice and discuss the key challenges in the application of these approaches.

Recent Advances in Genetic Engineering of Microalgae

Metsbolites generated by microalgac cell metabolism have practical application value in the fields of medicine, food, feed and energy. At present, with the development of genetic engineering techniques and continuous reduction in gene sequencing costs, some micrcalgal genomes have been successively published, which enables specific genetic modification of microalgae according to human＇s demand and provides broad application prospects. In this paper, different mediating systems and emerging genome editing techniques were summarized, which laid the foundation for the application of genetic engineering methods for microalgae.

Current status and trends of wheat genetic transformation studies in China

More than 20 years have passed since the first report on successful genetic transformation of wheat. With the establishment and improvement of transformation platform, great progresses have been made on wheat genetic transformation both on its fundamental and applied studies in China, especially driven by the National Major Project for Transgenic Organism Breeding, China, initiated in 2008. In this review, wheat genetic transformation platform improvement and transgenic research progresses including new techniques applied and functional studies of wheat quality, yield and stress tolerant related genes and biosafety assessment are summarized. The existing problems and the trends in wheat transformation with traditional methods combined with genomic studies and genome editing technology are also discussed.

Repair of spinal cord injury by neural stem cells modified with BDNF gene in rats

Objective To explore repair of spinal cord injury by neural stem cells （NSCs） modified with brain derived neurotrophic factor （BDNF） gene （BDNF-NSCs） in rats. Methods Neural stem cells modified with BDNF gene were transplanted into the complete transection site of spinal cord at the lumbar 4 （L4） level in rats. Motor function of rats＇ hind limbs was observed and HE and X-gal immunoeytochemical staining, in situ hybridization, and retrograde HRP tracing were also performed. Results BDNF-NSCs survived and integrated well with host spinal cord. In the transplant group, some X-gal positive, NF-200 positive, GFAP positive, BDNF positive, and BDNF mRNA positive cells, and many NF-200 positive nerve fibers were observed in the injury site. Retrograde HRP tracing through sciatic nerve showed some HRP positive cells and nerve fibers near the rostral side of the injury one month after transplant and with time, they increased in number. Examinations on rats＇ motor function and behavior demonstrated that motor function of rats＇ hind limbs improved better in the transplant group than the injury group. Conclusion BDNF-NSCs can survive, differentiate, and partially integrate with host spinal cord, and they significantly ameliorate rats＇ motor function of hind limbs, indicating their promising role in repairing spinal cord injury.

Developmental Tendency of Dry Land Farming Technologies

The developmental tendency of dry land farming technologies in the semiarid area of China were reviewed based on the overview of recent progress in dry land farming researches from China and oversea. It was emphasized that conservation tillage, limited irrigation, genetic modification and chemical control are the important aspects for the dry land farming research and development of the future. In addition, some consid-

Targeting β-secretase with RNAi in neural stem cells for Alzheimer's disease therapy

There are several major pathological changes in Alzheimer＇s disease, including apoptosis of cho- linergic neurons, overactivity or overexpression of 13-site amyloid precursor protein cleaving enzyme 1 （BACE1） and inflammation. In this study, we synthesized a 19-nt oligonucleotide targeting BACE1, the key enzyme in amyloid beta protein （AI3） production, and introduced it into the pSilenCircle vector to construct a short hairpin （shRNA） expression plasmid against the BACE1 gene. We transfected this vector into C17.2 neural stem cells and primary neural stem cells, resulting in downregulation of the BACE1 gene, which in turn induced a considerable reduction in reducing AI3 protein production. We anticipate that this technique combining cell transplantation and gene ther- apy will open up novel therapeutic avenues for Alzheimer＇s disease, particularly because it can be used to simultaneously target several pathogenetic changes in the disease.

