Controlling transgene flow from engineered crops to unintended hosts by molecular approaches.

2021 ◽  
pp. 118-124
Author(s):  
C. Neal Stewart Jr
Keyword(s):  
Gene Flow ◽  
Male Sterility ◽  
Growth And Development ◽  
Management Strategies ◽  
Transgenic Crops ◽  
Molecular Approaches ◽  
Transgene Flow ◽  
Plant Sexual Reproduction ◽  
Crop Biotechnology ◽  
Hybridization And Introgression

Abstract For most transgenic crops, the purported ecological risk from transgenic-host hybridization and introgression to unintended host species is negligible. Nonetheless, there remains a risk-associated focus on the potential for gene flow in the governance and regulation of crop biotechnology. Because of uncertainties in the large world of biology as well as regulatory certainties (regulations will likely not diminish), researchers and stakeholders have a great interest in eliminating or substantially decreasing gene flow from transgenic crops. To that end, numerous approaches have been investigated for limiting transgene flow via hybridization and introgression to unintended hosts. While such bioconfinement may be accomplished by ecological and management strategies as discussed elsewhere in this book, this chapter focuses on mitigating unintended gene flow from engineered crops by way of genetic engineering itself. The chapter will mainly discuss the manipulation of relatively simple means to alter plant sexual reproduction and plant growth and development to control transgene flow, with the desired outcome being the prevention of transgenes from moving and/or introgression into free-living unintended hosts. These approaches include: (i) decreasing or delaying flowering; (ii) eliminating pollen production via male sterility or selective male sterility; (iii) removing transgenes from pollen or eggs by gene use restriction technologies; and (iv) kill switches. Emerging synthetic biology approaches that may be used for transgene bioconfinement are explored. Taken together, the same molecular biology strategies that are used to improve crops can also help assure their biosafety.

scholarly journals Gene flow from transgenic soybean, developed to obtain recombinant proteins for use in the skin care industry, to non-transgenic soybean

2020 ◽  
Vol 63 (1) ◽  
Author(s):  
Do Young Kim ◽  
Min Sik Eom ◽  
Hye Jin Kim ◽  
Eun Mi Ko ◽  
In-Soon Pack ◽  
...  
Keyword(s):  
Gene Flow ◽  
Growth Factor ◽  
Recombinant Proteins ◽  
Soybean Seed ◽  
Transgenic Crops ◽  
Skin Care ◽  
Transgenic Soybean ◽  
M Gene ◽  
Care Industry ◽  
Transgene Flow

Abstract Soybean has been recognized as a useful platform for heterologous protein production. This study compared the pollen characteristics of transgenic and non-transgenic soybean and investigated the rate of gene flow from transgenic soybean events, developed to obtain recombinant proteins (such as human epidermal growth factor, insulin-like growth factor 1, or thioredoxin) for use in the skin care industry, to non-transgenic soybean under field conditions, and determined the distance at which gene flow could occur. The lack of significant differences in pollen grain size, viability and pollen germination rates between transgenic and non-transgenic cultivars indicates that the overexpression of transgenes did not alter pollen characteristics in soybean. The highest rates of gene flow from the three transgenic soybean events to non-transgenic soybean ranged from 0.22 to 0.46% at the closest distance (0.5 m). Gene flow was observed up to 13.1 m from the transgenic plots. Our data fell within the ranges reported in the literature and indicate that an isolation distance greater than at least 13 m from transgenic soybean is required to prevent within-crop gene flow in soybean. As the potential markets for transgenic crops as a recombinant protein factory increase, gene flow from transgenic to non-transgenic conventional crops will become a key decision factor for policy makers during the approval process of transgenic crops. Our study may provide useful baseline data for the prevention of transgenic soybean seed contamination caused by transgene flow.

scholarly journals Current knowledge of gene flow in plants: implications for transgene flow

