Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “genetic modifiers”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 829 records · Page 46Linked to original sources
PubMed2005

Survival of genetically modified and self-cloned strains of commercial baker's yeast in simulated natural environments: environmental risk assessment.

Although genetic engineering techniques for baker's yeast might improve the yeast's fermentation characteristics, the lack of scientific data on the survival of such strains in natural environments as well as the effects on human health prevent their commercial use. Disruption of acid trehalase gene (ATH1) improves freeze tolerance, which is a crucial characteristic in frozen-dough baking. In this study, ATH1 disruptants constructed by genetic modification (GM) and self-cloning (SC) techniques were used as models to study such effects because these strains have higher freeze tolerance and are expected to be used commercially. Behavior of the strains in simulated natural environments, namely, in soil and water, was studied by measuring the change in the number of viable cells and in the concentration of DNA that contains ATH1 loci. Measurements were made using a real-time PCR method during 40 days of cultivation. Results showed that the number of viable cells of GM and SC strains decreased in a time-dependent manner and that the decrease rate was nearly equal to or higher than that for wild-type (WT) yeast. For all three strains (SC, GM, and WT) in the two simulated natural environments (water and soil), the DNA remained longer than did viable cells but the decrease patterns of either the DNA or the viable cells of SC and GM strains had tendencies similar to those of the WT strain. In conclusion, disruption of ATH1 by genetic engineering apparently does not promote the survival of viable cells and DNA in natural environments.

Cloning, Molecular↗
PubMedDate not supplied

[Genetically modified organisms: European and Italian legislation to protect citizens' health].

UNLABELLED: The development of GM foods and organisms has concentrated everyone's attention on the importance of food safety and on protecting citizens' health, and inevitably influenced healthcare policies regarding food safety. Personal ethical beliefs regarding food and in particular, the consumption of foods derived from biotechnology should be taken into account when deciding healthcare policy. AIM: The aim of this study was to analyse whether European, Italian and Regional legislation meets basic human rights regarding health and the right to choose, based on the precautionary principle. METHODS: European and Italian laws regarding the production and marketing of GM foods were analysed and compared to food safety legislation, in order to evaluate how and to what degree existing legislation protects consumers' right to choose. Results show that existing legislation protects consumers from possible foodborne diseases, but the right to informed consent and to free choice is not warranted. Existing laws do not attach enough importance to consumers' right to information; arbitrary threshold levels set for labeling and clauses concerning technical causes allow food businesses to avoid labeling and do not give consumers the possibility of making an informed choice.

Community Participation↗
PubMed2003

Clinical and laboratory investigation of allergy to genetically modified foods.

Technology has improved the food supply since the first cultivation of crops. Genetic engineering facilitates the transfer of genes among organisms. Generally, only minute amounts of a specific protein need to be expressed to obtain the desired trait. Food allergy affects only individuals with an abnormal immunologic response to food--6% of children and 1.5-2% of adults in the United States. Not all diseases caused by food allergy are mediated by IgE. A number of expert committees have advised the U.S. government and international organizations on risk assessment for allergenicity of food proteins. These committees have created decision trees largely based on assessment of IgE-mediated food allergenicity. Difficulties include the limited availability of allergen-specific IgE antisera from allergic persons as validated source material, the utility of specific IgE assays, limited characterization of food proteins, cross-reactivity between food and other allergens, and modifications of food proteins by processing. StarLink was a corn variety modified to produce a (Italic)Bacillus thuringiensis(/Italic) (Bt) endotoxin, Cry9C. The Centers for Disease Control and Prevention investigated 51 reports of possible adverse reactions to corn that occurred after the announcement that StarLink, allowed for animal feed, was found in the human food supply. Allergic reactions were not confirmed, but tools for postmarket assessment were limited. Workers in agricultural and food preparation facilities have potential inhalation exposure to plant dusts and flours. In 1999, researchers found that migrant health workers can become sensitized to certain Bt spore extracts after exposure to Bt spraying.

Animal Feed↗
PubMed1993

Challenges and opportunities for integrating genetically modified animals into traditional animal breeding plans.