Priming strategies for controlling stem cell fate: Applications and challenges in dental tissue regeneration

Mesenchymal stromal cells(MSCs)have attracted intense interest in the field of dental tissue regeneration.Dental tissue is a popular source of MSCs because MSCs can be obtained with minimally invasive procedures.MSCs possess distinct inherent properties of self-renewal,immunomodulation,proangiogenic potential,and multilineage potency,as well as being readily available and easy to culture.However,major issues,including poor engraftment and low survival rates in vivo,remain to be resolved before large-scale application is feasible in clinical treatments.Thus,some recent investigations have sought ways to optimize MSC functions in vitro and in vivo.Currently,priming culture conditions,pretreatment with mechanical and physical stimuli,preconditioning with cytokines and growth factors,and genetic modification of MSCs are considered to be the main strategies;all of which could contribute to improving MSC efficacy in dental regenerative medicine.Research in this field has made tremendous progress and continues to gather interest and stimulate innovation.In this review,we summarize the priming approaches for enhancing the intrinsic biological properties of MSCs such as migration,antiapoptotic effect,proangiogenic potential,and regenerative properties.Challenges in current approaches associated with MSC modification and possible future solutions are also indicated.We aim to outline the present understanding of priming approaches to improve the therapeutic effects of MSCs on dental tissue regeneration.

Current state of research on non-human primate models of Alzheimer’s disease

With the increasingly serious aging of the global population, dementia has already become a severe clinical challenge on a global scale. Dementia caused by Alzheimer’s disease(AD) is the most common form of dementia observed in the elderly, but its pathogenetic mechanism has still not been fully elucidated. Furthermore, no effective treatment strategy has been developed to date, despite considerable efforts. This can be mainly attributed to the paucity of animal models of AD that are sufficiently similar to humans. Among the presently established animal models, non-human primates share the closest relationship with humans, and their neural anatomy and neurobiology share highly similar characteristics with those of humans. Thus, there is no doubt that these play an irreplaceable role in AD research. Considering this, the present literature on non-human primate models of AD was reviewed to provide a theoretical basis for future research.

Technical advances in NK cell-based cellular immunotherapy

Natural killer(NK)cells represent a promising future for tumor immunotherapy because of their unique biological functions and characteristics.This review focuses on technical advances in NK cell-based cellular immunotherapy and summarizes the developments of recent years in cell sources,genetic modification,manufacturing systems,clinical programs,and outcomes.Future prospects and challenges in NK cell immunotherapy are also discussed,including off-the-shelf NK cell exploitation,automatic and closed manufacturing systems,cryopreservation,and therapies involving regulatory checkpoints.

Multiple gene modifications of pigs for overcoming obstacles of xenotransplantation

Xenotransplantation,involving animal organ transplantation into humans to address the human organ shortage,has been studied since the 17th century.Early attempts to obtain organs from animals such as goats,dogs,and non-human primates proved unsuccessful.In the 1990s,scientists agreed that pigs were the most suitable donor animals for xenotransplantation.However,immune rejection between pig and human has hindered the application.To overcome these challenges,researchers developed genetically modified pigs that deactivate xenoreactive antigen genes and express human protective genes.These advances extended xenograft survival from days to years in non-human primates,resulting in the first human heart xenotransplant trial.Using genetically engineered pigs for the organ shortage is promising.This review provides an overview of potential incompatibilities of immunogenicity and functional proteins related to xenotransplantation between humans and pigs.Furthermore,it elucidates possible approaches for multiplex gene modification to breed better-humanized pigs for clinical xenotransplantation.

In-Silico Analysis &In-Vivo Results Concur on Glutathione Depletion in Glyphosate Resistant GMO Soy, Advancing a Systems Biology Framework for Safety Assessment of GMOs

This study advances previous efforts towards development of computational systems biology, in silico, methods for biosafety assessment of genetically modified organisms (GMOs). C1 metabolism is a critical molecular system in plants, fungi, and bacteria. In our previous research, critical molecular systems of C1 metabolism were identified and modeled using CytoSolve?, a platform for in silico analysis. In addition, multiple exogenous molecular systems affecting C1 metabolism such as oxidative stress, shikimic acid metabolism, glutathione biosynthesis, etc. were identified. Subsequent research expanded the C1 metabolism computational models to integrate oxidative stress, suggesting glutathione (GSH) depletion. Recent integration of data from the EPSPS genetic modification of Soy, also known as Roundup Ready Soy (RRS), with C1 metabolism predicts similar GSH depletion and HCHO accumulation in RRS. The research herein incorporates molecular systems of glutathione biosynthesis and glyphosate catabolism to expand the extant in silico models of C1 metabolism. The in silico results predict that Organic Soy will have a nearly 250% greater ratio of GSH and GSSG, a measure of glutathione levels, than in RRS that are glyphosate-treated glyphosate-resistant Soy versus the Organic Soy. These predictions also concur with in vivo greenhouse results. This concurrence suggests that these in silico models of C1 metabolism may provide a viable and validated platform for biosafety assessment of GMOs, and aid in selecting rational criteria for informing in vitro and in vivo efforts to more accurately decide in the problem formulation phase whose parameters need to be assessed so that conclusion on “substantial equivalence” or material difference of a GMO and its non-GMO counterpart can be drawn on a well-grounded basis.