2003 ◽  
Vol 358 (1434) ◽  
pp. 1163-1170 ◽  
Author(s):  
Norman C. Ellstrand
Keyword(s):  
Gene Flow ◽  
Rare Species ◽  
Current Knowledge ◽  
Extinction Risk ◽  
Transgenic Crops ◽  
Wild Relatives ◽  
Wild Populations ◽  
Transgene Flow ◽  
Negative Impacts

Plant evolutionary biologists' view of gene flow and hybridization has undergone a revolution. Twenty–five years ago, both were considered rare and largely inconsequential. Now gene flow and hybridization are known to be idiosyncratic, varying with the specific populations involved. Gene flow typically occurs at evolutionarily significant rates and at significant distances. Spontaneous hybridization occasionally has important applied consequences, such as stimulating the evolution of more aggressive invasives and increasing the extinction risk for rare species. The same problems have occurred for spontaneous hybridization between crops and their wild relatives. These new data have implications for transgenic crops: (i) for most crops, gene flow can act to introduce engineered genes into wild populations; (ii) depending on the specific engineered gene(s) and populations involved, gene flow may have the same negative impacts as those observed for traditionally improved crops; (iii) gene flow's idiosyncratic nature may frustrate management and monitoring attempts; and (iv) intercrop transgene flow, although rarely discussed, is equally worthy of study.

scholarly journals Hermansky-Pudlak Syndrome and Lung Disease: Pathogenesis and Therapeutics

2021 ◽  
Vol 12 ◽  
Author(s):  
Pamela Velázquez-Díaz ◽  
Erika Nakajima ◽  
Parand Sorkhdini ◽  
Ashley Hernandez-Gutierrez ◽  
Adam Eberle ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Molecular Mechanisms ◽  
Management Strategies ◽  
Oculocutaneous Albinism ◽  
Alveolar Epithelial Cells ◽  
Multisystem Disorder ◽  
Alveolar Epithelial ◽  
Novel Treatments ◽  
Molecular Approaches ◽  
Hermansky Pudlak Syndrome

Hermansky-Pudlak Syndrome (HPS) is a rare, genetic, multisystem disorder characterized by oculocutaneous albinism (OCA), bleeding diathesis, immunodeficiency, granulomatous colitis, and pulmonary fibrosis. HPS pulmonary fibrosis (HPS-PF) occurs in 100% of patients with subtype HPS-1 and has a similar presentation to idiopathic pulmonary fibrosis. Upon onset, individuals with HPS-PF have approximately 3 years before experiencing signs of respiratory failure and eventual death. This review aims to summarize current research on HPS along with its associated pulmonary fibrosis and its implications for the development of novel treatments. We will discuss the genetic basis of the disease, its epidemiology, and current therapeutic and clinical management strategies. We continue to review the cellular processes leading to the development of HPS-PF in alveolar epithelial cells, lymphocytes, mast cells, and fibrocytes, along with the molecular mechanisms that contribute to its pathogenesis and may be targeted in the treatment of HPS-PF. Finally, we will discuss emerging new cellular and molecular approaches for studying HPS, including lentiviral-mediated gene transfer, induced pluripotent stem cells (iPSCs), organoid and 3D-modelling, and CRISPR/Cas9-based gene editing approaches.

Assessing environmental impact of pollen-mediated transgene flow.

2021 ◽  
pp. 1-25
Author(s):  
Bao-Rong Lu
Keyword(s):  
Gene Flow ◽  
Environmental Impact ◽  
Case Studies ◽  
Environmental Impacts ◽  
Genetically Engineered ◽  
Weedy Rice ◽  
Fitness Effect ◽  
Trade Disputes ◽  
Transgene Flow