Techniques have been developed to introduce specific genes from one species into the germplasm of another, including livestock. This paper reviews reports on evaluation, selection, and breeding procedures for introduction and multiplication of transgenes in breeding populations of livestock. Before transgenes are introduced and multiplied in commercial breeding populations, it is necessary to test transgenics extensively for both favorable and unfavorable transgene effects. Parent stock used to produce transgenic founder animals should be selected to excel in polygenic breeding value for economically important traits, especially if founder animals or their sons are to be used directly by AI in commercial populations. However, polygenic breeding value of founder transgenic animals and inbreeding depression are of negligible importance if a transgene is introgressed into a selection nucleus population from three or four generations of backcrossing. Transgenic development should be economically viable for traits with major effects on net merit, especially in the dairy industry, where transgenic sires can be used extensively by AI. A minimum effect of about 10% of the mean (or one phenotypic standard deviation) is a reasonable approximation of the minimum transgene effect that would be necessary to justify introgression into a nucleus swine population. A transgene effect of 10 to 20% of the mean would be required for most economic traits in beef cattle.

Animals↗
PubMed2000

Development of a genetically modified bacteriophage for use in tracing sources of pollution.

Bacteriophage are frequently used as biotracers to identify the source of water pollutants. Genetic manipulation of bacteriophage M13mp18 has been used to enhance this technique by creating a library in which each recombinant bacteriophage genome contains a unique identification sequence. Techniques that identify a recombinant bacteriophage by the presence of the identification sequence, including polymerase chain reaction, restriction site polymorphism and plaque hybridization, have been developed. Recombinant bacteriophage can be used to test a large number of suspected sources simultaneously. The identification sequence also eliminates confusion with natural bacteriophage present in water samples. The performance of the modified bacteriophage and the techniques were assessed in simulated field trials on a restricted site carried out under a consent for environmental release of a genetically modified organism. The techniques were also field tested at sites in northwest England using wild-type M13 bacteriophage.

Bacteriophage M13↗
PubMed2001

Cross-strain protection against clinical and laboratory strains of Pseudomonas aeruginosa mediated by dendritic cells genetically modified to express CD40 ligand and pulsed with specific strains of Pseudomonas aeruginosa.

We have shown that dendritic cells (DCs) genetically engineered with a recombinant adenovirus vector (Ad) to express CD40 ligand (CD40L) elicit specific humoral immunity against the Pseudomonas aeruginosa laboratory strain PAO1, without CD4(+) T cell help. In the present study, using several different strains of P. aeruginosa, we examine whether this strategy is generally applicable to enhancing clinically relevant pathogen-specific immunity. Mice immunized with DCs modified with CD40L and pulsed with heat-killed P. aeruginosa clinical strain PA514, originally isolated from the sputum of an individual with cystic fibrosis, survived lethal respiratory challenge with PA514-impregnated agar beads. Consistent with this effective in vivo protection, the immunized mice generated high levels of serum isotype-switched antibodies directed against PA514 without concomitant nonspecific elevations of total serum immunoglobulin levels. The CD40L genetically engineered DCs pulsed with seven of eight different strains of P. aeruginosa afforded significant, albeit variable, cross-protection against lethal respiratory challenge with a clinical (PA514) or laboratory (PAO1) strain of P. aeruginosa. CD40L genetically modified DCs pulsed with a clinical (PA514) or laboratory (PAO1) strain of P. aeruginosa initiated cross-reacting antibody responses against each other, but not against Escherichia coli and vice versa. These observations may be useful in developing vaccines for infectious diseases, including P. aeruginosa infection.

Adenoviridae↗
PubMed2026

Genetic modifiers of APOE-ε4-associated cognitive decline.

The APOE-ε4 allele is the strongest genetic risk factor for late-onset Alzheimer's disease. However, APOE-ε4 is not deterministic, highlighting the need to identify additional genetic and environmental factors. APOE-ε4 has been linked to accelerated cognitive decline, so we sought to investigate genetic factors that modify APOE-ε4-associated cognitive decline. We conduct cross-ancestry APOE-ε4-stratified and interaction GWAS using harmonized cognitive data from 32,778 participants, including 29,354 non-Hispanic White and 3,424 non-Hispanic Black individuals. Our primary outcome is late-life cognition, measured using harmonized composite scores for memory, executive function, and language, modeled as continuous traits reflecting both normative cognitive aging and disease-related decline. We identify two genome-wide significant loci in APOE-ε4 carriers, reaching genome-wide significance for executive function. These loci also demonstrate nominal associations across the other domains, suggesting broad effects on cognition. In non-carriers, we identify a genome-wide significant association at ITGB8 restricted to executive function, and another locus associated with language. We further link these loci to SEMA6D, GRIN3A, and ITGB8 through expression and methylation databases. Post-GWAS analyses implicate additional genes including SLCO1A2, and DNAH11. Genetic correlation analyses reveal differences by APOE-ε4 status for immune-related traits, suggesting immune-related predispositions may exacerbate cognitive risk in APOE-ε4 carriers.

Humans↗