The Role of the American Oil Chemists’Society in World Trade——Quality Assurance Testing,Certified Reference Materials,and International Liaison Activities

The American Oil Chemists’ Society(AOCS) is a volunteer-led association. AOCS develops and publishes methods of analysis for fats, oils, proteins, surfactants, and related materials according to accepted international standards to ensure equitable trade practices on a global scale. AOCS Official Method development has been going on for over a hundred years. The founding vision of AOCS in 1909 was "an organization designed for the development and advancement of analytical methods for cottonseed products." AOCS Official Methods are essential to world trade and are used to confirm the value of billions of pounds of oilseed-based commodities and finished products each year. In addition, AOCS conducts proficiency testing, provides certified reference materials, and collaborates with other standards developers including the International Organization for Standardization(ISO) and the Codex Alimentarius Commission. AOCS serves as a professional scientific membership organization providing current and emerging information as well as disseminating research results in oils, fats, lipids, proteins, surfactants, and related materials. Several avenues are used, especially meetings, publications, interest groups, networking opportunities, and web presence. Many scientists, experts, and others engaged in working in these fields find their professional "home" in AOCS. The AOCS Technical Leadership Committee comprises some of the most experienced AOCS members and scientists. The AOCS Technical Services department staff relies on this committee for guidance on scientific matters and for advice in prioritizing the opportunities facing AOCS.

Transient GUS and GFP Expression in Spanish Red Cedar(Cedrela odorata L.)Somatic Embryos.Optimization of Bombardment Conditions and Evaluation of Selective Agent Lethal Dose

Cedrela odorata is a tropical tree widely appreciated for its wood. Commercial plantations are frequently hampered by the attack of the meliacea borer, Hypsipyla grandella, and the lack of resistant varieties. C. odorata traditional breeding would consume very long periods of time, thus direct transfer of entomotoxic coding genes to generate resistant varieties is a promising alternative. There are two prerequisites for gene manipulation of this species: 1) to set the conditions for transgene delivery and 2) to have a way to select regenerating transformed plants. In this paper, we report the optimal biolistics conditions for transient expression of uidA and gfp reporter genes in C. odorata somatic embryos and the selective doses for kanamycin, spectinomycin, phosphinotrycin and hygromycin to screen transformed cells.

Engineered stem cells by emerging biomedical stratagems

Stem cell therapy holds immense potential as a viable treatment for a widespread range of intractable disorders.As the safety of stem cell transplantation having been demonstrated in numerous clinical trials,various kinds of stem cells are currently utilized in medical applications.Despite the achievements,the therapeutic benefits of stem cells for diseases are limited,and the data of clinical researches are unstable.To optimize tthe effectiveness of stem cells,engineering approaches have been developed to enhance their inherent abilities and impart them with new functionalities,paving the way for the next generation of stem cell therapies.This review offers a detailed analysis of engineered stem cells,including their clinical applications and potential for future development.We begin by briefly introducing the recent advances in the production of stem cells(induced pluripotent stem cells(ipsCs),embryonic stem cells(ESCs),mesenchymal stem cells(MSCs)and hematopoietic stem cells(HSCs).Furthermore,we present the latest developments of engineered strategies in stem cells,including engineered methods in molecular biology and biomaterial fields,and their application in biomedical research.Finally,we summarize the current obstacles and suggest future prospects for engineered stem cells in clinical translations and biomedical applications.