Abstract Potential environmental impact caused by pollen-mediated transgene flow from commercially cultivated genetically engineered (GE) crops to their non-GE crop counterparts and to their wild and weedy relatives has aroused tremendous biosafety concerns worldwide. This chapter provides information on the concept and classification of gene flow, the framework of the environmental biosafety assessment caused by pollen-mediated gene flow, and relevant case studies about transgene flow and its environmental impact. In general, gene flow refers to the movement of genes or genetic materials from a plant population to other populations. Crop-to- crop transgene flow at a considerable frequency may result in transgene 'contamination' of non-GE crops, causing potential food/feed biosafety problems and regional or international trade disputes. Crop-to- wild/weedy transgene flow may bring about environmental impacts, such as creating more invasive weeds, threatening local populations of wild relative species, or affecting genetic diversity of wild relatives, if the incorporated transgene can normally express in the recipient wild/weedy plants and significantly alter the fitness of the wild/weedy plants and populations. It is therefore necessary to establish a proper protocol to assess the potential environmental impacts caused by transgene flow. Three steps are important for assessing potential environment impacts of transgene flow to wild/weedy relatives: (i) to accurately measure the frequencies of transgene flow: (ii) to determine the expression level of a transgene incorporated in wild/weedy populations; and (iii) to estimate the fitness effect (benefit or cost) conferred by expression of a transgene in wild/weedy populations. The recently reported case of non-random allele transmission into GE and non-GE hybrid lineages or experimental populations challenges the traditional method of estimating the fitness effect for the assessment of environmental impacts of transgene flow. Furthermore, case studies of transgenic mitigation (TM) strategies illustrate ways that may reduce the impacts of a transgene on wild/weedy populations if crop-to- wild/weedy transgene flow is not preventable, such as in the case of gene flow from crop rice to its co-occurring weedy rice.

scholarly journals Outdoor trapping and genetical characterization of populations of the webbing clothes moth Tineola bisselliella (Lepidoptera: Tineidae) in the broader area of Berlin

2011 ◽  
Vol 43 (2) ◽  
pp. 129 ◽  
Author(s):  
Bianca Krüger-Carstensen ◽  
Rudy Plarre
Keyword(s):  
Gene Flow ◽  
Pest Management ◽  
Management Strategies ◽  
Seasonal Abundance ◽  
Subspecies Level ◽  
Culture Heritage ◽  
The City ◽  
Species Mobility ◽  
Tineola Bisselliella

Adapted and effective pest management strategies for the protection of irreplaceable culture heritage as well as for the prevention of damages in households and warehouses are based on reliable information about the presence and distribution of the pest organisms. Monitoring the webbing clothes moth <em>Tineola bisselliella </em>at thirteen outdoor stations in the broader area of Berlin give a first idea of their occurrence in an urban area and the hinterlands. The results demonstrate a seasonal abundance in the city and a missing of this species in the countryside. Data suggest a synanthropic occurrence of the webbing clothes moth rather than an invasion from natural reservoires. Possible molecular examinations on the species and subspecies level are presented to analyze the gene flow between populations and give an impression of species mobility as well as pathways of infestation.

The effects of local selection versus dispersal on insecticide resistance patterns: longitudinal evidence from diamondback moth (Plutella xylostella (Lepidoptera: Plutellidae)) in Australia evolving resistance to pyrethroids

2008 ◽  
Vol 98 (2) ◽  
pp. 145-157 ◽  
Author(s):  
N.M. Endersby ◽  
P.M. Ridland ◽  
A.A. Hoffmann
Keyword(s):  
Gene Flow ◽  
Plutella Xylostella ◽  
Diamondback Moth ◽  
Management Strategies ◽  
Resistance Management ◽  
Synthetic Pyrethroids ◽  
Forage Crops ◽  
Microsatellite Variation ◽  
Resistance Evolution ◽  
Local Selection