Genetic down-regulation of gibberellin results in semi-dwarf poplar but few non-target effects on chemical resistance and tolerance to defoliation

Aims Plant stature can be strongly modified via regulation of endog-enous levels and signalling of the plant hormone gibberellin(GA).Down-regulation of GA can produce semi-dwarf tree varieties with improved qualities such as reduced susceptibility to wind damage,enhanced root growth and more compact cultivation.However,these modifications may have unintended,non-target consequences for defence against herbivores,via either of two mechanisms:(i)reduced biomass production may cause trade-offs with chemical resistance traits,as predicted by the growth-differentiation balance hypothesis,and(ii)altered biomass allocation to either roots or pho-tosynthetic tissues may affect regrowth potential and thus tolerance to defoliation.Methods We studied GA down-regulated(GE)and non-transgenic wild-type hybrid poplar(Populus alba×P.tremula)in an outdoor,above-ground common garden and defoliated half of all replicate trees to simulate defoliation.We then quantified the independent and inter-active effects of genotype and defoliation on growth and chemical resistance-related traits,including phenolic glycosides(PGs),con-densed tannin and nitrogen.We also calculated tolerance to defo-liation as the differential in relative growth between undefoliated and defoliated trees.Important Findings Our results indicate that two of the four GA down-regulated geno-types had significantly reduced stem height,basal diameter,vol-ume(d2h),total biomass and increased allocation to leaves relative to the wild type.One of those two genotypes also had reduced allocation to roots.One and sometimes both of these same two genotypes also had at least 20%lower levels of condensed tannins and PGs and similar increases in lignin and nitrogen.Tolerance,as calculated by the differential in relative growth between unde-foliated and defoliated trees,was similar among all experimental genotypes.However,two GE genotypes flushed fewer leaves in response to defoliation relative to the wild type.Our results indi-cate that GA down-regulation strongly alters biomass production and allocation in poplar but does not necessarily compromise the ability of these trees to tolerate damage.However,some of the modifications we observed do have the potential to alter non-target resistance traits over time,and warrant further research,especially under plantation conditions.

Plant genetic engineering and genetically modified crop breeding: history and current status

This review charts the major developments in the genetic manipulation of plant cells that have taken place since the first gene transfer experiments using Ti plasmids in 1983. Tremendous progress has been made in both our scientific understanding and technological capabilities since the first genetically modified(GM)crops were developed with single gene resistances to herbicides, insects, viruses, and the silencing of undesirable genes. Despite opposition in some parts of the world, the area planted with first generation GM crops has grown from 1.7 Mhm^2 in 1996 to 179.7 Mhm^2 in 2015.The toolkit available for genetic modification has expanded greatly since 1996 and recently Nobel Laureates have called on Greenpeace to end their blanket opposition,and plant scientists have urged that consideration be given to the benefits of GM crops based on actual evidence. It is now possible to use GM to breed new crop cultivars resistant to a much wider range of pests and diseases, and to produce crops better able to adapt to climate change.The advent of new CRISPR-based technologies makes it possible to contemplate a much wider range of improvements based on transfer of new metabolic pathways and traits to improve nutritional quality, with a much greater degree of precision. Use of GM, sometimes in conjunction with other approaches, offers great opportunities for improving food quality, safety, and security in a changing world.

Understanding the genetic and epigenetic architecture in complex network of rice flowering pathways

Although the molecular basis of flowering time control is well dissected in the long day （LD） plant Arabidopsis, it is still largely unknown in the short day （SD） plant rice. Rice flowering time （heading date） is an important agronomic trait for season adaption and grain yield, which is affected by both genetic and environmental factors. During the last decade, as the nature of florigen was identified, notable progress has been made on exploration how florigen gene ,expression is genetically controlled. In Arabidopsis expression of certain key flowering integrators such as FLOWERING LOCUS C （FLC） and FLOWERING LOCUS T （FT） are also epige- netically regulated by various chromatin modifications, however, very little is known in rice on this aspect until very recently. This review summarized the advances of both genetic networks and chromatin modifications in rice flowering time control, attempting to give a complete view of the genetic and epigenetic architecture in complex network of rice flowering pathways.