AbstractWhen strong directional selection acts on a trait, the spatial distribution of phenotypes may reflect effects of selection, as well as the spread of favoured genotypes by gene flow. Here we investigate the relative impact of these factors by assessing resistance to synthetic pyrethroids in a 12-year study of diamondback moth, Plutella xylostella, from southern Australia. We estimated resistance levels in populations from brassicaceous weeds, canola, forage crops and vegetables. Differences in resistance among local populations sampled repeatedly were stable over several years. Levels were lowest in samples from weeds and highest in vegetables. Resistance in canola samples increased over time as insecticide use increased. There was no evidence that selection in one area influenced resistance in adjacent areas. Microsatellite variation from 13 populations showed a low level of genetic variation among populations, with an AMOVA indicating that population only accounted for 0.25% of the molecular variation. This compared to an estimate of 13.8% of variation accounted for by the resistance trait. Results suggest that local selection rather than gene flow of resistance alleles dictated variation in resistance across populations. Therefore, regional resistance management strategies may not limit resistance evolution.

Kokanee–sockeye salmon hybridization leads to intermediate morphology and resident life history: implications for fisheries management

2020 ◽  
Vol 77 (2) ◽  
pp. 355-364
Author(s):  
Lucas D. Elliott ◽  
Hillary G.M. Ward ◽  
Michael A. Russello
Keyword(s):  
Life History ◽  
Sockeye Salmon ◽  
Management Strategies ◽  
Empirical Support ◽  
Intermediate Morphology ◽  
Intermediate Size ◽  
Freshwater Resident ◽  
Historical Range ◽  
Hybridization And Introgression

Stocking programs designed to return extirpated species to their historical range have become increasingly prevalent, punctuating the need to better understand the risks posed to recipient ecosystems. Here, we investigated the genetic and biological consequences of an anadromous sockeye salmon (Oncorhynchus nerka) stocking program in Skaha Lake, British Columbia, where substantial levels of hybridization and introgression with the native freshwater resident ecotype (kokanee) have been detected. We genetically assigned 543 individuals (adult spawners, age-0 juveniles) to estimate stock proportions (pure-stock sockeye, pure-stock kokanee, or hybrid) between 2010 and 2017, with a subset undergoing otolith microchemistry analysis to determine migratory life history and maternal ancestry. The proportion of hybrid spawners varied from 5% to 20% across sampling years, while that of hybrid age-0 juveniles remained relatively constant (∼11%). Hybrid spawners exhibited intermediate size relative to pure stocks, with the vast majority being nonanadromous (92%) and of resident maternal ancestry (76%). Our results provide empirical support for previously hypothesized mechanisms of hybridization between O. nerka life-history forms and underscore the importance of continued monitoring of stocking programs to quantify long-term fitness impacts of introgression and refine management strategies.

scholarly journals Voter Model and Biased Voter Model in Heterogeneous Environments

2007 ◽  
Vol 44 (03) ◽  
pp. 770-787
Author(s):  
N. Lanchier ◽  
C. Neuhauser
Keyword(s):  
Gene Flow ◽  
Pollen Dispersal ◽  
Transgenic Crops ◽  
Wild Relatives ◽  
Voter Model ◽  
Wild Plants ◽  
Transgenic Crop ◽  
Heterogeneous Environments ◽  
Wild Type ◽  
Type Gene

With the rapid adoption of transgenic crops, gene flow from transgenic crops to wild relatives through pollen dispersal is of significant concern and warrants both empirical and theoretical studies to assess the risk of introduction of transgenes into wild populations. We propose to use the (biased) voter model in a heterogeneous environment to investigate the effects of recurrent gene flow from transgenic crop to wild relatives. The model is defined on the d-dimensional integer lattice that is divided into two parts, Δ and Z d \ Δ. Individuals carrying the transgene and individuals carrying the wild type gene compete according to the evolution rules of a (biased) voter model on Z d \ Δ, while the process is conditioned to have only individuals carrying the transgene on Δ. Our main findings suggest that unless transgenes confer increased fitness in wild relatives, introgression of transgenes into populations of wild plants is slow and may even be reversible without intervention. Our study also addresses the effects of different spatial planting patterns of transgenic crops on the rate of introgression.

scholarly journals Morphometric Variation as an Indicator of Genetic Interactions Between Black-Capped and Carolina Chickadees at a Contact Zone in the Appalachian Mountains

The Auk ◽  
2000 ◽  
Vol 117 (2) ◽  
pp. 427-444 ◽  
Author(s):  
Gene D. Sattler ◽  
Michael J. Braun
Keyword(s):  
Genetic Variation ◽  
Gene Flow ◽  
Genetic Markers ◽  
Hybrid Zone ◽  
Morphological Variation ◽  
Genetic Data ◽  
Mixed Ancestry ◽  
Morphometric Variation ◽  
Average Gene ◽  
Hybridization And Introgression

AbstractWe studied hybridization and introgression between Black-capped (Poecile atricapillus) and Carolina (P. carolinensis) chickadees along two transects in the Appalachians using four genetic markers and multivariate analysis of morphology. Genetic data revealed that at least 58% of the birds in the center of each transect were of mixed ancestry and that recombinant genotypes predominated among hybrids, demonstrating that hybridization is frequent and that many hybrids are fertile. Genetic clines generally were steep and coincident in position, but introgression was evident well beyond the range interface. Introgression was higher at the one autosomal locus surveyed than in mitochondrial DNA or in two sex-linked markers, suggesting that the hybrid zone is a conduit for gene flow between the two forms at some loci. On a broad scale, morphometric variation was concordant with genetic variation. Clines in morphological variation based on principal components (PC) scores were steep and coincident with genetic clines. Also, a strong correlation within a population between PC scores and an individual's genetic makeup suggested that a large amount of morphological variation was genetically determined. However, morphological analysis indicated that hybrids were uncommon on one transect, whereas genetic data clearly showed that they were common on both. In addition, patterns of morphological variation were equivocal regarding introgression across the hybrid zone. Thus, genetic data provided a complementary and more detailed assessment of hybridization, largely due to the discrete nature of genetic variation. Genetic markers are useful in understanding hybridization and introgression, but diagnostic markers may underestimate average gene flow if selection against hybrids maintains steep clines at diagnostic loci. To gain a clearer picture of the genome-wide effects of hybridization, a much larger number of loci must be assayed, including non-diagnostic ones.

Dispersal and gene flow in the habitat-forming kelp, Ecklonia radiata: relative degrees of isolation across an east - west coastline

2009 ◽  
Vol 60 (8) ◽  
pp. 802 ◽  
Author(s):  
M. A. Coleman ◽  
B. M. Gillanders ◽  
S. D. Connell
Keyword(s):  
Gene Flow ◽  
Anthropogenic Impacts ◽  
Spatial Scales ◽  
Management Strategies ◽  
South Australia ◽  
Rocky Reef ◽  
Ecklonia Radiata ◽  
Island Populations ◽  
Oceanic Currents ◽  
East West

Characterising patterns of dispersal and gene flow in habitat-forming organisms is becoming a focal concern for conservation and management strategies as anthropogenic impacts drive change in coastal ecosystems. Here, we use six microsatellite markers to characterise dispersal and gene flow across the South Australian distribution of the habitat-forming kelp Ecklonia radiata. Populations of E. radiata on subtidal reefs in South Australia were highly genetically structured on large (100s of km, FST = 0.211) and small (10s of km, FST = 0.042) spatial scales with the extent of differentiation positively correlated with geographic distances among populations. Neither the presence of oceanic currents nor intervening rocky reef habitats appeared to facilitate widespread gene flow. There was a trend for island populations to be more genetically differentiated from those on the mainland and to have slightly greater levels of heterozygosity than mainland populations. Our results show relatively low dispersal and gene flow suggesting that recovery following kelp loss may be slow. Such information not only provides insights into relative rates of recovery, but may also identify which populations may be best used for propagation and restoration efforts.

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